AfterSales Training. Drivetrain Repair Sports Cars P-30

Transcription

1 AfterSales Training Drivetrain Repair Sports Cars P-30

2 Porsche AfterSales Training Student Name: Training Center Location: Instructor Name: Date: Important Notice: Some of the contents of this AfterSales Training brochure was originally written by Porsche AG for its restof-world English speaking market. The electronic text and graphic files were then imported by Porsche Cars N.A, Inc. and edited for content. Some equipment and technical data listed in this publication may not be applicable for our market. Specifications are subject to change without notice. We have attempted to render the text within this publication to American English as best as we could. We reserve the right to make changes without notice Porsche Cars North America, Inc. All Rights Reserved. Reproduction or translation in whole or in part is not permitted without written authorization from publisher. AfterSales Training Publications Dr. Ing. h.c. F. Porsche AG is the owner of numerous trademarks, both registered and unregistered, including without limitation the Porsche Crest, Porsche, Boxster, Carrera, Cayenne, Cayman, Panamera, Tiptronic, VarioCam, PCM, 911, 4S, FOUR, UNCOMPROMISED. SM and the model numbers and distinctive shapes of Porsche's automobiles such as, the federally registered 911 and Boxster automobiles. The third party trademarks contained herein are the properties of their respective owners. Specifications, performance standards, options, and other elements shown are subject to change without notice. Some vehicles may be shown with non-u.s. equipment. Porsche recommends seat belt usage and observance of traffic laws at all times. Printed in the USA Part Number - PNA P Edition - 2/10

3 Table of Contents Description Section Transmission Type Designations Boxster (986) Transmission Boxster & Cayman (987) Transmission Turbo (996) Transmission GT2/GT3 (996) Transmission Tiptronic Transmission Porsche Doppelkupplung (PDK) Transmission Final Drive Setup Conversion Charts Drivetrain Repair Sports Cars

4 Drivetrain Repair Sports Cars

5 Transmission Type Designations Transmission Number Identification Digit: Example: G Transmission Type: Transmission Version: Index of Variants: Serial Number: 911, Boxster and Cayman Transmission Type Designations Since Model Year 1989 Model Transmission Technical Installed In Year Type Data 1989 G Speed M/T 911 Carrera - RoW G Speed M/T 911 Carrera - USA, Australia, Japan G Speed M/T 911 Carrera - Switzerland G Speed M/T 911 Turbo - World-Wide G Speed M/T 911 Carrera (964) - RoW, USA/Canada G Speed M/T 911 Carrera 4 (964) - Switzerland 1990 A Speed A/T 911 Carrera 2 (964) - RoW, USA/Canada G Speed M/T 911 Carrera 2 (964) - RoW, USA/Canada G Speed M/T 911 Carrera 2 (964) - Switzerland G Speed M/T 911 Carrera 4 (964) - RoW, USA/Canada G Speed M/T 911 Carrera 4 (964) - Switzerland 1991 A Speed A/T 911 Carrera 2 (964) - RoW, USA/Canada G Speed M/T 911 Carrera 2 (964) - RoW, USA/Canada G Speed M/T 911 Carrera 2 (964) - Switzerland G Speed M/T 911 Turbo (964) - World-Wide G Speed M/T 911 Carrera 4 (964) - RoW, USA/Canada G Speed M/T 911 Carrera 4 (964) - Switzerland 1992 A Speed A/T 911 Carrera 2 (964) - RoW A Speed A/T 911 Carrera 2 (964) - USA/Canada G Speed M/T 911 Carrera 2 (964) - RoW G Speed M/T 911 Carrera 2 (964) - Switzerland G Speed M/T 911 Carrera 2 (964) - USA/Canada G Speed M/T 911 Carrera 2 RS (964) - RoW G Speed M/T 911 Turbo (964) - World-Wide G Speed M/T 911 Carrera 4 (964) - RoW, USA/Canada G Speed M/T 911 Carrera 4 (964) - Switzerland G Speed M/T 911 Carrera 4 (964) - Taiwan Drivetrain Repair Sports Cars Page 1.1

6 Transmission Type Designations Model Transmission Technical Installed In Year Type Data 1993 A Speed A/T 911 Carrera 2 (964) - RoW A Speed A/T 911 Carrera 2 (964) - USA/Canada, Taiwan G Speed M/T 911 Carrera 2 (964) - RoW G Speed M/T 911 Carrera 2 (964) - Switzerland/Taiwan G Speed M/T 911 Carrera 2 (964) - USA/Canada G Speed M/T 911 Carrera 2 RS (964) - RoW G Speed M/T 911 Carrera 4 (964) - RoW, USA G Speed M/T 911 Carrera 4 (964) - Switzerland G Speed M/T 911 Carrera 4 (964) - Taiwan 1994 A Speed A/T 911 Carrera 2 (964) - RoW A Speed A/T 911 Carrera 2 (964) - USA/Canada, Taiwan G Speed M/T 911 Carrera 2 (964) - RoW G Speed M/T 911 Carrera 2 (964) - Switzerland/Taiwan G Speed M/T 911 Carrera 2 (964) - USA/Canada G Speed M/T 911 Carrera 2 RS (964) - RoW G Speed M/T 911 Turbo 3.6 (964) - World-Wide G Speed M/T 911 Carrera 4 (964) - RoW, USA G Speed M/T 911 Carrera 4 (964) - Switzerland G Speed M/T 911 Carrera 4 (964) - Taiwan 1995 A Speed A/T 911 Carrera 2 (993) - RoW A Speed A/T 911 Carrera 2 (993) - USA/Canada, Taiwan G Speed M/T 911 Carrera (993) - USA/Canada G Speed M/T 911 Carrera (993) - RoW 1996 A Speed A/T 911 Carrera 2 (993) - RoW A Speed A/T 911 Carrera 2 (993) - USA/Canada, Taiwan G Speed M/T 911 Carrera 2 (993) - USA/Canada G Speed M/T 911 Carrera 2 (993) - RoW G Speed M/T 911 Carrera 4 (993) - USA/Canada G Speed M/T 911 Carrera 4 (993) - RoW G Speed M/T 911 Turbo (993) - World-Wide 1997 A Speed A/T 911 Carrera 2 (993) - RoW A Speed A/T 911 Carrera 2 (993) - USA/Canada, Taiwan G Speed M/T 911 Carrera 2 (993) - RoW, USA/Canada G Speed M/T 911 Carrera 4 (993) - RoW, USA/Canada G Speed M/T 911 Turbo (993) - World-Wide A Speed A/T Boxster (986) G Speed M/T Boxster (986) 1998 A Speed A/T 911 Carrera 2 (993) - RoW A Speed A/T 911 Carrera 2 (993) - USA/Canada, Taiwan G Speed M/T 911 Carrera 2 (993) - RoW, USA/Canada G Speed M/T 911 Carrera 4/4S (993) - RoW, USA/Canada G Speed M/T 911 Turbo (993) - Taiwan G Speed M/T 911 Turbo (993) - RoW, USA/Canada A Speed A/T Boxster (986) G Speed M/T Boxster (986) Page 1.2 Drivetrain Repair Sports Cars

7 Transmission Type Designations Model Transmission Technical Installed In Year Type Data 1999 A Speed A/T Boxster (986) G Speed M/T Boxster (986) A Speed A/T 911 Carrera 2 (996) - RoW, USA/Canada A Speed A/T 911 Carrera 4 (996) - RoW, USA/Canada G Speed M/T 911 Carrera 2 (996) - RoW, USA/Canada G Speed M/T 911 Carrera 4 (996) - RoW, USA/Canada 2000 A Speed A/T Boxster (986) A Speed A/T Boxster S (986) G Speed M/T Boxster (986) G Speed M/T Boxster S (986) A Speed A/T 911 Carrera 2 (996) - RoW, USA/Canada A Speed A/T 911 Carrera 4 (996) - RoW, USA/Canada G Speed M/T 911 Carrera 2 (996) - RoW, USA/Canada G Speed M/T 911 Carrera 4 (996) - RoW, USA/Canada G Speed M/T 911 GT3 (996) - RoW 2001 A Speed A/T Boxster (986) A Speed A/T Boxster S (986) G Speed M/T Boxster (986) G Speed M/T Boxster S (986) A Speed A/T 911 Carrera 2 (996) - RoW, USA/Canada A Speed A/T 911 Carrera 4 (996) - RoW, USA/Canada G Speed M/T 911 Carrera 2 (996) - RoW, USA/Canada G Speed M/T 911 Carrera 4 (996) - RoW, USA/Canada G Speed M/T 911 Turbo (996) - World-Wide A Speed A/T 911 Turbo (996) - World-Wide G Speed M/T 911 GT2 (996) - World-Wide G Speed M/T 911 GT3 (996) - RoW 2002 A Speed A/T Boxster (986) A Speed A/T Boxster S (986) G Speed M/T Boxster (986) G Speed M/T Boxster S (986) A Speed A/T 911 Carrera 2 (996) - RoW, USA/Canada A Speed A/T 911 Carrera 4 (996) - RoW, USA/Canada G Speed M/T 911 Carrera 2 (996) - RoW, USA/Canada G Speed M/T 911 Carrera 4 (996) - RoW, USA/Canada G Speed M/T 911 Turbo (996) - World-Wide A Speed A/T 911 Turbo (996) - World-Wide G Speed M/T 911 GT2 (996) - World-Wide Drivetrain Repair Sports Cars Page 1.3

8 Transmission Type Designations Model Transmission Technical Installed In Year Type Data 2003 A Speed A/T Boxster (986) A Speed A/T Boxster S (986) G Speed M/T Boxster (986) G Speed M/T Boxster S (986) A Speed A/T 911 Carrera 2 (996) - RoW, USA/Canada A Speed A/T 911 Carrera 4 (996) - RoW, USA/Canada G Speed M/T 911 Carrera 2 (996) - RoW, USA/Canada G Speed M/T 911 Carrera 4 (996) - RoW, USA/Canada G Speed M/T 911 Turbo (996) - World-Wide A Speed A/T 911 Turbo (996) - World-Wide G Speed M/T 911 GT2 (996) - World-Wide 2004 A Speed A/T Boxster (986) A Speed A/T Boxster S (986) G Speed M/T Boxster (986) G Speed M/T Boxster S (986) A Speed A/T 911 Carrera 2 (996) - RoW, USA/Canada A Speed A/T 911 Carrera 4 (996) - RoW, USA/Canada G Speed M/T 911 Carrera 2 (996) - RoW, USA/Canada G Speed M/T 911 Carrera 4 (996) - RoW, USA/Canada G Speed M/T 911 Turbo (996) - World-Wide A Speed A/T 911 Turbo (996) - World-Wide G Speed M/T 911 GT2 (996) - World-Wide G Speed M/T 911 GT3 (996) - USA/Canada 2005 A Speed A/T Boxster (987) A Speed A/T Boxster S (987) G Speed M/T Boxster (987) G Speed M/T Boxster S (987) A Speed A/T 911 Carrera 2 (996) - RoW, USA/Canada A Speed A/T 911 Carrera 4 (996) - RoW, USA/Canada G Speed M/T 911 Carrera 2 (996) - RoW, USA/Canada G Speed M/T 911 Carrera 4 (996) - RoW, USA/Canada A Speed A/T 911 Carrera/S (997) - RoW, USA/Canada G Speed M/T 911 Carrera/S (997) - RoW, USA/Canada G Speed M/T 911 Turbo (996) - World-Wide A Speed A/T 911 Turbo (996) - World-Wide G Speed M/T 911 GT2 (996) - World-Wide G Speed M/T 911 GT3 (996) - USA/Canada 2006 A Speed A/T Boxster (987) A Speed A/T Boxster S (987) G Speed M/T Boxster (987) G Speed M/T Boxster S (987) A Speed A/T Cayman S (987) G Speed M/T Cayman S (987) A Speed A/T 911 Carrera 2/S (997) - RoW, USA/Canada G Speed M/T 911 Carrera 2/S (997) - RoW, USA/Canada A Speed A/T 911 Carrera 4/S (997) - RoW, USA/Canada G Speed M/T 911 Carrera 4/S (997) - RoW, USA/Canada Page 1.4 Drivetrain Repair Sports Cars

9 Transmission Type Designations Model Transmission Technical Installed In Year Type Data 2007 A Speed A/T Boxster (987) A Speed A/T Boxster S (987) G Speed M/T Boxster (987) G Speed M/T Boxster S (987) A Speed A/T Cayman (987) A Speed A/T Cayman S (987) G Speed M/T Cayman (987) G Speed M/T Cayman S (987) A Speed A/T 911 Carrera 2/S (997) - RoW, USA/Canada G Speed M/T 911 Carrera 2/S (997) - RoW, USA/Canada A Speed A/T 911 Carrera 4/S (997) - RoW, USA/Canada G Speed M/T 911 Carrera 4/S (997) - RoW, USA/Canada G Speed M/T 911 Turbo (997) - World-Wide A Speed A/T 911 Turbo (997) - World-Wide G Speed M/T 911 GT3 (997) - USA/Canada 2008 A Speed A/T Boxster (987) A Speed A/T Boxster S (987) G Speed M/T Boxster (987) G Speed M/T Boxster S (987) A Speed A/T Cayman (987) A Speed A/T Cayman S (987) G Speed M/T Cayman (987) G Speed M/T Cayman S (987) A Speed A/T 911 Carrera 2/S (997) - RoW, USA/Canada G Speed M/T 911 Carrera 2/S (997) - RoW, USA/Canada A Speed A/T 911 Carrera 4/S (997) - RoW, USA/Canada G Speed M/T 911 Carrera 4/S (997) - RoW, USA/Canada G Speed M/T 911 Turbo (997) - World-Wide A Speed A/T 911 Turbo (997) - World-Wide G Speed M/T 911 GT2 (997) - World-Wide G Speed M/T 911 GT3 (997) - USA/Canada 2009 CG Speed PDK Boxster (987) CG Speed PDK Boxster S (987) G Speed M/T Boxster (987) G Speed M/T Boxster S (987) CG Speed PDK Cayman (987) CG Speed PDK Cayman S (987) G Speed M/T Cayman (987) G Speed M/T Cayman S (987) CG Speed PDK 911 Carrera 2/S (997) - RoW, USA/Canada G Speed M/T 911 Carrera 2/S (997) - RoW, USA/Canada CG Speed PDK 911 Carrera 4/S (997) - RoW, USA/Canada G Speed M/T 911 Carrera 4/S (997) - RoW, USA/Canada G Speed M/T 911 Turbo (997) - World-Wide A Speed A/T 911 Turbo (997) - World-Wide G Speed M/T 911 GT2 (997) - World-Wide Drivetrain Repair Sports Cars Page 1.5

10 Transmission Type Designations Model Transmission Technical Installed In Year Type Data 2010 CG Speed PDK Boxster (987) CG Speed PDK Boxster S (987) G Speed M/T Boxster (987) G Speed M/T Boxster S (987) CG Speed PDK Cayman (987) CG Speed PDK Cayman S (987) G Speed M/T Cayman (987) G Speed M/T Cayman S (987) CG Speed PDK 911 Carrera 2/S (997) - RoW, USA/Canada G Speed M/T 911 Carrera 2/S (997) - RoW, USA/Canada CG Speed PDK 911 Carrera 4/S (997) - RoW, USA/Canada G Speed M/T 911 Carrera 4/S (997) - RoW, USA/Canada G Speed M/T 911 Turbo (997) - World-Wide CG Speed PDK 911 Turbo (997) - World-Wide G Speed M/T 911 GT3 (997) - World-Wide Page 1.6 Drivetrain Repair Sports Cars

11 Boxster (986) Transmission Subject Page General Information Boxster Transmission Dual-mass Flywheel Gears Pinion Shaft Bearing Lubrication Boxster Gear Ratios Synchromesh Boxster Shifter, 5-speed Reverse Gear Lock Drivetrain Repair Sports Cars Page 2.1

12 Boxster (986) Transmission General The Boxster came equipped with a Five-speed and the Boxster S with a Six-speed manual transmission, both models offered the optional Tiptronic automatic transmission. This section will only cover the Boxster G86.00/01 5-speed transmissions. Manual Transmission Types: Boxster (986) G86.00 M.Y G86.01 M.Y Boxster S (986) G86.20 M.Y Manual Transmission G86.01 Boxster (986) The transmission ratios of the 5-speed Boxster manual gearbox have been adapted to the increased engine performance respectively the higher engine torque. Dual-Mass Flywheel/Clutch G86.00 Gear Sets Boxster (986) Gear Sets and Shafts The G transmission is a two-shaft transmission with an overhead drive shaft and hypoid drive assembly. All of the forwards gears as well as the reverse gear have external cone synchronization. The first, second, and the reverse gear are permanent components of the triple-bearing drive shaft. The pinion shaft runs on two tapered roller bearings. G86.00 Pinion Shaft Bearing Boxster (986) Longitudinal Adjustment Of Pinion Shaft Bearing Installation of a rubber plate (1) at the rear tapered-roller bearing (3) carrying the pinion shaft means that the set bearing tensioning is maintained within the specified tolerances, even when the transmission case expands due to heating. Dual-mass Flywheel, Pressure Plate and Clutch Disk The working cycles and the firing order of the engine cause speed fluctuations resulting in irregularities which lead to torsional vibrations along the entire drive train. These torsional vibrations may cause all loose parts not powered and with play to rattle, chatter, or bounce (loose gearwheels, parts of the synchronization system, switch components). This may result in annoying transmission noise, especially at low engine speeds. As with previous Porsche vehicles, the Boxster has a twomass flywheel (TMF) to prevent these noises. The singledisk dry clutch with asbestos-free clutch plates is bolted to the TMF. Pinion Shaft Bearing Functional Description In an enclosed space, the rubber plate behaves like a liquid, the pressure is uniformly distributed to all sides. The rubber plate is installed in the case cover with a defined pretension force and compensates the change in length as the transmission case heats up as a result of axial displacement of the pressure plate (2) against the bevel gear bearing. As a result, the friction moment of the tapered-roller bearing remains within the predefined tolerance limits in all operating conditions. Page 2.2 Drivetrain Repair Sports Cars

13 Boxster (986) Transmission G86.00 Transmission Cutout G86.00 Oil Supply Boxster (986) To reduce losses due to splashing and to increase efficiency, the oil level has been kept low with a 2.25 liter oil capacity. This means that oil must be supplied using an oil drip shaft to lubricate the loose gearwheels on the drive shaft and the rear transmission bearing. Functional Description Oil is supplied to the rear needle bearing of the drive shaft and the rear tapered-roller bearing of the pinion shaft using an oil drip pan (1) and oil bores (2) in the transmission case. Furthermore, the loose gearwheels for 3rd and 4th gear are supplied with oil via the hollowed drive shaft. A relief bore in the drive shaft ensures that the oil can flow freely. Note! The transmission should be filled and topped off with the transmission oil - Burmah TAF 21* only. The oil should be changed every 90,000 miles. * (Available through the Porsche Parts Department) Notes: Drivetrain Repair Sports Cars Page 2.3

14 Boxster (986) Transmission G86.00 Transmission Ratio Z1 Z2 iz ia itot V1000 V6000 Z2:Z1 iz:ia km/h km/h 1st Gear nd Gear rd Gear th Gear th Gear Z1 = Number of teeth in 1st gearwheel in power flow of corresponding gear Z2 = Number of teeth in 2nd gearwheel in power flow of corresponding gear iz = Transmission ratio ia = Final drive ratio V1000 = Calculated vehicle speed at 1,000 rpm engine speed V6000 = Calculated vehicle speed at 6,000 rpm engine speed With 225/50 ZR 16 rear tires, rolling circumference 1,930 mm, (rdyn % - 2.5%) Note: The values in the transmission diagram are indicative and are based on a mean effective rolling radius. Slight deviations due to the tolerance of the tires, change of rolling radius, wear, and slip of tires have not been taken into consideration. G86.01 Transmission Ratio Z1 Z2 iz ia itot V1000 V6500 Z2:Z1 iz:ia km/h km/h 1st Gear nd Gear rd Gear th Gear th Gear Z1 = Number of teeth in 1st gearwheel in power flow of corresponding gear Z2 = Number of teeth in 2nd gearwheel in power flow of corresponding gear iz = Transmission ratio ia = Final drive ratio V1000 = Calculated vehicle speed at 1,000 rpm engine speed V6500 = Calculated vehicle speed at 6,500 rpm engine speed With 255/40 ZR 17 rear tires, rolling circumference 1,948 mm, (rdyn % - 2.5%) Note: The values in the transmission diagram are indicative and are based on a mean effective rolling radius. Slight deviations due to the tolerance of the tires, change of rolling radius, wear, and slip of tires have not been taken into consideration. Transmission Ratios Boxster G86.00 Transmission Ratios Boxster G86.01 Gear Versus Road Speed Graph Page 2.4 Gear Versus Road Speed Graph Drivetrain Repair Sports Cars

15 Boxster (986) Transmission G86.00 Synchronizer 3rd - 5th & Rev. Boxster (986) G86.00/01 Shifting Boxster (986) Synchronizer 3rd to 5th & Reverse Components The effective diameter of the synchronizing rings is 84 mm for the 3rd to 5th and reverse gears. The synchronizing rings for 4th and 5th gear are made of brass. The 3rd and reverse gears also have a molybdenum coating. G86.00/01 Gear Shifter Boxster The Boxster has a cable shift in order to disengage the shift bracket from the gearbox (noise transmission) and to ensure precise shifting behavior when the assembly moves. Internal Transmission Shifting Components The internal shifting system comprises: An inner shifting shaft (1) A deflection shaft (2) with locking device for the reverse gear and shifting cams (7), which prevent 2 gears from being selected at the same time. Two shift rods with a swinging shift fork and two aluminum shift forks. The shift fork for the 1st and 2nd gear (5) is mounted on the shift rod for the 5th and reverse gear (6). A central gear arrester (3). A reverse-gear lock (4). 5-speed Shift Pattern Instead of the usual gear-shift linkage, the cable shift has a selector and shift cable. The cables to which tension and pressure can be applied form the link between the shift lever and the transmission. The five forward gears and the reverse gear are arranged into three shift rows, Functional Description When in its parked position, the inner shift shaft (1) is in the 3rd/4th gear position. It transmits rotary and axial motion to the deflection shaft (2). This slides the appropriate shift rod for the selected gear. The central gear arrester (3) ensures that the individual gears are fixed in the precise position. The reverse-gear lock (4) prevents shifting from the 5th gear into the reverse gear. The double-shift cams (7) on the deflection shaft (2) prevent two gears from being selected at the same time. Drivetrain Repair Sports Cars Page 2.5

16 Boxster (986) Transmission G86.00/01 Reverse-gear Lock Boxster (986) Functional Description The reverse gear lock prevents shifting from the 5th gear into the reverse gear. It is installed as a complete assembly and does not have to be adjusted. Reverse-gear Lock Functional Description If the driver attempts to shift from the 5th gear into the reverse gear, the stop (2) of the deflection shaft (3) hits the blocker (4) of the reverse-gear lock thus preventing shifting into the reverse gear. The reverse gear can only be engaged from the idle position. If the catch plate (1) is moved left out of its idle position by the deflection shaft (2), the lower roller leaves the catch and enters the highest point of the curved path (3). The deformation spring (4) expands. The pretensioning force on the curved paths is increased via the rollers (5) and the catch plate snaps into the selected position. Apart from locking, this snapping effect also provides shift-force support. The spring force then presses the blocker for the reversegear lock into the housing by the axial motion of the deflection shaft. The path of the shift finger into the shift rod for the reverse gear is thus released. G86.00/01 Central Gear Detent Boxster (986) The central gear arrester is installed as a complete assembly. No adjustment is necessary and no measures have been taken to enable the device to be repaired. If the catch plate moves to the right out of its idle position, the same functional procedure applies, but instead the 2nd, 4th, or reverse gears are locked in. Notes: To detent ranges can be selected from the idle position. Detent range for gears 1, 3, 5 Detent range for gears 2,4, R Page 2.6 Drivetrain Repair Sports Cars

17 Boxster/Cayman (987) Transmission Subject Page General Information Boxster/Cayman Transmission Dual-mass Flywheel Drivetrain Repair Sports Cars Page 3.1

18 Boxster/Cayman (987) Transmission Transmissions General This section will only cover the Boxster/Cayman G speed transmission. Manual Transmission G87.01 Boxster/Cayman (987) The Boxster/Cayman (987) feature a revised 5-speed manual transmission, type G87.01 as standard. The following additional options are available: - 6-speed manual transmission, type G87.20, - 5-speed Tiptronic S transmission, Boxster (987) type A87.01, - 5-speed Tiptronic S transmission, 2007 Boxster/Cayman (987) type A87.02, Dual-mass Flywheel The working cycles and ignition sequence of the engine result in speed fluctuations which induce torsional vibration throughout the drivetrain. These torsional vibrations can induce rattling, chattering or floating in all loose parts subject to play which are not incorporated into the power flux (loose gearwheels, synchronization parts). This may lead to unpleasant noise, particularly at low engine speeds combined with high transmission oil temperatures. Similar to previous Porsche vehicles, the Boxster/S and Cayman/S (987) incorporate a dual-mass flywheel (DMF) to prevent such noise. Clutch The Boxster/S (987) and Cayman/S (987) feature a hydraulically actuated single plate dry clutch unchanged from the previous Boxster/S (986), with a pressure plate in nodular cast iron GGG 60 and a clutch disk diameter of 240 mm. The contact pressure has been adapted to the engine torque and the hub of the clutch disk has been adapted to the new transmission input shaft. Manual Transmission G87.01 Boxster/Cayman (987) 5-Speed Transmission Ratio G87.01 The rear axle transmission ratio has been adapted to compensate for the 5 % larger rolling circumference of the rear wheels and now stands at This transmission ratio results in a sporty setup for the Boxster/Cayman and enables high performance with optimum exploitation of the engine torque and the maximum output. Notes: Page 3.2 Drivetrain Repair Sports Cars

19 911 Turbo (996) Transmission Subject Page General Information Dual-mass Flywheel Clutch Ventilation Transmission Cutout Hydraulic Assist Clutch Operation Turbo (996) Gear Ratio Gearshift Mechanism Gears Lubrication Synchronization Final Drive Shifter Shift Forks Shifter Interlock Transmission Housing Viscous Coupling Front Differential Drivetrain Repair Sports Cars Page 4.1

20 911 Turbo (996) Transmission Transmissions Transmission G Turbo (996) General The 911 Turbo (996) came equipped with a six-speed manual transmission or optional Tiptronic automatic transmission used in the new 911 Turbo (996) is an evolution of the transmission from Turbo (993) G To adapt the transmission to the new vehicle, all of the housing components have been redesigned and the gearshift mechanism converted to cable operation. The major changes are as follows: Viscous clutch relocated to front-axle final drive (as with 911 Carrera 4) New transmission shaft mounting New differential New transmission ratios with stronger and quieter running gear sets Note! The Porsche Stability Management system (PSM) is standard equipment on the new 911 Turbo (996). As a mechanical locking differential would have an adverse effect on the PSM system, the 911 Turbo (996) cannot be equipped with a locking differential. Manual Transmission Types: 911 Turbo (996) G96.50 World-Wide on Tiptronic Transmission Type: 911 Turbo (996) A96.50 World-Wide on Basic Tiptronic servicing and diagnosis is covered in a seperate section. The pinion shaft has been lengthened for the fourwheel drive configuration. The pinion passes through the front transmission case and drives the front axle via a singlepiece drive shaft. The frontaxle final drive is identical to that used in the 911 Carrera 4. Dual-Mass Flywheel/Clutch The working cycles and the firing order of the engine cause speed fluctuations resulting in torsional vibrations along the drive train. These torsional vibrations may cause loose (nondriven) gear sets and parts of the synchronizers to rattle, chatter or bounce. This can result in annoying transmission noise, especially at low engine speeds and high transmission oil temperatures. To prevent these noises, the 911 Turbo (996) has a two-mass flywheel (TMF). Clutch Ventilation Clutch ventilation is used in the 911 Turbo (996). Radial vanes arranged on the back of the clutch pressure plate act as a blower when the engine is running. Design The clutch bell housing is completely sealed except for an inlet opening and an air extractor flange. Fresh air is drawn in via the inlet opening and flows through the pressure plate radially for cooling of the clutch friction surfaces. The exhaust air is expelled through the air extractor flange integrated in the clutch housing. This clutch ventilation design reduces the temperature in the clutch bell housing, resulting in less clutch wear and a longer clutch service life. Page 4.2 Drivetrain Repair Sports Cars

21 911 Turbo (996) Transmission G96.50 Transmission Cutout Notes: Drivetrain Repair Sports Cars Page 4.3

22 911 Turbo (996) Transmission Power-Assisted Clutch The 911 Turbo (996) is equipped with a power assisted hydraulic clutch. Design Transmission Ratios 911 Turbo (996) G96.50 The relatively short 1st gear reduces the load on the clutch when starting off and makes for comfortable driving at crawling speeds. 6th gear has been configured to allow maximum vehicle speed to be reached. A tandem power steering pump is used to provide the pressure for the power-assisted clutch. The pressure is generated in the second circuit of the pump and is limited to approx. 80 bar. The accumulator (7) is filled via a pressure limiting valve (3), which is located in the expansion tank. The power-assist servo unit consists of the accumulator (7), poppet valve (8), power valve (9), and slave cylinder (10). The fluid reservoir for the clutch master cylinder is located in the fresh-air chamber (in front of the luggage compartment). The system is filled with Pentosin hydraulic fluid. Note! The threads of the caps for the windshield washing fluid reservoir (blue), brake fluid reservoir (black/yellow) and Pentosin fluid reservoir (green) are identical. The caps could be mixed up by mistake. Gear Versus Road Speed Graph Gearshift Mechanism Gearshift Mechanism Cutout Power-assisted hydraulic clutch components. 1 - Tandem pump 2 - Non-return valve 3 - Pressure limiting valve 4 - Expansion tank for servo pump 5 - Fluid reservoir for clutch master cylinder 6 - Master cylinder 7 - Accumulator 8 - Poppet valve 9 - Power valve 10 - Slave cylinder Page Right angle drive 2 - Cam plate 3 - Retaining spring 4 - Lockout pins 5 - Detent (main shift rod) 6 - Shift fork, 3rd/4th gear 7 - Shift fork, 5th/6th gear 8 - Reverse light switch 9 - Shift fork, R gear 10 - Shift fork, 1st/2nd gear 11 - Main shift rod 12 - Detent Drivetrain Repair Sports Cars

23 911 Turbo (996) Transmission G96.50 Transmission Ratio 911 Turbo (996) Z1 Z2 iz ia itot V1000 V6500 Z2:Z1 iz:ia km/h km/h 1st Gear nd Gear rd Gear th Gear th Gear th Gear Rev. Gear Z1 = Number of teeth in 1st gearwheel in power flow of corresponding gear Z2 = Number of teeth in 2nd gearwheel in power flow of corresponding gear iz = Transmission ratio ia = Final drive ratio V1000 = Calculated vehicle speed at 1,000 rpm engine speed V6500 = Calculated vehicle speed at 6,500 rpm engine speed With 295/30 ZR 18 rear tires, rolling circumference 1,998 mm, (rdyn % - 2.5%) Note: The values in the transmission diagram are indicative and are based on a mean effective rolling radius. Slight deviations due to the tolerance of the tires, change of rolling radius, wear, and slip of tires have not been taken into consideration. Gear Sets Oil Supply To Bearings For 1st/2nd/5th & 6th Gear The two-shaft transmission uses an overhead input shaft and hypoid final drive assembly. The loose (non-driven) and fixed gears have been ground and honed to minimize noise. Pairing of the gears was not necessary (hence no pairing number). All loose gears have needle roller bearings. The fixed gears for 1st and 2nd gear are part of the input shaft and are therefore not separately replaceable parts. Reverse gear is synchronized and can be engaged even when the vehicle is coasting slowly forwards. The reverse gear is located in the front transmission case. The intermediate gear for reverse is mounted on a shaft via needle roller bearings and is secured with a circlip. The shaft is locked in place by a bolt mounted through the transmission case. 5th and 6th gears are also in the front transmission case. The fixed gears are attached to the input shaft and the loose gears are mounted on the pinion shaft. Oil Drip Pan Location The bearings for loose gears 1, 2, 5 and 6 are lubricated as follows: The rotation of the crown wheel (ring gear) transfers oil from the oil sump into an oil collector (1) attached to the transmission case. From there, the oil is fed directly to the hollow pinion shaft via a connecting pipe (2). The rotation of the pinion shaft causes the oil to be supplied directly to the 1st, 2nd, 5th, and 6th loose gears via cross bores. Drivetrain Repair Sports Cars Page 4.5

24 911 Turbo (996) Transmission When the guide sleeve of the 1st and 2nd gears is fitted, care must be taken to ensure that gaps between the teeth of the internal gearing are aligned with the oil bores. Oil Supply To Bearings For 3rd And 4th Gear Since the oil change interval is specified at every 90,000 miles, it is essential that only the approved oil types are used. Synchronization, 1st/2nd Gear As with the previous transmission, the G96.50 transmissions use double cone synchronization for 1st and 2nd gears. This synchronization reduces shifting forces by as much as 30 40% compared to single cone synchronization. Functional Description Location of Oil Hole in Hollow Drive Shaft The rotation of the loose gears in the front transmission case transfers oil from the oil sump to an oil collector (1) integrated in the transmission case. From there, the oil is fed to the hollow input shaft. The rotation of the input shaft causes the oil to be supplied directly to the loose gears of the 3rd and 4th gear via cross bores. This oil supply to the bearings allows uniform oil distribution, lubrication at critical locations, reduced cavitational losses and lower oil temperatures. The required quantity of oil and the approved oil types are given in the Technical Manual and Warranty & Maintenance Manual. Note! The lower section of the gear case is sealed to prevent the oil from flowing out of the front transmission case as a result of extreme acceleration. When filling the transmission with oil, it is critical that the specified filling capacity is observed to ensure that all oil chambers are properly filled. Synchronizer Components The synchronizing ring (2), friction ring (3), guide sleeve (4) and shift sleeve (5), rotate at the same speed as the pinion shaft (vehicle speed). The loose gear with clutch body (6) and the tapered ring (1) rotate at the same speed as the engine. When the shift sleeve is moved towards the guide sleeve, friction is produced between the synchronizing ring and tapered ring outer surface and between the friction ring and tapered ring inner surface. This friction decelerates (1 2 shifting) or accelerates (2 1 shifting) the parts rotating at engine speed. Doubling the friction surfaces considerably reduces shifting forces. Synchronization, 3rd 6th And Reverse Gear Synchronization for gears 3 through 6 and for the reverse gear utilizes single cone synchronization. The synchronizing rings for gears 3 through 6 are identical and have a molybdenum coating. The synchronizing ring for reverse gear is not coated. Page 4.6 Drivetrain Repair Sports Cars

25 911 Turbo (996) Transmission Gear Retention To retain the gears in position once a gear is selected, the loose gear (clutch body) gear teeth and the shift sleeve gear teeth are bevelled. When the torque is transmitted, the bevelled surfaces are pressed against each other and drawn together. Stepped elevations on the clutch bodies prevent overshifting. Shift Sleeves The shift sleeves for 1st/2nd gears and 3rd/4th gears are asymmetrical. During assembly, it is important to ensure that the groove (A) face 2nd gear and 3rd gear, respectively. 1 - Shift sleeve 2 - Ball bearing 3 - Driver dog 4 - Spring A - Groove B - Punch mark C - 2nd gear side D - 1st gear side 1st/2nd gear shift sleeve assembly. 3rd/4th gear shift sleeve assembly is identical. Final Drive The final drive gear set is a hypoid drive. This means that the center line of the ring gear is 10 mm above the center line of the pinion shaft. Hypoid drives can (with the same ring gear size) transmit relatively high torques since the teeth of the pinion shaft are designed to be more robust. Shift sleeve showing continuous groove (A) that must face 2nd gear (1st/2nd shift sleeve) and 3rd gear (3rd/4th gear shift sleeve) during assembly. The shift sleeves have three grooves in the inner gearing, indicated by three punch marks (B) on the sleeve. When mounting the shift sleeves to the guide sleeves, the punch marks (B) must be aligned with the ball bearings (2). In addition, the new position of the ring permits lower diffraction angles along the drive shafts. The pinion shaft and ring gear are manufactured using the Gleason method. The pinion shaft is hollow-drilled to optimize lubrication and to reduce weight. Recesses have been forged into the back of the ring gear to reduce weight. The adjusting dimension E (pinion depth) is 70 mm and is set at the tensioning plate and four-point bearing using adjusting shims. Notes: Drivetrain Repair Sports Cars Page 4.7

26 911 Turbo (996) Transmission Transmission Shaft Mounting Functional Description The input and output shafts are each supported by four bearings. In the transmission case, the two shafts are each mounted on one roller bearing. Four-point bearings, which are fitted in a tensioning plate, are used as axial mounts. There is also an additional roller bearing for each shaft in the gear case and in the front transmission case. Gear Shifting Selector Lever The selector cable is connected to the selector lever shaft (1) to allow preselection of the gear plane (shift gate). Side to side movement of the shift lever is converted into rotary movement via a right-angle drive (2). This causes the internal shift rod (3) and the internal shift finger attached to the rod to rotate. As a result, the internal shift finger engages in the corresponding shift rod and the gear plane is preselected. The gear planes are arrested with a springloaded cam plate. 6-Speed Shift Pattern The six forward gears and the reverse gear (R) are arranged in four shift gates. 6th gear is located at the bottom right of the shift pattern. A cable shift mechanism is used. This prevents assembly movements and vibrations from being transmitted to the gear-shift lever. Two cables form the connection between the gearshift lever and the transmission. The advantages of this cable system are small space requirements, low weight, and effective isolation of movements and vibrations through the gearshift lever without impairing shifting precision. The shift cable is connected to the external shift lever (5) to allow the gear to be engaged. The external shift lever is, in turn, connected to an internal shift gate (6) which engages in a selector shaft attached to the internal shift rod which causes the respective shift fork to be moved. Page 4.8 Drivetrain Repair Sports Cars

27 911 Turbo (996) Transmission Shift Forks The aluminum-alloy shift forks for 1st/2nd gears 3rd/4th gears are fixed to the shift rods by rolled pins and are not adjustable. The shift forks for 5th/6th gears and reverse are attached to the shift rods using clamping bolts and are adjustable. The surface of the shift rods are knurled to help retain the shift forks in their adjusted position. Shift Interlock Lock out pins are attached to the tensioning plate and the shift rods to ensure that only one gear can be engaged at any one time. During assembly and disassembly, it is important to ensure that these pins are positioned correctly. Gear Detent A neutral gear position detent is provided by the internal mechanism. Individual shift rod travel is also limited by separate springs and balls. Cross Section Of Transmission Showing Shift Rod Lockout Pins Transmission Case Internal Shift Mechanism Showing Shift Rod Spring And Ball Detents The transmission consists of three sections the clutch housing, gear case and front transmission case. The sections are die-cast and made of a light alloy. The individual sections are sealed using Loctite 574 without paper gaskets. The case sections are aligned with locating pins and bolted together with M8 bolts. The reverse light switch is located in the front transmission case. A steel insert is cast into the bearing bores to minimize bearing clearance on the input and output shaft when the clutch housing expands due to heat. Notes: Drivetrain Repair Sports Cars Page 4.9

28 911 Turbo (996) Transmission Viscous Clutch The 911 Turbo (996) has a multi-disc viscous clutch, specifically adapted to the specific 911 Turbo characteristics. This has meant a further improvement in traction. The inner splines have been changed to prevent interchangeability with other clutch drives. To reduce temperatures at the multi-disc viscous clutch, the unit has been integrated in the front-axle final drive. No additional space in the manual or Tiptronic transmission had to be provided as a result of this measure. The viscous clutch is filled with a precise quantity of high-viscosity silicon oil and is permanently sealed. It is not possible to add more silicon oil or to check the oil level. Functional Description slippage at the front and rear wheels and on the resulting speed differential at the viscous clutch, a variable torque distribution exists. In other words, the distribution adapts to the traction requirements. However, since tire slippage exists whenever drive torque is transmitted, it is possible to obtain a permanent fourwheel drive system with variable torque distribution of approx. 5 to 40% to the front axle. Front Axle Differential (Z96/00) The front axle is driven by a spiral bevel gear, which is ground and lapped to eliminate production tolerances. To reduce drag losses, grooved ball bearings (1) are used in the differential gear instead of tapered roller bearings. A hole with M8 thread (2) is drilled into the side cover of the differential. This is used for noise measurements during production and can be disregarded by service personnel. There is a bleeder hole (3) in the underside of the longneck tube. This hole should not be sealed. The discharge of transmission oil from this hole is an indication that the sealing ring (4) is damaged. Viscous Clutch The multi-disc viscous clutch housing (1) is connected to the pinion shaft of the front-axle final drive. The clutch hub (2) is connected to the central drive shaft and is supported by plain bearings. If there is a speed differential between the outer and inner discs, a torque is transmitted from the fast to the slow rotating side through the internal fluid friction. The discs are fully separated by the oil so that they are not subject to abrasion or wear. Since traction distribution is dependent on the difference between the traction Note! Performance tests should only be carried out on a fourroller test stand (dynamometer) with engine speed decoupling. If testing is performed on a two roller test stand, the drive shaft must first be removed. 1 - Grooved ball bearings 2 - Test (acoustic) access hole (M8 thread) 3 - Bleeder hole 4 - Sealing ring Page 4.10 Drivetrain Repair Sports Cars

29 911 GT2/GT3 Transmission Subject Page General Information Dual-mass Flywheel Pressure Plate Transmission Cutout GT2/GT3 Gear Ratios Clutch Ventilation Gearshift Mechanism Synchronization Final Drive Lubrication Transmission Cooling Shifter Shift Forks Shifter Interlock Transmission Housing Limited-slip Differential Drivetrain Repair Sports Cars Page 5.1

30 911 GT2/GT3 Transmission Transmissions General Manual Transmission 911 GT3 (997) The new 911 GT3 (997) is only available with a manual 6-speed gearbox without hydraulic clutch assistance. The gearbox has been modified in order to improve the acceleration capability and to adapt it to the torque curve. Key features: General Manual Transmission 911 GT2/GT3 (996) The GT3 (996) 6-speed transmission is based on the GT2 (996) 6-speed manual transmission. Both transmission types share components specially designed for these two endurances tested 911 vehicles. Key features: Dual-mass flywheel Cable gearshift with direct translation of shift actuation through shortening of lever ratio on the gearbox input lever Transmission oil cooling through a transmission mounted oil-to-water heat exchanger Oil-spray lubrication with pressurized oil supply through an additional oil pump Asymmetric limited-slip differential Use of steel synchronizing rings Manual Transmission Types: 911 GT2 (996) G GT3 (996) G GT3 RS (996) G96.90 RoW Cable shifting system with direct gearshift through a short lever ratio on the gearbox input lever. Oil spray lubrication using pressure oil supplied by the oil pump. Transmission oil cooling using a heat exchanger to ensure stability even under extreme loads. Steel synchronization rings for gears 3 to 5. Shorter transmission ratios compared to the 911 GT3 (996). Double-mass flywheel. Manual Transmission Type: 911 GT3 (997) G Dual-Mass Flywheel/Clutch The working cycles and the firing order of the engine cause speed fluctuations resulting in torsional vibrations along the drive train. These torsional vibrations may cause loose (nondriven) gear sets and parts of the synchronizers to rattle, chatter or bounce. This can result in annoying transmission noise, especially at low engine speeds and high transmission oil temperatures. To prevent these noises, 911 GT2/GT3 (996) & 911 GT3 (997) use a dualmass flywheel (TMF). The GT3 RS uses a singlemass flywheel. Pressure Plate The 911 Turbo (996) pressure plate is used on both 911 GT2/GT3 models. Page 5.2 Drivetrain Repair Sports Cars

31 911 GT2/GT3 Transmission G96.88/96 Transmission Cutout Notes: Drivetrain Repair Sports Cars Page 5.3

32 911 GT2/GT3 Transmission G96.88 Transmission Ratio 911 GT2 (996) Z1 Z2 iz ia itot V1000 V6500 Z2:Z1 iz:ia km/h km/h 1st Gear nd Gear rd Gear th Gear th Gear th Gear Rev. Gear Z1 = Number of teeth in 1st gearwheel in power flow of corresponding gear Z2 = Number of teeth in 2nd gearwheel in power flow of corresponding gear iz = Transmission ratio ia = Final drive ratio V1000 = Calculated vehicle speed at 1,000 rpm engine speed V6500 = Calculated vehicle speed at 6,500 rpm engine speed With 315/30 ZR 18 rear tires, rolling circumference 1,971 mm, (rdyn % - 2.5%) Note: The values in the transmission diagram are indicative and are based on a mean effective rolling radius. Slight deviations due to the tolerance of the tires, change of rolling radius, wear, and slip of tires have not been taken into consideration. G96.96 Transmission Ratio 911 GT3 (996) Z1 Z2 iz ia itot V1000 V7500 Z2:Z1 iz:ia km/h km/h 1st Gear nd Gear rd Gear th Gear th Gear th Gear Z1 = Number of teeth in 1st gearwheel in power flow of corresponding gear Z2 = Number of teeth in 2nd gearwheel in power flow of corresponding gear iz = Transmission ratio ia = Final drive ratio V1000 = Calculated vehicle speed at 1,000 rpm engine speed V7500 = Calculated vehicle speed at 7,500 rpm engine speed With 295/30 ZR 18 rear tires, rolling circumference 1,934 mm, (rdyn % - 2.5%) Note: The values in the transmission diagram are indicative and are based on a mean effective rolling radius. Slight deviations due to the tolerance of the tires, change of rolling radius, wear, and slip of tires have not been taken into consideration. G97.90 Transmission Ratio 911 GT3 (997) Z1 Z2 iz ia itot V1000 V8000 Z2 : Z1 9/31 km/h km/h 1st gear nd gear th gear th gear th gear th gear Rev. gear Z1 = Number of teeth in 1st gearwheel in power flow of corresponding gear Z2 = Number of teeth in 2nd gearwheel in power flow of corresponding gear iz = Transmission ratio ia = Final drive ratio V1000 = Calculated vehicle speed at 1,000 rpm engine speed V7500 = Calculated vehicle speed at 8,000 rpm engine speed With 305/30 ZR 19 rear tires, rolling circumference 2091 mm) Note: The values in the transmission diagram are indicative and are based on a mean effective rolling radius. Slight deviations due to the tolerance of the tires, change of rolling radius, wear, and slip of tires have not been taken into consideration. Page 5.4 Drivetrain Repair Sports Cars

33 911 GT2/GT3 Transmission Transmission Ratios 911 GT2 (996) G96.88 On level roads, it is advisable to start off in 2nd gear. In 2nd gear the vehicle can also be driven away more smoothly on slippery road surfaces. The 6th gear has been configured to allow the maximum possible vehicle speed to be reached. The exhaust air is expelled through the air extractor flange integrated in the clutch housing. This clutch ventilation design reduces the temperature in the clutch bell housing, resulting in less clutch wear and a longer clutch service life. Gearshift Mechanism 911 GT2/GT3 (996) Gear Versus Road Speed Graph Transmission Ratios 911 GT3 (996) G96.96 The relatively short first gear is easier on the clutch and the 6th gear has been configured to allow the maximum possible vehicle speed to be reached. Gearshift Mechanism Cutout 1 - Right angle drive 2 - Cam plate 3 - Retaining spring 4 - Lockout pins 5 - Detent (main shift rod) 6 - Shift fork, 3rd/4th gear 7 - Shift fork, 5th/6th gear 8 - Reverse light switch 9 - Shift fork, R gear 10 - Shift fork, 1st/2nd gear 11 - Main shift rod 12 - Detent Gearshift Mechanism 911 GT3 (997) Gear Versus Road Speed Graph Clutch Ventilation Clutch ventilation is used in the 911 GT2/GT3 models. Radial vanes arranged on the back of the clutch pressure plate act as a blower when the engine is running. For high shift dynamics with short shift throws, the new 911 GT3 (997) has the shift block of the current 911 Carrera (997) generation with a shorter shift lever ratio and a GT3 specific short lever ratio on the gearbox input lever. As a result, the entire shift ratio of the new 911 GT3 is approx. 15% shorter than in the 911 GT3 (996) and approx. 33% shorter than in the current 911 generation. Design The clutch bell housing is completely sealed except for an inlet opening and an air extractor flange. Fresh air is drawn in via the inlet opening and flows through the pressure plate radially for cooling of the clutch friction surfaces. Drivetrain Repair Sports Cars Page 5.5

34 911 GT2/GT3 Transmission Gear Sets Functional Description The two-shaft transmission uses an overhead input shaft and hypoid final drive assembly. The loose (non-driven) and fixed gears have been ground and honed to minimize noise. Pairing of the gears was not necessary (hence no pairing number). All loose gears have needle roller bearings. The fixed gears for 1st and 2nd gear are part of the input shaft and are therefore not separately replaceable parts. Reverse gear is synchronized and can be engaged even when the vehicle is coasting slowly forwards. The reverse gear is located in the front transmission case. The intermediate gear for reverse is mounted on a shaft via needle roller bearings and is secured with a circlip. The shaft is locked in place by a bolt mounted through the transmission case. 5th and 6th gears are also in the front transmission case. The fixed gears are attached to the input shaft and the loose gears are mounted on the pinion shaft. Gear Sets 911 GT3 (997) To improve the ability of the new 911 GT3 (997) to accelerate and to adapt the gear-box to the torque curve, the ratios of gears 2 to 6 were shortened. This was enabled through the advanced high-revving concept of the engine, and offers even better power transmission with increased maximum speed and shift speed when accelerating after changing gear. Synchronization, 1st/2nd Gear As with the previous transmissions, the transmissions use double cone synchronization for 1st and 2nd gears. This synchronization reduces shifting forces by as much as 30 40% compared to single cone synchronization. Synchronizer Components The synchronizing ring (2), friction ring (3), guide sleeve (4) and shift sleeve (5), rotate at the same speed as the pinion shaft (vehicle speed). The loose gear with clutch body (6) and the tapered ring (1) rotate at the same speed as the engine. When the shift sleeve is moved towards the guide sleeve, friction is produced between the synchronizing ring and tapered ring outer surface and between the friction ring and tapered ring inner surface. This friction decelerates (1 2 shifting) or accelerates (2 1 shifting) the parts rotating at engine speed. Doubling the friction surfaces considerably reduces shifting forces. Synchronization, 3rd 6th And Reverse Gear The synchronization mechanism used for gears 3-6 and for the R gear is a single cone synchronization mechanism. The synchronizing rings for gears 3-5 are made of steel. The synchronizing rings for the 6th and reverse gear are made of special bronze. The friction surfaces of all synchronizing rings (except the synchronizing ring for the reverse gear) have a molybdenum coating. Gear Retention To retain the gears in position once a gear is selected, the loose gear (clutch body) gear teeth and the shift sleeve gear teeth are bevelled. When the torque is transmitted, the bevelled surfaces are pressed against each other and drawn together. Stepped elevations on the clutch bodies prevent overshifting. Page 5.6 Drivetrain Repair Sports Cars

35 911 GT2/GT3 Transmission Shift Sleeves The shift sleeves for 1st/2nd gears and 3rd/4th gears are asymmetrical. During assembly, it is important to ensure that the groove (A) face 2nd gear and 3rd gear, respectively. The shift sleeves have three grooves in the inner gearing, indicated by three punch marks (B) on the sleeve. When mounting the shift sleeves to the guide sleeves, the punch marks (B) must be aligned with the ball bearings (2). Shift sleeve showing continuous groove (A) that must face 2nd gear (1st/2nd shift sleeve) and 3rd gear (3rd/4th gear shift sleeve) during assembly. 1 - Shift sleeve 2 - Ball bearing 3 - Driver dog 4 - Spring A - Groove B - Punch mark C - 2nd gear side D - 1st gear side 1st/2nd gear shift sleeve assembly. 3rd/4th gear shift sleeve assembly is identical. Notes: Drivetrain Repair Sports Cars Page 5.7

36 911 GT2/GT3 Transmission Final Drive The final drive gear set is a hypoid drive. This means that the center line of the ring gear is 10 mm above the center line of the pinion shaft. Hypoid drives can (with the same ring gear size) transmit relatively high torques since the teeth of the pinion shaft are designed to be more robust. In addition, the new position of the ring permits lower diffraction angles along the drive shafts. The pinion shaft and ring gear are manufactured using the Gleason method. The pinion shaft is hollow-drilled to optimize lubrication and to reduce weight. Recesses have been forged into the back of the ring gear to reduce weight. The adjusting dimension E (pinion depth) is 70 mm and is set at the tensioning plate and four-point bearing using adjusting shims. Transmission Shaft Mounting The input and output shafts are each supported by four bearings. In the transmission case, the two shafts are each mounted on one roller bearing. Four-point bearings, which are fitted in a tensioning plate, are used as axial mounts. There is also an additional roller bearing for each shaft in the gear case and in the front transmission case. A separate oil pump (1) is used in transmission to ensure optimum lubrication even at critical locations, uniform oil distribution, reduced churning losses and a drop in transmission oil temperature. The gear pump (1) driven by a drive pinion mounted on the drive shaft draws the oil out of the differential housing. It pumps the oil through the oil to water heat exchanger (2) and then feeds it to the various lubricating points. The differential housing is divided into two sections by a partition wall to ensure that the oil can be drawn in reliably without air pockets. One section contains the crown wheel and the other the settled oil and the suction pipe (3). In the front transmission cover, the cooled transmission oil is pumped into the transmission (4) and passes through the hollow drilled input and output shaft to lubricate the loose gear bearings. The shafts have cross bores at the loose gear bearings. This ensures that oil is supplied directly to the loose gear bearings. An oil spray pipe (5) also supplies oil to the 3rd - 6th gear mesh as well as to the bevel gear and crown wheel. The oil pump has a delivery rate of approx. 8 liters at 6,000 rpm. The oil pressure is limited to bar by means of a ball valve. Transmission Cooling Transmission Lubrication Transmission Cooling Components 911 GT2/GT3 Transmission Lubrication and Cooling Components An oil to water heat exchanger (1) serving as a transmission oil cooler is mounted to the transmission in order to prevent excessive transmission oil temperatures, especially when the vehicle is used for racing. This ensures that the oil temperature does not exceed 248 F. (120 C.), even under extreme conditions. A coolant shut-off valve (2) is fitted since the oil-to-water heat exchanger is only used for cooling and not for heating the transmission oil. Page 5.8 Drivetrain Repair Sports Cars

37 911 GT2/GT3 Transmission The DME control unit is informed of the transmission oil temperature by means of a temperature sensor (3) (fitted to the oil-to-water heat exchanger bracket). If the temperature is higher than 221 F. (105 C.), the shut-off valve is opened, the heat exchanger is flushed with coolant and the transmission oil is cooled. The transmission oil cooling system is deactivated again at 203 F. (95 C.). Functional Description Note! It is essential to observe the change intervals, filling capacities and the approved oil types specified in the Technical Manual and the Warranty & Maintenance Manual. Gear Shifting Selector Lever The selector cable is connected to the selector lever shaft (1) to allow preselection of the gear plane (shift gate). Side to side movement of the shift lever is converted into rotary movement via a right-angle drive (2). This causes the internal shift rod (3) and the internal shift finger attached to the rod to rotate. As a result, the internal shift finger engages in the corresponding shift rod and the gear plane is preselected. The gear planes are arrested with a springloaded cam plate. 6-Speed Shift Pattern The six forward gears and the reverse gear (R) are arranged in four shift gates. 6th gear is located at the bottom right of the shift pattern. A cable shift mechanism is used. This prevents assembly movements and vibrations from being transmitted to the gear-shift lever. Two cables form the connection between the gearshift lever and the transmission. The advantages of this cable system are small space requirements, low weight, and effective isolation of movements and vibrations through the gearshift lever without impairing shifting precision. The shift cable is connected to the external shift lever (5) to allow the gear to be engaged. The external shift lever is, in turn, connected to an internal shift gate (6) which engages in a selector shaft attached to the internal shift rod which causes the respective shift fork to be moved. Drivetrain Repair Sports Cars Page 5.9

38 911 GT2/GT3 Transmission Shift Forks The aluminum-alloy shift forks for 1st/2nd gears 3rd/4th gears are fixed to the shift rods by rolled pins and are not adjustable. The shift forks for 5th/6th gears and reverse are attached to the shift rods using clamping bolts and are adjustable. The surface of the shift rods are knurled to help retain the shift forks in their adjusted position. Gear Detent A neutral gear position detent is provided by the internal mechanism. Individual shift rod travel is also limited by separate springs and balls. Cross Section Of Transmission Showing Shift Rod Lockout Pins Transmission Case The transmission consists of three sections the clutch housing, gear case and front transmission case. The sections are die-cast and made of a light alloy. The individual sections are sealed using Loctite 574 without paper gaskets. The case sections are aligned with locating pins and bolted together with M8 bolts. The reverse light switch is located in the front transmission case. A steel insert is cast into the bearing bores to minimize bearing clearance on the input and output shaft when the clutch housing expands due to heat. Internal Shift Mechanism Showing Shift Rod Spring And Ball Detents Shift Interlock Lock out pins are attached to the tensioning plate and the shift rods to ensure that only one gear can be engaged at any one time. During assembly and disassembly, it is important to ensure that these pins are positioned correctly. Limited-slip Differential Due to its rear-mounted engine and the resulting axle load distribution, the 911 GT2/GT3 are able to convert engine output into forward propulsion very efficiently (good traction) even under poor road conditions (e.g. wet surface), a locking factor of 40% is sufficient in the pull phase. Higher locking factors would have a detrimental effect on the cornering ability of the vehicle without any significant improvement in traction. The locking factor in the push phase is 60%. The value for the push phase is higher than that for the pull phase since the engine drag torque is less than the maximum engine torque. Additionally, this configuration prevents the vehicle from oversteering in the case of load changes in corners. Page 5.10 Drivetrain Repair Sports Cars

39 911 GT2/GT3 Transmission The limited-slip differential was designed as an element of the overall driving dynamics configuration of the 911 GT2/GT3 and should only be regarded as a complete system with respect to the overall characteristics of this vehicle. Functional Description The higher the expansion forces Pax acting in both directions on the friction discs are, the higher the locking force of the multiple-disc limited-slip differential will be. The limited-slip differential is preloaded by the diaphragm springs (6) in both disc sets so that it is ready for operation without torque having to be applied. The static friction moment produced by preloading the disc sets is increased considerably under driving conditions by the expansion force which also acts on the disc sets. In the case of the 911 GT2/GT3, the overrun angles in the push phase are such that a locking value of 60% can be achieved (expansion force Pax + preloading by diaphragm springs). The overrun angles in the pull phase have been configured such that a locking value of 40% can be achieved. Limited-slip Differential 911 GT3 (997) Limited-Slip Differential The housing of the limited-slip differential (1) is driven by the crown wheel of the drive assembly. The pressure pieces (3) and (7) interlock with the housing (1), but can move axially and are shifted to the left and right-hand disc sets by the differential pins (2) when loads are applied. The expansion force generated (Pax) depends on the applied torque, the overrun angles (a) and the pressure pieces (3) and (7). Like the 911 GT3 (996), the new 911 GT3 (997) also comes with an asymmetric limited slip differential as standard. The lock values are 28% under traction and 40% under deceleration. Compared to the previous model (40% traction, 60% deceleration), the values have been slightly changed and tuned to the specific performance of the new 911 GT3 with improved driving dynamics. Notes: Drivetrain Repair Sports Cars Page 5.11

40 911 GT2/GT3 Transmission Page 5.12 Drivetrain Repair Sports Cars

41 Tiptronic Transmission Subject Page General Information Transmission Type A50.01/02/03/04/05, 4-speed Changing ATF Shifter Transmission Type A96.00/30, 5-speed Torque Converter Transmission Operation Control Unit Processes Solenoid Valve Logic ATF Cooling Control Unit Location Transmission Type A96.10/35/50, A97.01/31 5-speed Transmission Operation Control Unit Processes, Type A96.10/35/ Control Unit Processes, Type A97.01/ Torque Converter Valve Body ATF Cooling Control Unit Location Coding and Adaption Transmission Type A86.00/05/20, A87.05/20/21 5-speed ATF Cooling Control Unit Location, Boxster Control Unit Location, Cayman S Drivetrain Repair Sports Cars Page 6.1

42 Tiptronic Transmission Tiptronic Transmissions General A automatic transmission drive system was developed for the 911 Carrera 2 (964) to cater to the wishes of sports car drivers who wanted an alternative to the manual transmission. Porsche Tiptronic, a load-shiftable four speed sport transmission, became available in January, 1990, as an alternative to the conventional five-speed manual transmission. Tiptronic Transmission Types: Boxster (987) A87.02 M.Y Boxster S (987) A87.20 M.Y on Cayman (987) A87.02 M.Y Cayman S (987) A87.21 M.Y Transmission A50.01/02/03/04/05 4-speed 911 Carrera 2 (964) A50.01 RoW/USA/Canada M.Y A50.02 RoW M.Y A50.03 USA/Canada M.Y Carrera 2 (993) A50.04 RoW M.Y A50.05 USA/Canada M.Y Carrera 2 (996) A96.00 RoW/USA/Canada M.Y A96.10 RoW/USA/Canada M.Y Carrera 4/4S (996) A96.30 USA/Canada M.Y, A96.35 USA/Canada M.Y, Tiptronic Transmission Type A Carrera/S (997) A97.01 RoW/USA/Canada M.Y on 911 Carrera 4/4S (997) A97.31 USA/Canada M.Y, 2006-on 911 Turbo (996) A96.50 World-Wide Turbo (997) A97.50 World-Wide 2007 Boxster (986) A86.00 M.Y A86.05 M.Y Tiptronic Transmission Type A 50.02/03/04/05 Boxster S (986) A86.20 M.Y Boxster (987) A87.01 M.Y Page 6.2 Drivetrain Repair Sports Cars

43 Tiptronic Transmission Repairing With the introduction of the Tiptronic transmission on the Carrera 2 (964), repair work on Tiptronic transmission type A50 is limited to: Torque converter Front cover Spur gears, bearings and intermediate plate Valve body ATF Filter, pan and gasket Sensors Differential Repair to the automatic section was not permited and required replacement of complete units. Changing ATF Torque converter and series connected four speed planetary gear with control unit are filled with ATF DEXRON II D known from the eight cylinder automatic transmission program. ATF volume is 9 liters. ATF is cooled by an ATF cooler in the right front wheel house, in front of the engine oil cooler. Checking ATF Level ATF level can be checked on the righthand side of the transmission case next to the ATF sump, as also on automatic transmissions in the four and eight cylinder engine program. Three arrows are located on the semi-trans-parent plastic body from top to bottom. Changes and Modifications In 1992 the transmission front mount was changed. In model year 1996 tuning as well as upshift and downshift points of the transmission were revised to improve engine output, environmental compatibility and comfort. As an additional feature, the transmission electronics were modified to incorporate the OBD II system for the USA market. Major modifications were: Retarded activation of reverse light by approx..05 sec. Coding via PIWIS Tester Modified hydraulic control unit Gear monitoring based on computing of transmission ratio Shift lock control unit deleted Lateral acceleration sensor deleted Fault memory can only be erased with PIWIS Tester Reduced tooth backlash Capacities Fluid capacities and types can be found in each models Owner s Manual, Technical Manual and Technical Information Bulletins. Always refer to these before performing maintenance service. Checking ATF Level Maximum at operating temperature Minimum at operating temperature Level at 68 F. (20 C.) ATF temperature Filling ATF Diagnosis PIWIS Tester is used. ATF DEXRON II D can be filled in very easily through a fastfilling device on the right-hand side of the transmission case (arrow). Drivetrain Repair Sports Cars Page 6.3

44 Tiptronic Transmission Shifter Adapters, which are suitable for all filling systems and depend on the filling hose diameter, are available for fast filling of the transmission. The Porsche Tiptronic is an electronically controlled automatic transmission that may be operated either as an automatic or as a manual transmission. The mode of operation is determined by the control stalks that are set to one of the two operating planes specified. The fast-filling device can be unscrewed for emergency filling, so ATF can be poured in through a bent pipe (arrow). When used as an automatic transmission, the gears are shifted automatically and the correct gear is selected by an intelligent gear selection program. This gear selection program takes additional measured variables into consideration to assess the driving conditions and automatically switch over to the correct gear selection map for the respective driving mode. Further special features such as prevention of unintended power upshifts or shifting up in a curve, a special warming-up program and low slip upshift at low friction coefficients help to improve driving comfort, offer added environmental protection and improve driving safety. In the manual mode, the gears are engaged manually with a yoke. Automatic gear changes are only made at the engine speed limits to protect the engine against overrevving or underrevving. The really important advantage of this drive system is that upshifts as well as downshifts can be operated without changing the position of the accelerator pedal. This is possible because of a selector lever system which has two selection gates. Up-shifts and downshifts take place automatically in the left gate, depending on the position of the selector lever P-R-N-D-3-2-1, just like with a fully automatic transmission. Moving off is accomplished with a hydraulic torque converter, which has a lockup clutch, that remains closed from the second drive range on. Page 6.4 Drivetrain Repair Sports Cars

45 Tiptronic Transmission Shifter (cont d) Automatic shifts can be influenced extraordinarily fast by tipping the selector lever (forward: upshift; back: downshift) after the selector lever is moved toward the right out of D into the second selection gate. Upshifts and downshifts are made without interruption of power flow. Five different shift programs can be called, since a Porsche Tiptronic transmission has an electronic program control. The control unit learns depending on driving habits of a pertinent driver and changes the upshift and downshift program within 45 seconds from, for example, comfort to sport. Approximately 90 seconds are required to change back from sport to comfort to conform with changed driving habits. A warm-up shift program is also introduced after a cold start, in order to have the catalytic converter of the engine reach its operating temperature as quickly as possible. or in a curve the pertinent gear corresponding with the instantaneous lateral acceleration will remain engaged. Values of the throttle valve position, engine speed, lateral acceleration and longitudinal acceleration are determined at intervals in time of 30 or 100 milliseconds. After the determination of mean values there, are the production of modulation factors, which are compared with each other at brief intervals. The actual value calculated in this manner is compared with an ideal shift curve and the transmission is shifted accordingly. Notes: Driving in Left Selection Gate If the selector lever is left in the left selection gate, in D by way of example, an extremely intelligent programmed drive program is activated. In addition to the five drive programs, a Porsche Tiptronic transmission has considerably more sensible and sport car justified reaction than that of all known automatic transmissions. Coasting upshifts before curves and shifts in curves are avoided in the automatic function. Upshift and downshift curves are adapted dynamically or more reserved depending on driver requirements. Performance of the Porsche Tiptronic therefore fulfills all requirements in regards to comfort, reliable operation and sportiness. It is possible to change gears immediately before or even in a curve because of load-dependent shifting, as well as exceptionally short shift travel in case of manual operation. In automatic operation, the shift curve family adaptation is influenced by the accelerator pedal position or throttle valve gap, as well as road speed, longitudinal acceleration, lateral acceleration and engine speed. If a fast traction requirement is reported, e.g. due to fast operation of the accelerator pedal, the shift curve family is corrected in the direction of a higher shift speed, i.e. dynamics, without that kickdown (a function found to be negative quite frequently) has to be used. If the throttle valve is adjusted soft again by the accelerator pedal, the shift curve family will be changed again after a short time in direction of low speed shifting and therefore smoother driving. If the accelerator is released before entering a curve, i.e. the throttle valve is closed quickly, the gear engaged at the time will remain engaged. If the throttle valve is opened again, i.e. the accelerator pedal operated, shifting will again be in accordance with the shift program Drivetrain Repair Sports Cars Page 6.5

46 Tiptronic Transmission Transmission A96.00/30 5-speed Repair to the automatic section was not permited and required replacement of complete units. Capacities Fluid capacities and types can be found in each models Owner s Manual, Technical Manual and Technical Information Bulletins. Always refer to these before performing maintenance service. Diagnosis PIWIS Tester is used. Tiptronic Transmission Type A Carrera 2 (996) Torque Converter The converter comprises the impeller, turbine, stator, and the oil required for torque transmission. The impeller driven by the engine causes the oil in the converter to be pumped in a circular flow. This oil flow reaches the turbine and its flow direction is changed. The oil leaves the turbine at the hub and flows to the stator where its direction is once again changed. The oil is thus supplied to the impeller in the appropriate flow direction. The change in direction creates a lock-up of the stator. The reaction of the fluid increases the turbine speed. The ratio of turbine speed to impeller speed is known as the torque increase. Tiptronic Transmission Type A Carrera 4 (996) As an alternative to the six-speed manual transmission with mechanical disengaging clutch, a power-shifted five-speed sports transmission, Porsche Tiptronic, is also available. The principal advantage of this drive system is that it is possible to shift to a lower and higher gear both automatically and manually without a break in the tractive force. The transmission is produced at the firm ZF in Saarbrücken, and is an automatic five-speed sports transmission with integrated hypoid axle drive with manual and automatic shifting. Repairing Similar to Tiptronic transmission type A50, repair work on transmission type A96 is limited to replacing or repairing: The greater the difference in speed between the impeller and turbine, the greater the torque increase which is at its maximum when the turbine is stationary. The torque increase drops as the turbine speed increases. If the turbine speed reaches approx. 85% of the impeller speed, the torque increase is 1, i.e. the turbine speed is equal to the impeller speed. The stator which is supported by the overrun clutch and the stator shaft to the transmission housing now runs free parallel to the flow and the overrun clutch overruns. From this point onwards, the converter functions as a pure flow clutch. During conversion, the stator is stationary and is supported by the overrun clutch to the housing. Selector lever switch and cable Valve body ATF Filter, pan and gasket Solenoid valves Pressure regulator for modulation pressure Leak repair at the filler and drain plugs Differential ATF lines and cooler on transmission Torque converter Driveshaft flanges and seals Page 6.6 Drivetrain Repair Sports Cars

47 Tiptronic Transmission Regulated Converter Lockup Clutch The converter lockup clutch (CLC) is a device which eliminates slippage of the converter and thus contributes to the optimization of fuel consumption and to a sporty style of driving. In the new 911 Carrera (996), control of the CLC actuation has been replaced by a regulation function. Intervention and opening of the CLC is regulated. During the regulation phase, a differential speed of approx. 50 rpm between pump and turbine is set. This prevents the torsional vibrations from the engine from being transmitted to the transmission which, in turn, optimizes shifting smoothness. Tiptronic Transmission Operation Like the Tiptronic of the 911 Carrera (993), the Tiptronic of the new 911 Carrera (996) has two selector gates. In the right-hand gate and with the selector lever in position D, shifting into higher and lower gears is performed automatically. No gear lock is provided which means that only the selector-lever positions P - R - N - D are available. Pressure regulation at the CLC pistons is determined by an electronic pressure control valve (EPCV 4). When open (conversion range), the oil pressure is adjusted after the CLC pistons as well as in the turbine range. The direction of flow is determined by the turbine shaft through the area behind the pistons to the turbine chamber. To close the CLC, the direction of flow is changed (reversed) by a valve in the hydraulic control unit (EPCV 4). At the same time, the space behind the CLC piston is bled. The oil pressure moves from the turbine chamber to the CLC piston and forces it against the cover (outer shell) of the converter. As a result, the turbine is locked by the lining disk between the piston and cover and allows rigid through-drive to the planetary transmission without slippage or slippage (in the case of regulated operation). Notes: P = Park R = Reverse N = Neutral (idle) D = Drive (automatic shifting 1st - 2nd - 3rd - 4th - 5th gear) Driving In Selector-lever Position D If the selector lever is moved to D, an extremely intelligent driving program is performed. Shift characteristics adaptation is carried out on the basis of the following information: Accelerator pedal position - Throttle potentiometer Vehicle speed - ABS sensors Longitudinal vehicle accel. - ABS sensors Transversal vehicle accel. - ABS sensors Engine speed - Speed sensor/ flywheel Apart from the driving style, when the shift map is selected, the shift program also takes into consideration the road resistance, changes to which are particularly noticeable on upward and downward slopes. Drivetrain Repair Sports Cars Page 6.7

48 Tiptronic Transmission When these changes are detected, the shift map providing the optimum gear is selected according to the slope. This results in a reduction in shifting frequency. Apart from the five shift characteristics ranging from SK 1 = very comfortable and economical to SK 5 = very sporty with high performance The Tiptronic transmission also has the following special functions: Prevention Of Thrust Upshifting e.g. Before Curves If the accelerator pedal is released before a curve, i.e. the throttle is closed quickly, the gear currently being used is retained. If the brake is then actuated, downshifting, appropriate to the current speed, is performed so that the optimum gear is available for the approaching curve. If the throttle is opened again, shifting occurs according to the shift program. Gear Retention In Corners The current lateral acceleration is calculated from the current driving speed as well as the difference in engine speed. In corners, the respective gear is retained depending on the shift characteristics and lateral acceleration. Downshifting When Braking If the throttle is closed, downshifting is triggered when the brake is actuated, depending on the speed and the defined braking deceleration. The gear then activated remains engaged until the driver once again depresses the accelerator pedal. This function allows the engine braking effect to be used when braking in curves or when driving downhill. In addition, the correct gear is then already available before the vehicle enters the curve. next gear occurs with higher engine speeds. The kickdown shift speeds remain active until the accelerator has been returned to 70% of its full-throttle position. Shift-up With Deceleration On Slippery (Icy) Road Surfaces In deceleration conditions, especially in the low gears and on slippery road surfaces, the engine braking effect may cause slippage or locking of the driven wheels. This driving condition is detected by the Tiptronic control unit which continuously compares the speed of the driven rear wheels with the speed of the front wheels. If the speed of the rear wheels is less than that of the front wheels, the Tiptronic system immediately shifts the transmission into a higher gear so that the dangerous driving condition with locking rear wheels cannot occur. Warm-up Map Apart from the 5 shift characteristics, the control unit also has a warm-up map which becomes active at engine temperatures < 90 F. (32 C.). In the warm-up map, the shift-up points are offset to higher engine speeds, the transmission starts in 1st gear, and the convertor lockup clutch is opened. These measures result in both the engine and catalytic convertor rapidly reaching operating temperature. Suppression Of Ignition At Gear Shift When gear shifting is performed, the DME control unit briefly suppresses the ignition in order to reduce the engine torque which, in turn, results in smooth shifting. Notes: Active Gear Shift Skip Into SC 5 Whenever the vehicle is started, the transmission control unit has the shift characteristics SC 1. An active gear shift skip into SC 5 can be achieved irrespective of the shift characteristics by quickly opening the throttle. If the throttle is now closed by more than 25%, the previous shift characteristics are resumed. Kick-down To achieve optimum acceleration, e.g. when overtaking another vehicle the accelerator pedal must be depressed beyond the full-throttle pressure point (kick-down). The transmission may shift back down to the lowest possible gear, depending on the driving speed. Shifting up to the Page 6.8 Drivetrain Repair Sports Cars

49 Tiptronic Transmission Driving In The Manual Program If the selector lever is moved from D and to the left, the currently selected gear remains engaged. By pressing the switches on the steering wheel, it is now possible to quickly execute up-shifts and down-shifts. Manually actuated up-shifts and down-shifts are monitored by the Tiptronic control unit and are not permitted above or below speed limits. M as well as the actual gear are displayed in the instrument cluster. Tow-Starting The vehicle cannot be tow-started and no attempt should be made to do so otherwise considerable damage could be caused to the transmission. With the limited driving program, the transmission functions without electric actuation in direct 4th gear and with no converter lockup. The reverse gear and the parking lock are available. Note: The reverse gear lock is not effective in the limited driving program. Towing Sufficient lubrication of the transmission cannot be ensured if the engine is not running. The following points must therefore be observed: 1 - Select the selector lever position N 2 - Maximum speed: 30 mph (50 km/h) 3 - Maximum towing distance: 30 miles (50 km) 4 - With greater towing distances, the vehicle must be raised at its rear axle or transported on a trailer. Notes: Limited Driving Program If an electric or electronic fault occurs when the Tiptronic drive system is in use, the Tiptronic control unit deactivates automatically and switches to a limited driving program depending on the type of fault. If the limited driving program is activated, the position display and the 4th gear flash alternately (e.g. D and 4 ) in the instrument cluster. The Following Always Applies: It is absolutely safe to continue driving the vehicle for any distance even if the electronic link between the Tiptronic control unit and the transmission is no longer functioning. Drivetrain Repair Sports Cars Page 6.9

50 Tiptronic Transmission How The Tiptronic Control Unit Processes Information The following measured variables are transmitted and processed several times per second: Measured Variable Type of Measurement Position of throttle valve...resistance value, potentiometer Actuation speed of throttle valve...time for resistance change at potentiometer Engine speed...frequency measurement (from DME) Driving speed...number of pulses from ABS Vehicle's lateral acceleration...calculation using driving speed and difference between front wheel speeds Vehicle's acceleration/deceleration...change in pulse time (ABS) within cycle time Change in road resistance...resistance value, potentiometer for frequency measurement (DME) Braking, yes/no...pulse for brake light switch Engine temperature...resistance value, NTC Solenoid Valve Logic (S) = Activated if converter lockup clutch (CLC) is regulated or closed * = Electric pressure control valve ** = Only active with shift-down 5-4 Page 6.10 Drivetrain Repair Sports Cars

51 Tiptronic Transmission Valve Body Solenoid Valves (MV 1, 2, 3) The solenoid valves, each with three connections, are triggered by the electronic transmission control unit and have the switch settings open or closed. They are used to switch slider valves in the slider valve box. ATF Cooling The ATF fluid heats up and must be cooled, this especially applies to operation with open converter lockup clutch. An ATF-to-water heat exchanger (1) attached to the transmission is used for cooling. Electric Pressure Control Valves (EDSV 1, 2, 3, 4) The pressure control valves convert an electric current into a proportional, hydraulic pressure. They are triggered by the electronic transmission control unit and actuate the switching sliding valves belonging to the switching elements. ATF Heat Exchanger Valve Body Depending on the ATF and water temperature, the electric switch-over valve (2) is activated by the Tiptronic control unit (1) and allows a vacuum to enter the shut-off valve (3). The electric switch-over valve is activated at an ATF temperature > 185 F. (85 C.) or water temperature >194 F. (90 C.). The switch-over valve is deactivated again if the ATF temperature falls below 167 F. (75 C.) and the water temperature below 176 F. (80 C.). 1 - Engine speed sensor 2 - EPCV 1 for modulation pressure 3 - SV 1 for gears R/N/1/2/5 4 - EPCV 2 for gears 2/3/5 5 - EPCV 4 for converter lockup clutch 6 - EPCV 3 for gears R/N/1/2 7 - SV 2 for gears N/1/2/3 8 - SV 3 for shift-down 5-4 Notes: ATF Cooling System Schematic 1 - Tiptronic control unit 2 - Electric switch-over valve 3 - Vacuum-controlled shut-off valve 4 - ATF-to-water heat exchanger Drivetrain Repair Sports Cars Page 6.11

52 Tiptronic Transmission Electronic Control Unit Notes: Tiptronic Control Unit Location The 88-pole transmission control unit (2) is installed in the passenger compartment under the storage shelf behind the rear seat backrests (under the DME control unit). Diagnosis can be performed with this control unit using the PIWIS Tester. Multifunction Switch The multifunction switch is attached to the transmission and does not have to be adjusted. 9 of the 10 pins on the switch are assigned. Lines 1-4 are reserved for the information sent to the Tiptronic control unit regarding the position of the selector lever. If the selector lever is at an intermediate position (e.g. Z 1 = R flashes), the indicator flashes. Page 6.12 Drivetrain Repair Sports Cars

53 Tiptronic Transmission Transmission A96.10/35/50, A97.01//31 5-speed The 911 Carrera (997) and 911 Carrera S (997) use the proven 5-speed Tiptronic transmission from the 911 Carrera (996), model year The torque and performance potential of this transmission covers even the higher requirements of the new engines. The shift pressures have been increased to adapt to the transmission of the higher torques, in particular those of the 3.8 liter engine. An improvement in shifting comfort has been achieved through the fine-tuning of oil pressure buildup during the course of shifting. Overview of modifications: Tiptronic Transmission Type A 96.10/A Carrera 2 (996/997) In model year Turbo came equipped with a optional Tiptronic transmission, type A It was a completey new design when compared to the previous 911 Carrera (996) Tiptronic transmission type A96.00/30. In model year 2002 this new transmssion also replaced the previous ZF built transmission type A96.00/30 in the 911 Carrera 2/4 (996). The new type designation became A96.10 and A The basic transmission A96.10/35/50 is manufactured by DaimlerChrysler under the internal type designation W5A 580. W - Hydraulic torque converter 5 - Number of forward gears A - Internal mode code Max. input torque in Nm In order to satisfy handling dynamics requirements, the familiar shift strategies and special functions have also been adopted here. Adaptation of transmission ratio Upshift suppression in manual gate when "PSM OFF" is activated Revving function in overrun state Additional Sport Chrono function resulting in shorter shifting times Modified torque converter characteristic curve Engine can be revved up to rpm limitation in "P" and "N" Modified plates to improve shifting comfort New light-running oil and extended oil-changing interval Modified cruise control function Repairing Similar to previous Tiptronic transmissions, repair work on transmission types A96.10/35/50, A97.01/31 is limited to replacing or repairing: Sealing rings Valve body ATF Filter, pan and gasket Torque Convertor Repair to the automatic section is not permited and requires replacement of complete units. Capacities Fluid capacities and types can be found in each models Owner s Manual, Technical Manual and Technical Information Bulletins. Always refer to these before performing maintenance service. Diagnosis PIWIS Tester is used. Drivetrain Repair Sports Cars Page 6.13

54 Tiptronic Transmission Tiptronic Operation Notes: Like the Tiptronic used in previous models, the Tiptronic has two selector gates. In the right-hand gate and with the selector lever in position "D", shifting into higher and lower gears is performed automatically. If the selector lever is moved into the left-hand gate ("M"), it is possible to shift into higher and lower gears manually. As with previous models, no gear lock is provided which means that the selector lever positions P R N D are available. P = Park R = Reverse N = Neutral D = Drive (automatic shifting 1st 2nd 3rd 4th 5th gear) M = Manual program Page 6.14 Drivetrain Repair Sports Cars

55 How The Tiptronic Control Unit Processes Information, A96.10/35/ Carrera (996) Tiptronic Transmission Driving In Selector Lever Position "D" If the selector lever is moved to "D", an extremely intelligent driving program is performed. Virtually stepless adaptation to the driving style and road conditions is carried out on the basis of the fol-lowing information. Variable Accelerator pedal position Type of measurement resistance value and change in resistance at potentiometer of accelerator pedal sensor over a certain period, by DME control unit via CAN* Vehicle speed by PSM control unit via CAN Longitudinal vehicle acceleration by PSM control unit via CAN Lateral vehicle acceleration signal from lateral acceleration sensor of PSM Engine speed by DME control unit via CAN Road resistance (incline) calculated value for vehicle speed and accelerator pedal position from DME control unit Altitude Pressure sensor in DME control unit * CAN = Controller Area Network Notes: Drivetrain Repair Sports Cars Page 6.15

56 Tiptronic Transmission Gearshift Strategies A96.10/35/ Carrera (996) The Tiptronic control unit determines the driver s current requirements on the basis of the incoming information and then changes to an appropriate map. In contrast to previous transmissions, the new Tiptronic control unit has 250 different shift maps instead of just five. The maps permit virtually step-less adaptation. While selecting this adaption, along with the driving style, the shift program also takes into consideration the driving resistance, which is particularly noticeable on uphill and downhill stretches. Furthermore, the Tiptronic control unit also calculates an altitude correction factor, i.e. since the volumetric efficiency of the engine decreases with increasing altitude, the driver automatically accelerates more and the transmission would change over to a map with more frequent gear shifting. However, this situation is detected by the altitude sensor and the map most suitable for the driver continues to be provided. Apart from the stepless adaptation to the driver s requirements ranging from very smooth and economical to very sporty and power-oriented, the Porsche Tiptronic also has the following special functions: Prevention Of Thrust Upshifting, E.G. Before Curves If the accelerator pedal is released before a curve, i.e. the throttle is closed quickly, the gear currently being used is retained. If the brake is then also actuated, downshifting appropriate to the current vehicle speed is performed so that the engine braking torque is provided before the curve and the optimum gear is selected for acceleration out of the curve. If the accelerator pedal is depressed again (the throttle is opened), shifting is again performed according to the driver s requirements. Gear Retention When Cornering The lateral acceleration sensor (integrated in the same component as the rotary speed sensor), which is located on the center console and pro-vides the PSM system with information, detects the lateral acceleration and retains the respective gear depending on the map and lateral acceleration. Active Gear Skip Into Most Sporty Shift Map Whenever the vehicle is started, the transmission control unit is set to the smoothest and most economical shift map. In order to achieve the best possible acceleration (e.g. for an overtaking maneuver), the associated fast movement of the accelerator pedal is detected by the potentiometer and the transmission changes over to the more sporty and power oriented shift map. If the accelerator pedal is now released by more than 25%, the previous shift characteristics are resumed. Kick-down If the accelerator pedal is depressed beyond the full-throttle pressure point (kick-down), e.g. when passing, the transmission shifts down to the lowest possible gear and most sporty shift map for the current vehicle speed. This map is retained until the accelerator is released by more than 70%, and then the previous shift characteristics are resumed. Shift-up With Overrun On Slippery (Icy) Road Surfaces In overrun conditions, especially in the low gears and on slippery road surfaces, the engine braking effect may cause slippage or locking of the rear wheels. This driving condition is detected by the Tiptronic control unit which continuously compares the speed of the rear wheels with the speed of the front wheels. If the speed of the rear wheels is less than that of the front wheels, the transmission immediately shifts into a higher gear so that the speed of the rear wheels matches the speed of the front wheels and the hazardous driving situation with locking rear wheels cannot occur. If the "PSM off" button is pressed, the function described above is also deactivated and can only be reactivated by pressing the button again or by switching the ignition off and then on again. On vehicles without PSM, switching off of this function is not possible. Downshifting When Braking If the accelerator pedal is released quickly, e.g. in a hazardous situation or when approaching curves (sporty driving style), and the brake is also actuated, the transmission shifts down to the lowest possible gear for the vehicle speed. The gear which is then activated remains engaged until the driver once again depresses the accelerator pedal. This function allows the engine braking effect to be used. This also applies to downhill driving. Page 6.16 Drivetrain Repair Sports Cars

57 Tiptronic Transmission Warm-up Map A warm-up map which is activated at engine temperatures < 90 F. (32 C.) is integrated in the stepless shift map adaptation. In the warmup map, the shift-up points are offset to higher engine speeds, the transmission starts in 1st gear and the torque converter lockup clutch is opened. If the reverse gear is engaged during the warm-up phase, the vehicle starts in a short reverse gear. These measures result in both the engine and catalytic converter rapidly reaching their operating temperatures. Driving In Manual Program If the gear selector lever is moved from "D" and to the left, the currently selected gear remains engaged. By pressing the switches on the steering wheel, it is now possible to quickly execute upshifts and downshifts. Manually actuated upshifts and downshifts are monitored by the Tiptronic control unit and are not permitted above or below defined limit speeds. The transmission shifts automatically up or down at certain limit speeds. Unlike previous transmissions, the new Tiptronic transmission shifts back into the first gear if the vehicle is started in first gear and then stopped again. In addition, if the selector lever passes through "N" as it is moved to a different position, the first gear is always engaged for approx. one second, irrespective of temperature. If the vehicle is driven off during this time, the transmission shifts into the first gear. Road Resistance The road resistance can be derived from the position of the accelerator pedal, the engine speed and vehicle speed, and the transmission can then be changed to a shift map which provides the best gear. This, in turn, reduces shift frequency. Reduction In Engine Torque When gear shifting is performed, the DME control unit briefly suppresses ignition in order to reduce engine torque which, in turn, ensures smooth shifting. Manual Intervention In Selector Position "D" To permit manual downshifting in the automatic gate, e.g. "M" As Well As The Actual Gear Are Displayed In The Instrument Cluster. Notes: before curves when entering built-up areas when driving downhill when selecting first gear before moving off It is also possible to actuate the upshift and downshift buttons in the automatic gate, i.e. the Tiptronic enters the manual program when the upshift or downshift button is pressed. "M" appears in the instrument cluster and the required shift operation is performed. At the same time, an 8-second timer is started in the control unit. If the upshift or downshift button is pressed again within the 8 seconds, the timer is restarted. The Tiptronic automatically returns to automatic mode ("D" appears in the instrument cluster) if: the timer has expired, the vehicle is not cornering and is not decelerating. the driver has activated the kick-down function. Drivetrain Repair Sports Cars Page 6.17

58 Tiptronic Transmission How The Tiptronic Control Unit Processes Information, A97.01/ Carrera (997) The established gearshift strategies of Tiptronic S have been largely retained for the new 911 Carrera/4 (997) and 911 Carrera S/4S (997). These are complemented by the new special function Sport Chrono as well as modified shifting functions for when the PSM function is OFF. Gearshift Strategies A97.01/ Carrera (997) Similarly to the 911 Carrera (996), model year 2004, the automatic program is also influenced by the following functions: Suppression of upshifts during rapid throttle lift, for example before a corner. Earlier downshifts when braking depending on the driving speed and deceleration. Adjustment of the shift points due to incline detection. Here gradients or ascents are identified by comparing the actual and desired acceleration. Adjustment of the shift points as a function of the geographic elevation. Suppression of upshift in corners depending on the driving speed and lateral acceleration. The selected gear is maintained for at least 8 seconds. The holding time is extended depending on the driving conditions (deceleration and lateral acceleration). The system then automatically switches back to automatic mode. Kickdown results in an immediate return to the automatic program. The selector lever must be moved to position M if the driver wishes to shift the gears. The gears are then changed manually using the one-touch switches on the steering wheel. In this case the permissible shifting speeds are monitored and the gearshift only executed if the engine rpm limits are adhered to. Despite all of the functions listed, there will be driving situations in which it makes sense to be able to manually override the automatic program via the one-touch switches on the steering wheel. This function is also integrated, i.e. pressing one of the switches on the steering wheel will execute the corresponding function even if the selector lever is in position "P". Page 6.18 Drivetrain Repair Sports Cars

59 Tiptronic Transmission Upshift Suppression With "PSM OFF" The 911 Carrera/4 (997) and 911 Carrera S/4S (997) are equipped with an upshift suppresser which takes effect when the "PSM OFF" switch is active and the manual setting is selected on the gear shift lever, in order to enhance the sporty character of Tiptronic S. Upshifts are prevented when the engine speed limit is reached in the "M" position, allowing the engine to run in the range of the speed limiter. The same also applies in position "D", in one-touch mode for temporary override. When kickdown is activated, however, upshift will be effected when the engine speed limit is reached. Revving Function During Deceleration State Examples of downshifts in deceleration state include automatic downshifts when braking or downshifts activated via the one-touch switches on the steering wheel. This function initiates revving for downshifts in deceleration state to reduce shifting times, to improve shifting comfort and to actively prevent the rear wheels locking. The EDTC function (engine drag torque control) also stops the rear wheels locking as part of PSM, however it does so in response to detection of impermissibly high rear-wheel slip. In contrast, the revving function via Tiptronic S prevents active locking of the rear wheels in overrun state. Shift Gate "M" When the Sport Chrono switch is pressed with the gear shift lever in shift gate "M", no automatic upshift will be effected when the engine speed limit is reached. This function allows the driver to operate the engine in the range of the engine speed limiter for the first time, even on vehicles with Tiptronic. This reinforces the sporty character of the Sport Chrono function. Upshift suppression is only active in the manual shift gate; it is not active in the "D" shift gate or in one-touch mode for temporary override in shift gate "D". Upshift when the engine speed limit is reached can be overridden via the kickdown function. When the engine speed limit is reached in M gate during an passing manoeuvre, for example, upshift can be executed even without pressing the switches on the steering wheel, by means of a kickdown. This measure boosts the acceleration potential and speeds up the passing process in this situation. This is the only function whereby a kickdown results in an upshift rather than a downshift. Notes: Sport Chrono Function The Sport Chrono package is offered as an option on the new 911 Carrera and 911 Carrera S. This option provides for an even more sporty driving experience, particularly when using vehicle on race circuits. Shift Gate "D" Pressing the Sport Chrono switch when the gear shift lever is in shift gate "D" boosts the basic gear-changing map. This raises the engine speeds for gear-changing and renders gear-changing sportier by shortening the shifting times. The reduction in shifting times results from faster filling of the clutches with oil (response time) and a higher oil pressure level when performing the shift operation. These measures lend the shift operations a more dynamic and noticeably sportier character. The shift points are then adjusted between this boosted basic gear-changing map and the sport gear-changing map according to the present driving style. System downshifts are initiated at lower acceleration and higher speeds (in comparison with when the Sport Chrono switch is off) to increase agility. Drivetrain Repair Sports Cars Page 6.19

60 Tiptronic Transmission Torque Converter A96.10/35/ Carrera (996) Functional description of torque converter The torque converter consists of the impeller, turbine, stator and the oil required for torque transmission. The impeller driven by the engine causes the oil in the torque converter to be pumped in a circular flow. This oil flow reaches the turbine and its flow direction is changed. The oil leaves the turbine at the hub and flows to the stator where its direction is once again changed. The oil is thus supplied to the impeller in the appropriate flow direction. Regulated Torque Converter Lockup Clutch The torque converter lockup clutch (CLC) is a device which eliminates slippage of the torque converter and thus contributes to the optimization of fuel consumption and to a sporty style of driving. The change in direction creates a moment at the stator. The reaction moment of this moment increases the turbine moment. The ratio of turbine moment to pump moment is known as the moment increase. The greater the difference in speed between the pump and turbine is, the greater the moment increase (which is at its maximum when the turbine is stationary) will be. The moment increase drops as the turbine speed increases. If the turbine speed reaches approx. 85% of the pump speed, the moment increase is 1, i.e. the turbine moment is equal to the pump moment. The stator which is held off the transmission case by the overrunning clutch and the stator shaft now runs freely parallel to the flow and the overrunning clutch overruns. From this point onwards, the torque converter functions purely as a hydraulic clutch. During conversion, the stator is stationary and is held off the case by the overrunning clutch. Torque Converter A97.01/ Carrera (997) Starting performance has been improved by altering the characteristic of the torque converter. To further improve acceleration when the accelerator pedal is pressed quickly followed by a downshift into 1st gear, the converter's bridging coupling is now closed in this situation, thereby reducing slip. A further improvement in acceleration when shifting from first to second gear has been produced by increasing the rpm of the shift point (from approx rpm to 6300 rpm), thereby realizing a higher shifting speed (7200 rpm instead of 6900 rpm) and a shorter shifting time. In order to further enhance the sporty character of Tiptronic S, in the 911 Carrera and the 911 Carrera S the engine can also be revved up to the engine speed limit when the vehicle is stationary, when the selector lever is set to "P" and "N". Important: If the engine is revved to over 2500 rpm when the selector lever is set to "P" or "N" and a gear is then engaged, the injection signal will be blocked until the engine speed drops to a level which cannot cause any damage to the transmission. Torque Converter Construction 1 - Impeller 2 - Turbine 3 - Stator 4 - Stator shaft 5 - Outer disc carrier 6 - Inner disc carrier 7 - Case shell 8 - Overrunning clutch 9 - Input shaft 10 - Disc pack 11 - Piston The CLC is controlled by a pulse-widthmodulated solenoid valve which converts the pulse-width-modulated input current into an appropriate pressure. This pressure activates a CLC control valve. Depending on the pressure level, the torque converter clutch is either: activated deactivated or in regulated operating mode In the regulated phase, a speed differential between the impeller and turbine of ca. 50 rpm is set. As a result, the torsional vibrations of the engine are not transferred to the transmission. This procedure optimizes shift quality and reduces noise. Page 6.20 Drivetrain Repair Sports Cars

61 Tiptronic Transmission Design The outer disc carrier (5) is connected to the impeller (1) via the case shell (7). The inner disc carrier (6) is connected to the turbine (2). Function: When triggered by the ETC control unit, oil pressure produced by the PWM solenoid valve is fed through the input shaft (9) to the pressure chamber behind the piston (11). The piston pushes the disc pack (10) together and thus permits direct torque transmission between the impeller and turbine. Converter clutch activation depends on the engine speed and engine load and is only possible in 2nd gear or higher. Note: To protect the converter, the engine speed is restricted to rpm if no driving speed signal is present. Towing Sufficient lubrication of the transmission cannot be ensured if the engine is not running.therefore, the following conditions must be observed when towing the vehicle: 1. Move selector lever to N. 2. Maximum speed: 50 km/h (30 mph). 3. Maximum towing distance: 50 km (30 miles). 4. With greater towing distances, the vehicle must be transported on a trailer. Due to the four-wheel drive, the vehicle must not be raised at its rear axle. Selector Lever Lock At speeds over 10 km/h (6 mph), a R/P lock is activated. This prevents the selector lever from being moved in to R or P inadvertently while the vehicle is being driven. Functional Description Limited Driving Program If a Tiptronic electric or electronic fault occurs when the system is in use, the Tiptronic control module deactivates automatically and switches to a limited driving program depending on the type of fault. Effect: The gear last selected remains engaged (initial intervention) The modulating pressure and shifting pressure increase to the maximum value. The torque converter lockup clutch is deactivated. If the selector lever is moved to P, the engine is switched off and on again (after approx. 10 seconds) and the selector lever moved to D, the transmission is shifted to 2nd gear. Reverse gear is also available. When in the limited driving program, the selector lever position and 4th gear are displayed alternately (e.g. D and 4 ) in the instrument cluster. It is safe to continue driving the vehicle in the limited driving program even if the electronic link between the Tiptronic control module and the transmission is no longer functioning. Selector Lever Reverse/park Lockout Mechanism. 1 - Selector shaft 2 - Lever 3 - Cam 4 - Supporting lever 5 - Operating solenoid The operating solenoid (5) is actuated by the Tiptronic control module and moves the lever (2) towards the cam (3) to lock the selector shaft (1). When the solenoid is de-energized, the supporting lever (4) holds the lever (2) in position so that it does not engage in the case of severe vibrations. Tow-starting The vehicle cannot be tow-started and no attempt should be made to do so, otherwise considerable damage could be caused to the transmission. Drivetrain Repair Sports Cars Page 6.21

62 Tiptronic Transmission Valve Body 1 - Valve body 2 - Selector valve 3 - Plastic base 4 - Pressure control valve, modulating pressure 5 - Pressure control valve, shifting pressure 6 - Solenoid valve, 1-2 and 4-5 shifting 7 - Solenoid valve, 3-4 shifting 8 - Solenoid valve, 2-3 shifting 9 - Solenoid valve, Converter Lockup Clutch 10 - Speed sensor 11 - Speed sensor 12 - Starter interlock contact 13 - Temperature sensor Valve Body These electrical components are mounted to a plastic base (3). The components are electrically linked to the 13-pin plug connector via conductors in the base. All electrical components, with the exception of the valves, are connected to the conductors. A cable gland forms the connection to the vehicle wiring harness and the Tiptronic control module. The valve body is aligned to the mounting plate by two centering pins. The valve body is a two-piece component. The two sections are joined with three bolts. This bolted connection also serves to preload the flat springs for the solenoid and pressure control valves. The valve body (1) containing the solenoid valves and pressure control valves converts the electrical signals from the Tiptronic control module into hydraulic functions. The sensors in the valve body supply the Tiptronic control module with electrical input signals. The valve body consists of four solenoid valves (6, 7, 8, 9) and two pressure control valves (4,5), the starter interlock contact (12), two speed sensors (10, 11), a temperature sensor (13), and a 13-pin harness connector. Page 6.22 Drivetrain Repair Sports Cars

63 Tiptronic Transmission Solenoid Valves The solenoid valves are 3/2-way valves and are actuated by the Tiptronic control unit to initiate upshifts and downshifts. If a solenoid valve is actuated, it opens and directs control pressure to the assigned command slide valve. The solenoid valve remains actuated and therefore open until the shifting operation has been completed. If the solenoid valve is de-energized, the pressure along the control line to the command slide valve is reduced to zero. Pressure Control Valves The pressure control valves convert an electrical current into a proportional, hydraulic pressure and control the modulating and shifting pressure according to various variable operating conditions. The pressure control valves have a locating seat. A slit seal (arrow) forms the seal between the pressure control valve and valve body. PWM Solenoid Valve, CLC Two O-rings (1 and 2) form the seal between the solenoid valves and the control plate. The valves are pressed against the control plate (4) by flat springs (3). The contact springs (5) on the solenoid valve engage in a slot in the conductors (6). The spring force ensures reliable contacting. The PWM solenoid valve, actuated by a pulsewidth-modulated input current, supplies appropriate pressure for the torque converter lockup clutch. It is sealed with an O-ring and a slit seal (arrow). Drivetrain Repair Sports Cars Page 6.23

64 Tiptronic Transmission Speed Sensor The speed sensors are used to determine the transmission input and output speeds and also pass these signals on to the Tiptronic control unit for further processing. Starter Interlock Contact The starter interlock contact is used to detect when the selector lever is at "P" and "N". This information is passed on to the Tiptronic control unit Speed sensor 11 - Speed sensor 14 - Pulse rings 15 - Flat spring The speed sensors (10 and 11) are fixed to the base via contact studs. The speed sensors are pressed against the transmission case by the flat spring (15) which is supported by the valve body. This arrangement ensures a defined gap between the speed sensors and pulse rings (14). ATF Temperature Sensor The ATF temperature has a major effect on the shifting time and, therefore, on shifting quality. By establishing the temperature of the ATF, it is possible to optimize shifting in all temperature ranges. The temperature switch is connected to the starter interlock switch in series, i.e. the temperature signal only reaches the Tiptronic control unit if the reed contact is closed. 1 - Plunger 2 - Permanent magnet 3 - Reed contact Functional Description When the selector lever is at "P" and "N", the permanent magnet (2) is moved away from the reed contact (3) and thus opened. The Tiptronic control unit uses this electrical signal to determine the position of the selector lever. This information is passed on to the DME control unit which then issues the start release. New Light-running Oil/Modified Plates A97.01/ Carrera (997) As a model improvement, all Tiptronic transmissions in the 911 (997) series for model year 2005 use a new ATF light-running oil as well as modified plates. The modified plates improve shifting comfort and the light-running oil reduces friction losses in the gearbox. The new lightrunning oil also enables the ATF change intervals to be extended from 90,000 miles to 120,000 miles. Cruise Control Function A97.01/ Carrera (997) An additional new function of Tiptronic S for the 911 (997) series is active downshifting when travelling downhill with the cruise control function selected. Previously, acceleration of the vehicle to a speed beyond the selected setting could occur in high gears when travelling downhill (without active downshifting by the driver) despite a cruise control function being selected. The new function for downshifting in cruise control mode ensures a constant speed, even when travelling downhill. Page 6.24 Drivetrain Repair Sports Cars

65 Tiptronic Transmission ATF Cooling Multifunction Switch The multifunction switch (MFS) is attached directly to the selector lever bracket and cannot be replaced separately. An additional 2-pin plug for the reverse lamp is attached to the MFS. PIN 1 connects earth to the reverse lamp. PIN 2 connects terminal 15 to the reverse lamp. ATF Heat Exchanger Location The ATF fluid heats up and must be cooled; this especially applies to operation with open torque converter lockup clutch. An ATF-to-water heat exchanger attached to the transmission is used for cooling. Depending on the ATF and water temperature, the electric switch-over valve is actuated by the DME control unit and allows a vacuum to enter the shut-off valve. Malfunction Switch The MFS supplies information regarding the position of the selector lever to the instrument cluster and Tiptronic control unit. Notes: Cooling on Coolant temp. > 212 F. (100 C.) ATF temperature > 194 F. (90 C.) Cooling off Coolant temp. < 194 F. (90 C.) ATF temperature < 181 F. (83 C.) The DME control unit reduces power output when the ATF temperature exceeds 290 F. (143 C.). Tiptronic Control Unit Location, Boxster The 32-pole transmission control unit is manufactured by Siemens and is installed on the right-hand side of the passenger compartment at the bottom of the B-post in front of the rear-seat well. Location of Control Unit Drivetrain Repair Sports Cars Page 6.25

66 Tiptronic Transmission Coding and Adaption Of Tiptronic Control Unit Important: Notes: The adaption value must be reset using the PIWIS Tester when the transmission is renewed/replaced. If a new control unit is installed, the control unit must adapt first. Poor shifting quality can be expected while in the adaption phase. After a test drive, let the engine run for 10 minutes at idle speed. This ensures that all the adaption values are stored in the control unit. The instructions of the PIWIS Tester have highest priority. The following procedure has been structured generally, changes or additions can be made. This procedure was based on PST2 Software update Procedure 1. Connect the PIWIS Tester to the vehicle and start the PI- WIS Tester. Switch ignition on. 2. Select vehicle type using the cursor keys. 3. Using the >> key, move from the vehicle type to the list of control modules. 4. Select Tiptronic with the cursor keys and press the >> key. 5. Select Coding with the cursor keys and press the >> key. 6. Select vehicle version and code with the F8 key. 7. Tester confirmed: Coding has been modified. 8. Perform test drive and check fault memory with the System Tester. Resetting Adaption Values - Proceed as described under steps Select menu item Reset adaption values proceed with >>. 9. Confirm with F7 for yes, F8 for no and proceed with >>. 10. Follow the instructions of the tester. Page 6.26 Drivetrain Repair Sports Cars

67 Tiptronic Transmission Transmission A86.00/05/20, A87.01/02/20/21 5-speed Diagnosis PIWIS Tester is used. ATF Cooling During operation with open converter lockup clutch, the ATF fluid heats up and must be cooled. An ATF-to-water heat exchanger is attached to the transmission. Tiptronic Transmission Type A86.00 Boxster The Boxster/S & Cayman/S Tiptronic transmissions are similar in design and concept to that of the 911 Carrera (996) Tiptronic transmision type A The transmission is produced at the firm ZF in Saarbrücken, and is an automatic five-speed sports transmission with integrated hypoid axle drive with manual and automatic shifting. Repairing Similar to Tiptronic transmission type A50, major repair work on transmission type A96 is limited to replacing or repairing: Selector lever switch Selector lever cable Valve body ATF Filter, pan and gasket Solenoid valves Pressure regulator for modulation pressure Leak repair at the filler and drain plugs Differential ATF lines ATF cooler on transmission Torque converter Driveshaft flanges and seals Location of Boxster ATF Heat Exchanger Tiptronic Control Unit Location, Boxster An 88 pin control unit is installed at the rear of the luggage compartment by the engine partition panel, next to the DME control unit. Repair to the automatic section is not permited and requires replacement of complete units. Capacities Fluid capacities and types can be found in each models Owner s Manual, Technical Manual and Technical Information Bulletins. Always refer to these before performing maintenance service. Boxster Control Unit Location Drivetrain Repair Sports Cars Page 6.27

68 Tiptronic Transmission Tiptronic S, Type A 87.01/02 Boxster/Cayman (987) General The Boxster/Cayman (987) employ the established and proven 5-gear Tiptronic S transmission used on the previous M.Y Boxster (986) model. The torque and performance potential of this transmission also covers the higher requirements of the new engine. The shift pressures have been increased to adapt to the transmission of the higher torque. Tiptronic S, Type A87.20 Boxster S (987) General The Boxster S (987) employ the established and proven 5- gear Tiptronic S transmission used on the previous M.Y Boxster S (986) model. The torque and performance potential of this transmission also covers the higher requirements of the new engine. The shift pressures have been increased to adapt to the transmission of the higher torques, in particular those of the 3.2 liter engine. Gearshift Strategies The Boxster/S (987) and Cayman (987) feature the established Tiptronic S gearshift strategies. The tuning has been further improved with regard to upgrade and downgrade detection (longest possible use of low gears during uphill or downhill driving) and the height function. Adaptation of the shifting characteristic has been tuned for considerably sportier performance. Tiptronic S, A87.21 Cayman S (987) General The familiar and proven 5-speed Tiptronic S transmission from the Boxster model range is available for the new Cayman S as an option and the range of functions has been increased. The hydraulic and electronic control systems have also been fully revised. The torque and performance potential of this gearbox also covers the higher requirements of the Cayman S engine. Changes in comparison to the Boxster models: Transmission Ratio In order to attain attractive performance and high driving dynamics, the ratio spread (spur gearing and final drive) has been adapted to the Cayman S. The ratio spread (spur gearing x final drive) stands at Gearshift Strategies Variable gearshift programs have been created for the Cayman S, as opposed to fixed shifting characteristics. Additionally, the gearshift strategies for the Cayman S are complimented by the new special function Sport Chrono (optional equipment) as well as modified shifting functions for when the PSM function is OFF. See the A97.01/ Carrera (997) section for information. New Light-running Oil In order to make gear changing as comfortable as possible and to keep the ATF change interval at 120,000 miles (180,000 km), a light-running oil is used. Cruise Control Function Another Tiptronic S function on the Cayman S is active downshifting when travelling downhill with the cruise control function selected. This ensures that the selected speed is maintained when travelling downhill, too. Tiptronic Control Unit Location, Cayman/S The Tiptronic control unit is mounted in the rear luggage compartment, under the right-hand side-panel lining. Page 6.28 Drivetrain Repair Sports Cars

69 PDK Transmission Subject Page General Information Oil Types and Capacities Operation Gearshift Strategy Transmission Gear Layout Synchonization Shifting Power Flow Doppelkuppung Hydraulics Sensors PDK Shift Lever Drivetrain Repair Sports Cars Page 7.1

70 PDK Transmission Porsche Doppelkupplung (PDK) This technical description covers the design and operating principle of the 7-speed dual-clutch transmission, called PDK (Porsche Doppel Kupplung) at Porsche. Since this transmission is used in several different Porsche models, only the basic functions will be described here. Boxster/Cayman (987) Introduction Porsche has worked with Doppelkupplung transmissions since the '70s. The first racing car with PDK was used in 1984 in the Porsche 956 at Nürburgring, while Porsche had its first big win with a PDK transmission in 1986 with the enhanced 962 in Monza. The main advantage over rival vehicles was that gearshifts could be accomplished without interrupting tractive power. This allowed shorter shifting times with significantly improved acceleration for the racing car. This type of transmission proved successful during the highly challenging long-distance World Championships, although two dry clutches were used. The high level of lining wear associated with this type of clutch was not an issue since the clutch plates would be replaced immediately after each race. Standard development was not followed up at that time as control electronics systems and computer capacities in the '80s were not yet sophisticated enough to perform the complex control functions that were essential to meet the comfort requirements for road vehicles. Also, the mechanical control elements for precise hydraulic valve control were not yet fully developed or financially viable at that time. General Information 911 Carrera (997) The Porsche Doppelkupplung transmission (PDK) is both a manual and automatic transmission. The special feature of PDK is that two gears can always be engaged one gear is engaged while driving and the next potential gear is already pre-selected. When shifting, the clutch on the active gear opens while the other clutch engages the pre-selected gear at the same time. This happens under load and so quickly that the power flow is permanently available. Due to its fast gear changes without any significant power flow interruption, the 7-speed Doppelkupplung transmission offers much better driving dynamics than a conventional manual transmission, with the convenience of an automatic transmission. The superbly sporty driving dynamics are complemented by a high level of efficiency, which results in reduced fuel consumption compared with a conventional manual transmission in certain driving situations. PDK transmission is available for the MY 2009 Boxster/Cayman (987) and for both the rear-wheel-drive and all-wheel-drive 911 Carrera models. Page 7.2 Drivetrain Repair Sports Cars

71 PDK Transmission Oil Types/Oil Capacity/Oil Change Intervals Due to high shearing strains that occur in the differential, two different oil chambers are used in the Porsche Doppelkupplung transmission. The oil chamber for hydraulic oil is shown in red, while the oil chamber for gear wheel oil is shown in blue in the illustration above liters of Mobilube PTX Formula A (SAE 75W-90) GL4.5 are used in the transmission for lubricating the gear wheel set. 5.2 liters of Pentosin Gear Oil FFL3 are used as hydraulic oil. Oil Filling The correct hydraulic oil level is important for operating the transmission without running into problems. The following preconditions must be met in order to check or correct the oil level: Engine must be idling Vehicle must be horizontal in both longitudinal and transverse axis Hydraulic oil temperature between 86 F. and 104 F. (30 C and 40 C) Selector-lever position P Clutch cooling volume flow must be switched off (using PIWIS Tester in Oil fill mode) Retain the described states for approx. 1 minute to allow the oil to settle Open screw plug on oil overflow bore and collect emerging oil until only drops of oil are emerging Once there is no more oil emerging, top up the clutch fluid until oil emerges at the oil overflow bore To avoid damaging the clutches, the procedure must be completed within 5 minutes (PIWIS Tester exits Oil fill mode automatically after 5 minutes) The change interval is 56,000 miles (90,000 km) for hydraulic oil and 112,000 miles (180,000 km) for gear wheel oil. The correct oil level is also important to avoid damaging the gear wheels in the transmission. There is also an overflow bore (1) for this, which is located on the opposite side. The oil level can be checked in the usual way here. Notes: Drivetrain Repair Sports Cars Page 7.3

72 PDK Transmission Transmission Concept In principle, a Doppelkupplung (double clutch) transmission can be understood as a parallel-switched transmission made up of two fully synchronized shift-sleeve transmissions (transmission 1 and transmission 2). Each transmission has its own clutch: Transmission 1, clutch K1 (outer clutch) Transmission 2, clutch K2 (inner clutch) Transmission 1 switches the odd-numbered gears 1, 3, 5, 7 and reverse gear. Transmission 2 switches the evennumbered gears 2, 4 and 6. Basically, only one transmission is ever engaged via the relevant clutch when the vehicle is driving. Operation Like the Porsche Tiptronic transmission used in the previous models, PDK has two selector gates. Upshifts and downshifts are performed automatically in the righthand gate and in selector-lever position D. If the selector lever is moved into the left-hand gate ( M ), upshifts and downshifts can be performed manually. Gears can be changed both on the steering wheel and using the selector lever. There is no gear lock on vehicles with PDK, which means that selector-lever pos itions P - R - N - D are available. mode automatically after 5 minutes) 1 Multiple-disc clutch 1 2 Multiple-disc clutch 2 3 Transmission 1 4 Transmission 2 A Force input B Force output P = Park R = Reverse N = Neutral D = Drive (automatic shifting: 1st 2nd 3rd 4th 5th 6th 7th gear) Page 7.4 Drivetrain Repair Sports Cars

73 PDK Transmission 3-Spoke Sports Steering Wheel for PDK Other displays in the instrument cluster: A flashing selector-lever position in the instrument cluster means that the selector lever is between two positions. Transmission temperature too high prompts the driver to change his driving style. Warning jerks can be felt when driving off and the engine power may be restricted. Do not hold the vehicle on a hill, for example, using the accelerator use the brake pedal instead. Reduce engine load. Stop the vehicle in a suitable place if necessary, and allow the engine to run in selectorlever position N or P until the warning disappears. Transmission emergency run in white letters means that the vehicle can still be driven, but contact a authorized Porsche dealer. Transmission emergency run in red letters means that the vehicle can be driven to a stop, but cannot be driven further. A new 3-spoke sports steering wheel for PDK is used in conjunction with the Doppel kupplung transmission on the new 9x7 models. This completely redesigned steering wheel has two sliding switches, which are incorporated neatly and conveniently into the steering-wheel spokes. Pressing these switches forward changes up a gear, and pulling them or pressing them towards the driver from the back of the steering wheel changes down a gear. It makes no difference whether the left or right sliding switch is used for changing gears. The switches can also be used to activate the One-touch Hold function (see Special functions). Boxster/Cayman (987) Display in Instrument Cluster for PDK Gearshifts for the new Doppelkupplung transmission are displayed in the instrument cluster. The shift indicator is based on an enhanced Tiptronic S concept. In addition to the usual selector-lever position display (Drive mode) via red LEDs, the new instrument cluster also has a numeric gear display. 911 Carrera (997) Drivetrain Repair Sports Cars Page 7.5

74 PDK Transmission Gearshift Strategy The center console includes a Sport and Sport Plus button. The basic gearshift characteristics change, depending on which button is pressed. Driving in selector-lever position M, Sport and Sport Plus button not active Upshifts and downshifts can be performed both on the steering wheel and using the selector lever. Gearshift comfort is therefore adaptive over the entire operating range and adapts to suit the driver's individual driving style. For improved gearshift comfort, the engine torque is reduced while changing gears. Downshifts in deceleration state are accomplished with very little intermediate throttle application and are therefore hardly audible. To avoid under-revving and the associated loss of driving comfort, the current gear is switched down to the next lower gear at engine speeds of less than approx. 1,200 rpm. An upshift at the engine speed limit is only accomplished if there is a kickdown in the speed limiting range (panic shifting). The vehicle always moves off in 1st gear. The Launch Control function (racing start) is not available. Driving in selector-lever position M, Sport button active Upshifts and downshifts can be performed both on the steering wheel and using the selector lever. Gearshift comfort is thus adaptive over the entire operating range and adapts to suit the driver's individual driving style, but basic sportiness is increased. The engine torque is reduced only slightly while changing gears. Downshifts in deceleration state are accomplished with intermediate throttle application. To avoid under-revving and the associated loss of driving comfort, the current gear is switched down to the next lower gear at an engine speed of less than approx. 1,200 rpm. An upshift at the engine speed limit is only accomplished if there is a kickdown in the speed limiting range (panic shifting). The vehicle always moves off in 1st gear. The Launch Control function (racing start) is not available. Driving in selector-lever position M, Sport Plus button active Upshifts and downshifts can be performed both on the steering wheel and using the selector lever. Gearshifts are not adaptive and are purely performance-oriented with a loss of comfort. In addition, the engine torque is not reduced while changing gears. Downshifts in deceleration state involve quick and audible intermediate throttle application with a sporty sound. To avoid under-revving and the associated loss of driving comfort, the current gear is switched down to the next lower gear at an engine speed of less than approx. 1,200 rpm. An upshift at the engine speed limit is only accomplished if there is a kickdown in the engine speed limit range (panic shifting). The vehicle always moves off in 1st gear. 7th gear is not used in this program. The Launch Control function (racing start) is available. Driving in selector-lever position D, Sport and Sport Plus button not active When the selector lever is moved to position D, an extremely intelligent driving program is activated. Shifting adapts continuously and almost seamlessly to the driving style and route profile over the entire operating range. Gearshifts and gearchanging speeds here are changed from economic/ comfortable to sporty. Gearshifts are essentially performed with more emphasis on comfort. Also for improved comfort, the engine torque is reduced during upshifts and downshifts. Downshifts in deceleration state and deceleration downshifts are accomplished with very little intermediate throttle application and are therefore hardly audible. The vehicle moves off in 1st gear. Driving in selector-lever position D, Sport active An extremely intelligent driving program is also activated in this position and shifting adapts continuously and almost seamlessly to the driving style and route profile over the entire operating range. Basic sportiness is increased with faster pick-up and slower deceleration. Gearshifts are more performance-oriented and the engine torque is only reduced slightly during upshifts and downshifts. Downshifts in deceleration state and deceleration downshifts are accomplished with intermediate throttle application and are therefore audible. The vehicle moves off in 1st gear. 7th gear is avoided for the most part and is engaged only at higher speeds. Page 7.6 Drivetrain Repair Sports Cars

75 PDK Transmission Driving in selector-lever position D, Sport Plus active Shift map adaptations are not active in this program. The most sporty map is activated permanently. Gearshifts are performance-oriented with reduced gearshift comfort. Downshifts in deceleration state and deceleration downshifts are accomplished with intermediate throttle application and are thus very audible. Gearshifts are performance-oriented and the engine torque is not reduced during upshifts and downshifts. The vehicle moves off in 1st gear. 7th gear is not available. The racing start function is available. Adaptation of Gearshift Characteristics to Driving Style and Route Profile Various measured values, such as accelerator pedal position, accelerator pedal change speed, axial and lateral acceleration, vehicle speed and engine speed as well as the steering angle, are used to adapt the gearshift characteristics almost continuously to the driving style and route profile. This adaptation is performed in Normal mode (no sport buttons pressed) and sometimes in Sport mode. No adaptation is performed in Sport Plus mode. When this adaptation is selected, the shift programme not only takes the driving style into consideration, but also road resistance. Changes in road resistance are particularly noticeable when driving uphill and on downward slopes. In addition, the PDK control unit forms an altitude correction factor, i.e. since the volumetric efficiency of the engine decreases as the altitude increases, the driver automatically accelerates more and the transmission would switch to a more shift-conducive map. This is detected by the altitude sensor and the optimal map is made available to the driver. Special Functions Launch Control (racing start function) This function is available both in selector-lever position D and M in Sport Plus mode. Preconditions are as follows: Vehicle is stationary, brake is applied, kickdown is active. The function is triggered by releasing the brake. The Doppel kupplung in the transmission now enables optimum wheel slip at maximum acceleration. Stress on components increases significantly when driving off at maximum acceleration in comparison with driving off normally. In addition, there is a high temperature burden on the components in the clutches. To protect the components in this case, this function is disabled for a distance of 1.5 miles (2,5 km) after a racing start. During the 1.5 miles (2,5 km) drive, the clutches are cooled with the maximum cooling volume flow. Prevention of downshifts in overrun state, e.g. approaching a corner (Fast Off) If the driver decelerates, i.e. releases the accelerator pedal quickly, when approaching a corner, the currently engaged gear is retained. If the driver also actuates the brake now, downshifts adapted to the vehicle speed are performed so that engine braking support is available when approaching a corner and the vehicle can be accelerated out of the corner in the optimum gear. If the accelerator pedal is now moved towards throttle valve open again, gearshifts are performed once again according to the driver request. This function responds differently, depending on which mode was selected. If Normal mode is selected, the function is only activated for a high negative accelerator pedal gradient. In Sport mode, the function is activated for a medium negative accelerator pedal gradient, while it is activated for a low negative accelerator pedal gradient in Sport Plus mode. Downshifts while braking (Fast Back) A downshift is initiated immediately if the driver switches quickly (within approx. 1 second) from accelerating to braking. However, the sportiness characteristic and the selected mode dictate how early a downshift is initiated. Drivetrain Repair Sports Cars Page 7.7

76 PDK Transmission Special Functions (cont d) Gear retention while cornering The lateral-acceleration sensor (single component with rotation-rate sensor), which is located under the centre console and works for the PSM system, is used to detect lateral acceleration and retain the engaged gear and lateral acceleration in the relevant gear, depending on the shift map. Active switching to a sporty gear-changing map For increased spontaneity, the system switches to a sporty and dynamic shift map when the driver uses fast, positive accelerator pedal movements. The previous map is then activated again afterwards. This function is intended, for example, for situations in which a driver is driving at an extremely comfortable speed on a country road, but now decides to overtake and wants the vehicle to drive dynamically for a short time. Manual momentary intervention in selector-lever position D To enable manual downshifts even in the automatic gear-selection gate, e.g.: when approaching a corner when entering speed zones/small towns when driving downhill the upshift and downshift buttons (both on the steering wheel and on the selector lever) are active in the automatic gear-selection gate. In other words: PDK transmission switches to the manual program when the corresponding button is pressed. M appears in the instrument cluster and the requested gearshift is performed. At the same time, an 8-second timer is started in the control unit. If the upshift or downshift button is pressed again within this 8 seconds, the timer is restarted. The PDK transmission automatically switches back to Automatic mode ( D appears in the instrument cluster) if: the timer runs out, no cornering is performed and the vehicle is not in deceleration state the selector lever is moved from D to M and back to D Automatic upshifts and downshifts at the engine speed limits remian active. The deceleration downshift function is also active. Warm-up Program The warm-up map is a shift program with raised gearchanging points, which has the effect of heating the catalytic converters to their operating temperature as quickly as possible. Even the engine and transmission reach their operating tem pera ture more quickly with this map. The coolant temperature of the engine is checked when the engine is started. If this is less than approx. 68 F. (20 C), the warm-up program is activated and is deactivated again when the coolant temperature is 86 F. (30 C). Overheating Protection Various measures are implemented on the transmission in order to protect the transmission and Doppelkupplung from overheating. The temperature sensor, which is fitted above the hydraulic control unit and measures the oil sump temperature, is used for this purpose. A calculation model, which calculates the clutch temperature from the engine torque and the slip at the clutch, is also used. Overheating protection is activated in several stages and actively prompts the driver to adapt his driving style. Clearly perceptible jerking occurs in the first stage due to continuous opening and closing at drive-off and crawling speed, thereby prompting the driver to change the driving situation. Engine torque and kickdown rpm are also reduced. This is not displayed in the instrument cluster. A fault is stored in the control unit. If the temperature continues to rise, stage two is activated. This means that jerking continues. The engine torque and kickdown revs are reduced more drastically in this case. The white warning Transmission temperature too high appears in the instrument cluster and another fault is stored in the fault memory. If the temperature rises even further, the red warning Transmission emergency run appears in the instrument cluster. A short time later, the Doppelkupplung is opened completely and power transmission is no longer available. Another fault is stored in the fault memory. If the driver now presses the accelerator, the vehicle will drive off, but not with the usual level of comfort. After implementing these measures, the transmission activates a special shift program in which gear changes are performed very slowly, with a high level of discomfort. Once the temperature falls below a certain temperature threshold, the transmission reverts to its normal program. Page 7.8 Drivetrain Repair Sports Cars

77 PDK Transmission Upshift Suppression for 7th Gear 7th gear is designed as an overdrive on PDK transmissions. This means that in various driving situations, e.g. high road resistance, the vehicle would decelerate when 7th gear is engaged. As a result, 7th gear is not engaged in such situations. Upshift Interruption In automatic transmissions, the time that elapses between triggering a change in speed and starting to change speed is called the response time. Naturally, this response time depends on the shift program and the gearshift characteristic. During this time, the driver does not yet notice that the gearshift operation has already started. If the driver request changes, e.g. the driver quickly eases off the accelerator, the upshift that has started is interrupted provided the engine speed remains unchanged. One-touch Hold Function The one-touch button on the steering wheel or the selector lever must be held in a downshift ( ) or upshift direction ( + ) in order to engage the lowest or highest possible gear. Tipping the button back initially triggers the first gear change in accordance with the touch command. The next lower or next higher gear is then always engaged by holding the button. This saves the driver from having to touch the button repeatedly. This function is switched off after 25 seconds to prevent malfunctions. Drive-Off Assistant If the vehicle is stopped on an incline, the driver will apply the brake and set a certain brake pressure. When the driver now switches from the brake pedal to the accelerator pedal in order to drive off, the set brake pressure is maintained for as long as it takes for the vehicle to drive off. This prevents the vehicle from rolling back while the driver is switching pedals. Rollback prevention is enabled for max. 2 seconds. Tow-Starting/Towing The vehicle cannot be tow-started, nor should this be attempted due to the risk of serious transmission damage. When the engine is not running, adequate lubrication of the transmission is not guaranteed. Therefore the following points must be observed: 1. Engage selector-lever position N 2. Top speed = 30 mph (50 km/h) 3. Maximum towing distance = 30 miles (50 km) 4. In the case of long towing distances, all-wheel-drive 911 Carrera 4 vehicles must be transported on a flat bed tow truck. Notes: Crawling To ensure that the PDK transmission behaves in the same way as a Tiptronic transmission when driving off, clutch 1 is already slightly engaged so that the transmission becomes positively engaged and must be held by the brake. Another advantage of this measure is that the vehicle drives off very comfortably and generally smoothly when only a light load is applied. Driving off at a higher load results in higher drive-off power. Stationary Decoupling When the vehicle comes to a stop, the clutch is generally opened as long as the brake is applied. However, the clutch remains slightly engaged in order to take full advantage of crawling. The reason for this measure is reduced fuel consumption. Drivetrain Repair Sports Cars Page 7.9

78 PDK Transmission Basic Transmission In order to avoid unnecessary duplication, we ll use a 911 Carrera PDK transmission in this section. Gear Wheel Set 1 Loose gear wheel for 4th gear 2 Synchronizing hub with synchronization 3 Loose gear wheel for 6th gear 4 Spacer 5 Fixed gear wheel for 2nd gear 1 Drive shaft 1 2 Drive shaft 2 3 Main shaft 4 Pinion shaft 5 Intermediate gear wheel The illustration above shows the structure of input shaft 2 The gear wheel set in the transmission comprises input shaft 1 (1), input shaft 2 (2), the main shaft (3), the pinion shaft (4) and the intermediate gear wheel (5). 1st, 3rd, 5th, 7th and reverse gear are on input shaft 1, while 2nd, 4th and 6th gear are on input shaft 2. 1 Sensor wheel 2 Fixed gear wheel for reverse 3 Fixed gear wheel for 1st gear 4 Fixed gear wheel for 3rd gear 5 Loose gear wheel for 7th gear 6 Synchronizing hub with synchronization 7 Loose gear wheel for 5th gear 1 Fixed gear wheel for 4th gear 2 Spacer 3 Fixed gear wheel for 6th gear 4 Constant gear wheel 5 Bearing plate bearing 6 Loose gear wheel for 2nd gear 7 Synchronizing hub with synchronization 8 Loose gear wheel for reverse gear 9 Loose gear wheel for 1st gear 10 Synchronizing hub with synchronization 11 Loose gear wheel for 3rd gear 12 Fixed gear wheel for 7th gear 13 Spacer 14 Fixed gear wheel for 5th gear 15 Output flange The illustration above shows the structure of input shaft 1 Page 7.10 Drivetrain Repair Sports Cars

79 PDK Transmission Synchronization The direction change for reverse gear is accomplished via an intermediate gear wheel (1), which is located between input shaft 1 and the main shaft. 1 Bevel gear 2 Constant gear wheel 3 Parking-lock gear 1 Synchronizer ring 2 Ball 3 Clutch hub 4 Guide sleeve 5 Operating sleeve 6 Spring 7 Pressure piece 8 Loose gear wheel Basic operating principle of servo-lock synchronization Synchronization in neutral position. The ball (2) holds the operating sleeve (5) in neutral. When changing gears, the operating sleeve (5) is moved (to the left in the example shown) using the shift fork of the selected gear. The operating sleeve presses the synchronizer ring (1) against the friction cone of the clutch hub (3) via the pressure piece (7). At this moment, the synchronizer ring turns until it reaches a stop (not shown in the illustration). This blocks the movement of the operating sleeve. Drivetrain Repair Sports Cars Page 7.11

80 PDK Transmission Synchronization of Reverse, 1st, 2nd and 3rd Gear The synchronizer ring (1) continues to block the operating sleeve for as long as there is a difference in speed between the clutch hub (3) and operating sleeve. The synchronizer ring can only be turned back through the operating sleeve when the speed is the same. The latter is then moved on slightly to the clutch hub. The gear is engaged. 1 Synchronizer ring 2 Friction cone for loose gear wheel 3 Intermediate ring 4 Inner ring Triple cone synchronization is used for reverse, 1st, 2nd and 3rd gear. The use of three friction cones has resulted in a considerable reduction in synchronizing forces. This reduces shifting forces when engaging gears. The first friction cone comprises the friction cone of the clutch hub of the loose gear wheel (2) and the inner cone of the inner ring (4). The second friction cone comprises the outer cone of the inner ring (4) and the inner cone of the intermediate ring (3). The third friction cone comprises the outer cone of the intermediate ring (3) and the inner cone of the synchronizer ring (1). Synchronization of 4th, 5th, 6th and 7th Gear 1 Synchronizer ring 2 Friction cone for loose gear wheel Single cone synchronization is used for 4th, 5th, 6th and 7th gear. The cones from the clutch hub (2) and the cones of the synchronizer rings (1) form the friction cone. Page 7.12 Drivetrain Repair Sports Cars

81 PDK Transmission Final Drive and Differential Shifting The shift rods are actuated hydraulically and are used to switch the synchronizers and therefore to change gears. They transfer the shifting forces generated in the actuator hydraulics to the actuating elements for synchronization. Each shift rod actuates two synchronizers and two gears. Once the gear is engaged, the shift rod is depressurized. The gear is held securely and without strain by detent in traction/deceleration mode by the form fit of the toothing. 1 Cover 2 Flange 3 Ring gear 4 Differential 5 Pinion shaft The illustration above shows the position of the final drive in the transmission. 1 Shift rod for gears 4 and 6 2 Shift rod for gears 5 and 7 3 Shift rod for gears 1 and 3 4 Shift rod for gears 2 and reverse A Shift rod B Magnet C Shift fork 1 Ring gear 2 Differential pinions 3 Shaft bevel gears 4 Planet-gear carrier 5 Discs 6 Pinion The shift rods are in neutral and the end positions are locked. Shift travel from neutral into the locked engage positions of the gears is nominally the same for all shift rods. The mechanical neutral position is nominally 0 mm shift travel, in accordance with the characteristic of the transmission distance sensors. Each shift rod has a sensor magnet for recording shift travel via the transmission distance sensors. The final drive is designed as a hypoid drive. A limited-slip differential with a lock value of 22% in traction and 27% in deceleration is available as optional equipment instead of the standard differential. Drivetrain Repair Sports Cars Page 7.13

82 PDK Transmission Locking The shift rods in a transmission are locked against each other. In transmission 1, shift rod 3 (1st/3rd gear) is locked against shift rod 2 (5th/7th gear). In transmission 2, shift rod 1 (4th/6th gear) is locked against shift rod 4 (2nd/reverse gear). Reverse gear is also locked against all forward gears. 1 Selector shaft 2 Parking-lock gear 3 Catch Parking Lock Even if the vehicle is in gear, it cannot be prevented from rolling back in the same way as on a manual transmission because the clutches are opened in a depressurized state and threfore do not stop the vehicle from moving. The parking lock prevents the vehicle from rolling away, as with an automatic transmission. When the vehicle is stationary, the parking lock is engaged (purely mechanically) using the selector lever and blocks the pinion shaft via a catch, which engages in the toothing of the parking-lock gear. The final drive is blocked in this way. 1 Detent spring 2 Selector shaft 3 Detent disc 4 Connecting rod 5 Catch 6 Leg spring 7 Parking-lock gear Notes: Page 7.14 Drivetrain Repair Sports Cars

83 PDK Transmission Power Flow The torques are transferred either via clutch 1 or 2. Clutch 1 drives input shaft 1 (inner input shaft) and clutch 2 drives input shaft 2 (outer input shaft). Gears 1, 3, 5, 7 and reverse are on input shaft 1, while gears 2, 4 and 6 are on input shaft 2. Power flow for 5th gear Power flow for 1st gear Power flow for 6th gear Power flow for 2nd gear Power flow for 7th gear Power flow for 3rd gear Power flow for reverse gear Power flow for 4th gear Drivetrain Repair Sports Cars Page 7.15

84 PDK Transmission Dual-mass Flywheel The engine torque is routed into the clutches via a dualmass flywheel. Doppelkupplung The wet dual clutch or Doppelkupplung is a central module of the PDK transmission. With its wide range of technical features, it meets the functional requirements of the transmission control system, thereby shaping the special character of this transmission concept. Very fast response times, low inertia and good, comfortable friction values, combined with good economic viability allow both very sporty driving with highly dynamic gear changing as well as comfortable cruising. For safety reasons, the clutches are opened when they are depressurized and inactive. The radial arrangement of the disc packs provides the best combination from the point of view of performance and space. Function The Doppelkupplung is positioned directly on the transmission input. It transfers the engine torque from the dualmass flywheel via the profile of its input shaft and passes it through the housing cover of the dry chamber into the wet chamber and on to the clutch primary. The disc packs are arranged radially over each other. The clutch sends the torque either to the odd gears 1st, 3rd, 5th and 7th and to reverse gear via the outer disc pack, or to the transmission with 2nd, 4th and 6th gear via the inner disc pack, depending on which of the two is activated by the control pressure of the hydraulic transmission control system. The torque is routed into the two transmissions via the profiles of the transmission input shafts. 1 Outer disc carrier (engine speed) 2 Disc pack, transmission 2 3 Hydraulic actuation, transmission 2 4 Input shaft, transmission 2 5 Connection to engine 6 Input shaft, transmission 1 7 Hydraulic actuation, transmission 1 8 Disc pack for transmission 1 Careful selection of pad type, pad dimensions and usage as well as uniform distribution of thermal load and oil flow in the disc pack, along with the corresponding oil types, are prerequisites for comfort and performance over the service life. Low drag torques even at low temperatures as well as good resistance at high speeds guarantee comfort and excellent sportiness, but are also important safety requirements. Special hydraulic oil is used for actuating the Doppelkupplung hydraulically and for cooling the clutch. This oil is also used for shifting gears. PDK has a separate oil circuit for lubricating the gear wheel set and for cooling. This oil must not be mixed with hydraulic oil. Both clutches can be actuated and operated with slip regulation independently of each other. Both clutches display slight centrifugal force overcompensation. The Doppelkupplung is not fully slip-regulated in any operating state, which means that the vehicle must be held with the brake when in gear to prevent it from rolling away. Page 7.16 Drivetrain Repair Sports Cars

85 PDK Transmission Clutch Cooling The clutches are cooled with a separate oil flow to prevent them from overheating. Clutch cooling and clutch control are activated at the same time. The cooling oil flow is regulated by a control valve on the hydraulic control unit. K1 Cooling duct for clutch 1 K2 Cooling duct for clutch 2 Q_kühl Cooling duct cross-section (regulated) 0 Cooling duct closed 1 Centering bore B 2 Locking groove 3 Pass-through screws, 20 ea. 4 Centering bore 5 Tension point 6 Oil discharge for temperature sensor 7 Pressure regulator 8 Solenoid valves Hydraulic Control The hydraulic switching device performs the following tasks: Controls the system and reducing pressure Supplies oil to the actuators, clutches, actuating cylinders, cooling system and lubrication system Activates the clutches and actuating cylinders Provides emergency hold functions during mechanical transmission emergency operation Controls the parking lock hydraulically 1 Tension point 2 Port plate 3 Intermediate plate 4 Valve housing 5 Bolts in hydraulic switching device, 22 x M6 6 Through bolts, 20 x M6 7 Retaining bracket 8 Solenoid valves 9 Pressure regulator The hydraulic system is installed in the oil pan area in the transmission. Drivetrain Repair Sports Cars Page 7.17

86 PDK Transmission Hydraulic Control (cont d) Oil Cooler The oil cooler (1) is fitted on the outside of the transmission. It cools the clutch fluid and hydraulic oil, which is heated up significantly more than gear-wheel oil as a result of operating the clutch (frictional heat). 1 Solenoid valves, 2 ea. 2 Solenoid valve 1 3 Solenoid valve 2 4 Gear valve 2, EDS5 5 Gear valve 1, EDS6 6 Pressure-reducing valve 7 Clutch valve 1, EDS1 8 Clutch valve 2, EDS2 9 Clutch selector valve, EDS3 10 Pressure control valve, EDS3 11 Switch-over valve 12 Pressure regulator, 6 ea. 13 Cooling valve 14 System-pressure valve 15 Pressure control valve (cooler) 16 Cylinder selection valve 1 17 Transmission selection valve 18 Cylinder selection valve 2 1 Oil cooler (oil/water heat exchanger) 2 Cooler supply line 3 Cooler return line The top pipeline (2) is the cooler supply line, while the bottom pipeline (3) is the cooler return line. The gear-wheel oil is cooled sufficiently by the transmission housing. Page 7.18 Drivetrain Repair Sports Cars

87 PDK Transmission Sensors The following sensors are used in the transmission for recording speed, temperature, pressure and distance signals. 4 distance sensors (combined in one housing) 2 rpm or speed sensors (combined in one housing) 2 pressure sensors 1 temperature sensor The distance and speed sensors are connected by a wire harness and are guided outward via the 16-pin transmission connector. The pressure sensors (2) are connected to the wire harness, to which the solenoid valves and pressure adjusters are connected. The temperature sensor (3) is connected permanently to the wire harness. This is guided out of the transmission via a 20-pin connector. The sensors are all located in the transmission. Sensors cannot be removed or installed from outside. Distance Sensors The distance sensor unit (also called sensor tower ) is used for recording the position of each individual shift rod (1). It is designed as an assembly, made up of 4 integrated absolute distance sensors. 1 Speed sensors 2 Pressure sensors 3 Temperature sensor 4 Distance sensors The transmission has two separate wire harnesses due to the design with two chambers with different fluids. A 16 pin harness is installed in the section with gear lube (Mobilube PTX Formula A SAE 75W 90) and a 20 pin harness in the section with hydraulic oil (Pentosin Gear Oil FFL3). Each shift rod (1) is assigned a sensor, which converts the linear movement of the shift rod into a distance-proportional PWM signal. Other functional components of the distance sensor unit include four associated sensor magnets (2) on the shift rods. The supply voltage for the distance sensors is 5 V. The diagnostic system checks the sensor as follows: Short circuit to ground Short circuit to supply voltage Open circuit in line Signal plausibility Notes: Drivetrain Repair Sports Cars Page 7.19

88 PDK Transmission Speed Sensors The speed sensors (1) record the transmission input speeds and rotation directions for input shaft 1 and 2. They are designed as an assembly made up of two individual speed sensors in one housing. The pickup or sensor wheel (2) records the speed of input shaft 1, while the fixed gear wheel for 2nd gear records the speed of input shaft 2. A coded PWM signal is generated as the output signal. Pressure Sensors The two pressure sensors (1) for measuring the clutch pressure values of the two Doppelkupplung clutches are read directly at the rotary transmission feed-through point. They are fitted in the centering plate and are connected to the wire harness (3) by connectors (2). The supply voltage is 5 V. The diagnostic system checks the sensor as follows: The supply voltage for the speed sensors is 8.5 V. The diagnostic system checks the sensor as follows: Short circuit to ground Short circuit to supply voltage Open circuit in line Signal plausibility Short circuit to ground Short circuit to supply voltage Open circuit in line Signal plausibility Temperature Sensor The temperature sensor is used to record the sump temperature of the hydraulic oil. This involves measuring a temperature-dependent resistance. The supply voltage is 5 V. The diagnostic system checks the sensor as follows: Short circuit to ground Short circuit to supply voltage Open circuit in line Signal plausibility Page 7.20 Drivetrain Repair Sports Cars

89 PDK Transmission Electronic Transmission Control PDK Shift-Lever The transmission control unit is connected to other control units in the vehicle via the CAN bus. Instrument Cluster PDK DME Steering Wheel/ Steering Column Control Unit Gateway Selector Lever PSM Front Control Unit Interfaces in the Control Unit Network The control unit receives information about the driver request, which includes the following: Selector-lever position Sport button and/or Sport Plus button Accelerator pedal position Brake signal In addition, the operating state of the vehicle is also included: The new PDK Selector lever is a shift by wire concept (There is no mechanical connection between the shift lever and the transmission with the exception of the mechanical park lock.) The PDK selector lever has 2 microcontrollers and 2 Hall sensors to detect the lever position (redundant position sensing). The main communications interface is by CAN drive train bus with the serial bus as a redundant function. The Selector lever lock for key and shiftlock is controlled by the PDK control unit. Wheel speeds Vehicle speed Road resistance Axial and lateral acceleration Altitude factor Engine and transmission speed Engine and transmission temperature These input values are processed in the driving software and the driver request is executed, depending on the shift program and driver type detection. Control Unit Location 911 Carrera (997) The transmission control unit is located at the left behind the door in the sill area. Boxster/Cayman (987) The transmission control unit is located in the rear right of the luggage compartment beneath the cover. Drivetrain Repair Sports Cars Page 7.21

90 PDK Transmission PDK Shift-Lever Interface Engine off: Serial line is used for communication (gear position from instrument cluster). Engine running: CAN bus is utilized for communication. Instrument Cluster Gateway CAN Drive Serial Communication Shift Lever Control Unit Control For Key/Shift Lock Transmission Control Unit Mechanical Linkage For Park Lock Notes: Page 7.22 Drivetrain Repair Sports Cars

91 Final Drive Setup Subject Page Adjusting Drive Pinion Set Boxster Adjusting Drive Pinion Set 911 Turbo (993) Drivetrain Repair Sports Cars Page 8.1

92 Final Drive Setup Notes: Page 8.2 Drivetrain Repair Sports Cars

93 Final Drive Setup Boxster Adjusting Final Drive Boxster G 86 General Careful adjustment of the pinion shaft and ring gear are crucial to the service life and smooth running of the final drive. Therefore, pinion shafts and ring gears are paired with each other during the manufacturing process and are checked by special inspection machines to ensure that the tooth contact is in the optimum position and that there is low noise in both rotation directions. The deviation r referred to the master gauge R o is measured for the drive sets supplied as spare parts and is recorded on the outer circumference of the ring gear. Every drive set (ring and pinion) must be replaced as a set. Adjustment and Marking of the Drive Sets (G 86) Drive Sets Installed In New Vehicles Note In the series, the position of the pinion shaft is determined by the dimension P o (center of the ring gear to the rear of the pinion shaft head). The markings of the deviation r on the ring gear and the pairing number are not present. Due to the deviation r not being given, it is necessary that, before the pinion shaft is replaced, to carry out an actual measurement if the parts are being replaced which directly influence the installation position of the pinion shaft. X These details are not required in the series. P o Adjustment dimension for the series. KD Drive Sets Notes: 1. Identification 0937 means Oerlikon drive set with the transmission ratio of 35:9. 2. Pairing number (312) of the drive set. 3. Deviation r referred to the master gauge of the special inspection machine used in production. The deviation r is always stated in 1/100 mm. Example: 25 means r = 0.25mm. R o Length of the used master gauge of the special inspection machine. R o = mm R Actual dimension between the ring gear axis and the front side of the pinion shaft at the point of maximum smooth running for this drive set. V o Hypoid offset. Drivetrain Repair Sports Cars Page 8.3

94 Final Drive Setup Boxster Adjustment Overview When carrying out assembly work on the final drive, readjustment of the ring and pinion is necessary only if parts are being replaced which directly influence the adjustment of the final drive. In order to avoid unnecessary adjustment work, observe the following chart: * If the transmission housing is replaced, it is also necessary to adjust the input shaft. Notes: Page 8.4 Drivetrain Repair Sports Cars

95 Final Drive Setup Boxster Appropriate Sequence For Readjusting Drive Set Determining The Installation Position Of The Pinion Shaft (Actual Measurement) This procedure must be carried out only if the deviation r is not given on the ring gear and if parts are to be replaced which directly influence the pinion shaft position. These are: both tapered roller bearings for the drive pinion and the transmission housing. Remove the differential, complete the universal measuring mandrel, as described in the Boxster Technical Manual Insert it into the transmission housing and measure the difference to R o (max. deflection/reversing point). The measured value corresponds to the deviation r. Note the value. S1 = Adjusting shim for ring gear S2 = Adjusting shim for ring gear S3 = Adjustment shim for pinion shaft S4 = Adjustment shim for pinion shaft If the pinion shaft and ring gear have to be adjusted, it is best to follow the following sequence: After replacing the parts, adjust the pinion shaft as described. When doing so, use the deviation r determined when measuring the adjusting shim S3. Notes: 1. Determine the total disc thickness Stot )S1 plus S2) for the correct preload of the tapered roller bearings - differential. 2. Determine the total disc thickness Stot (S3 plus S4) for the correct preload of the tapered roller bearings - pinion shaft. 3. Divide up the total disc thickness Stot in S3 and S4 so that the measurement from the ring gear center to the front of the drive pinion corresponds to the installation dimension R measured during production. 4. Divide up the total disc thickness Stot in S1 and S2 so that the stipulated circumferential backlash is present between the ring gear and pinion shaft. The goal of the adjustment is to again achieve the position of maximum smooth running which was determined in production on the testing machine. The greatest possible care and cleanliness during the assembly process are required to assure adjustment accuracy. Drivetrain Repair Sports Cars Page 8.5

96 Final Drive Setup 911 Turbo (993) Adjusting Final Drive 911 Turbo (993) In this section we cover final drive setup using a 911 Turbo (993) model. This information is general and intended to demonstrate proper technics and tools when installing and setting up a differential. All the specifications and processes listed in this section are for training purposes only. Always consult the individual model s technical manual when performing final drive setup. The Porsche Special Tools listed in this section are noted in Bold type (example 9150). Information regarding Porsche Special Tools can be found in the Special Tool Catalog, part number, PNA General The settling of drive pinion and ring gear is a determining factor for the service life and smooth running of the rearaxle drive. Drive pinions and ring gears that have been checked for good tooth contact pattern and low noise in both directions of rotation on special test equipment are therefore matched during production. The position at which smoothest running can be achieved is determined by shifting the drive pinion axially, whereby the ring gear is kept within the tolerance of the prescribed tooth backlash and is engraved on ring gear as setting dimension E. Ring and Pinion Values E = Design dimension 1 = Setting dimension E (e.g mm) 2 = Circumferential backlash F (e.g mm) 3 = Matching number Adjusting Drive Pinion Setting value E (70.32 mm) Final Drive Adjustment Points 1 - Shim S Shim S Adjusting shim S 3 E - Setting value Correct results may only be achieved if assembly work and measuring procedures are carried out carefully and with maximum cleanliness. Notes: The 1 Setting Value E Is Indicated On The Ring Gear. 1. Install complete gear set without S 3 shims and tighten all tensioning plate hexagon-head nuts to 23 Nm (17 ftlb.). 2. Fit gear housing and locate with three nuts. 3. Install and engage sixth gear. 4. Block input shaft with Special Tool 9253 and tighten drive pinion collar nut to 300 Nm (221 ftlb.). Page 8.6 Drivetrain Repair Sports Cars

97 Final Drive Setup 911 Turbo (993) Adjusting Drive Pinion (cont d) Suitable Pipe Section (A) 5. Set adjusting ring of measuring mandrel VW 385/1 to dimension a. 9. Fit lateral transmission cover without O-ring and tighten crosswise with 4 nuts. Note: Do not use a hammer when fitting the lateral transmission cover (the gauge block plate held by magnets might fall off). Fit cover in installation position only by tightening the nuts uniformly. Notes: A = approx. 65 mm 6. Assemble measuring mandrel with centering disks 9109, tapered roller bearing, plunger VW 385/14 and dial gauge extension Set special tool measuring mandrel with master gauge 385/30 to the setting value (61.43 mm in the example). Set dial gauge (3 mm measuring range) to zero with 1 mm preload. 8. Put gauge block plate 9281 on drive pinion head and insert measuring mandrel into transmission case. Dial gauge extension is located in the area of the gauge block plate. Drivetrain Repair Sports Cars Page 8.7

98 Final Drive Setup 911 Turbo (993) Adjusting Drive Pinion (cont d) 10. Pull second centering disk with spindle towards the outside until the measuring mandrel can just be turned by hand. Adjusting Ring Gear Determine total shim thickness S tot. (S 1 + S 2 ). The ring gear must be adjusted, if the: Transmission case, lateral transmission cover, tapered roller bearing for differential, differential housing or drive set have not been replaced. Note: The drive pinion must be removed to determine the preload of the differential tapered roller bearings. 1. Make sure that the bearing outer races of the tapered roller bearings are well seated in the transmission case or lateral transmission cover, respectively. 2. Fit one spacer ring (2.5 mm thick) on the ring gear side and on the opposite side of the differential to be used. 11. Turn measuring mandrel carefully until the dial gauge extension is vertical to the face of the drive pinion head. At this point, the pointer of the dial gauge reaches maximum deflection (reverse point) and the dial gauge must be read. Note: The measured value always deviates from the set dimension clockwise (the smaller pointer on the dial gauge is between 1 and 2), i.e. if the dial gauge is set with a preload of 1 mm, the value deviating from 1 is taken as shim thickness S Insert differential into transmission case and rotate several times. 4. Fit lateral transmission cover without seal and tighten all hexagon-head nuts to 23 Nm (17 ftlb.). 5. Put gauge block plate VW 385/17 on the collar of the differential. 6. Fasten universal dial gauge holder VW 387 with dial gauge and extension to the case and set to 0 with 2 mm preload. Example: If the small pointer on the dial gauge is between 1 and 2 and the large pointer indicates 0.37 mm, then 0.37 mm is the shim thickness (with 1 mm gauge preload) to be inserted. Always round up or down to the nearest 0.05 mm (e.g mm to 0.35 mm). 12. After inserting the necessary shims, check the setting value E again. A deviation of ± 0.03 mm is permissible. A = Dial gauge extension (approx. 30 to 40 mm long) B = Gauge block plate VW 385/17 7. Move differential up and down. Read off backlash on the dial gauge and note. Note: Do not turn differential while measuring backlash as this will give an incorrect reading. Page 8.8 Drivetrain Repair Sports Cars

99 Final Drive Setup 911 Turbo (993) Adjusting Ring Gear (cont d) 8. Calculate S tot.. S tot. = Fitted shim thickness + Measured value + Pressure fit of tapered roller bearing Example Thickness of shims inserted 5.00 mm Measured value 0.75 mm Pressing (constant value) 0.40 mm S tot mm 9. Remove differential, pull off both tapered roller bearings and split calculated shim thickness S tot. as follows. Select spacer S mm thinner and S mm thicker as a starting point for subsequent adjustment of the backlash. Example: Total shim thickness of spacers S 1 + S 2 = 6.15 mm Thickness of spacer S mm = mm mm mm Thickness of spacer S mm = mm mm mm Note: Spacers are available in thicknesses of 1.6 to 3.1 mm in increments of.010 mm. By using a 0.25 mm shim, the shim thicknesses may be graduated in increments of 0.05 mm, Adjusting Circumferential Backlash Note: The backlash to be set is embossed on the ring gear. 1. Mount gear set using shims S 3 determined while adjusting the drive pinion. Note: Make sure that the collar nut of the drive pinion is tightened to 300 Nm (221 ftlb.) before measuring backlash. 2. Insert differential with tapered roller bearing and shims (S 1 + S 2 ) into the housing. 3. Fit lateral transmission cover and tighten all hexagonhead nuts to 23 Nm (17 ftlb.). Note: Always make sure that there is a certain amount of backlash when tightening the nuts. Never allow the drive pinion to seize. 4. Assemble measuring lever VW 388 and adjusting device VW 521/4 and adjust lever length to 91 mm with the plunger. Refer to dimension a in the illustration. 5. Insert adjusting device with clamping sleeve 9145 into the differential and clamp firmly. 6. Rotate differential in both directions several times to settle the tapered roller bearings. 7. Fit universal dial gauge holder with flat extension in such a way as to produce a right angle between dial gauge axis and lever. The calculated shim thicknesses must be rounded up or down for plausible dimensions that will not alter the total thickness S 1 and S 2. Example: Calculated thicknesses S 1 + S 2 = = 6.15 mm Rounded thicknesses S 1 + S 2 = = 6.15 mm Measure shims with a micrometer in several places. Permissible deviation 0.02 mm. Also check shims for burrs and damage. Dimension a = approx. 91 mm Drivetrain Repair Sports Cars Page 8.9

100 Final Drive Setup 911 Turbo (993) 8. Turn ring gear carefully at the clamping screw of the adjusting device as far as the stop and set the dial gauge to zero. Turn back ring gear and read off circumferential backlash. Write down the reading. Notes: Note: When carrying out measurements, the drive pinion must be blocked with Special Tool After turning the ring gear a further 90 repeat measuring procedures three times. The measured values must not deviate from one another by more than 0.05 mm. Note: The backlash to be adjusted is embossed on the ring gear. A deviation of ± 0.03 mm is admissible. 10. If the required backlash cannot be obtained, replace spacers (S 1 + S 2 ) again. The total shim thickness ( S tot. ) must not be altered, however. Page 8.10 Drivetrain Repair Sports Cars

101 Conversion Charts Temperature Conversion Metric Conversion Formulas INCH X 25.4 = MM MM X.0394 = INCH MILE X = KILOMETER(KM) KM(KILOMETER) X.621 = MILE OUNCE X = GRAM GRAM X.0352 = OUNCE POUND(lb) X.454 = KILOGRAM(kg) kg(kilogram) X = lb(pound) CUBIC INCH X = CUBIC CENTIMETER(cc) cc(cubic CENTIMETER)..... X.061 = CUBIC INCH FOOTPOUND(ft lb)..... X = NEWTON METER(Nm) Nm(NEWTON METER)... X.7376 = ft lb(foot POUND) HORSEPOWER(SAE).... X.746 = KILOWATT(Kw) HORSEPOWER(DIN).... X.9861 = HORSEPOWER(SAE) Kw(KILOWATT) X 1.34 = HORSEPOWER(SAE) HORSEPOWER(SAE)... X = HORSEPOWER(DIN) MPG(MILES PER GALLON)... X.4251 = Km/l(KILOMETER PER LITER) BAR X 14.5 = POUND/SQ. INCH(PSI) PSI(POUND SQUARE INCH)... X.0689 = BAR GALLON X = LITER LITER X.2642 = GALLON FAHRENHEIT = CELSIUS CELSIUS X = FAHRENHEIT Drivetrain Repair Sports Cars Page 9.1

102 Conversion Charts Notes: Page 9.2 Drivetrain Repair Sports Cars

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