Single reduction Differential Carrier Series 7 - MS15 - MS16 - MS17 - MR15 Revised April 2003

an ArvinMeritor brand Maintenance manual no. MM-0140 Single reduction Differential Carrier Series 7 - MS15 - MS16 - MS17 - MR15 Revised April 2003

Table of contents pg. 05 Section 1: Introduction 06 Description 06 Specifications and data 07 Single reduction differential carrier standard version MS16-MS17 08 Single reduction differential carrier curvic version MS16-MS17 09 Single reduction differential carrier curvic version MS15-MR15 10 Exploded view standard version MS16-MS17 11 Parts list standard version MS16-MS17 12 Exploded view curvic version MS16-MS17 13 Parts list curvic version MS16-MS17 14 Exploded view curvic version MS15-MR15 15 Parts list curvic version MS15-MR15 17 Section 2: Maintenance 18 Single reduction differential carrier: removal and installation 19 Repairing the single reduction differential carrier 27 Installing the one-piece spigot bearing on the drive pinion with snap ring 29 Calculating thickness of shim pack 33 Hypoid gear set - tooth contact patterns 38 Lock nut sensor switch 39 Replacing pinion-pac seal 41 Torque chart 43 Section 3: Troubleshooting 2 ArvinMeritor Differential Carrier Series 7

Service Notes Before You Begin This publication provides installation and maintenance procedures for the Single Reduction Differential Carrier Series 7 MS15-MS16- MS17-MR15, produced by ARVINMERITOR HVS The information contained in this publication was current at the time of printing and is subject to revision without notice or liability. You must understand all procedures and instructions before you begin maintenance and service procedures. Access Information on ArvinMeritor's Web Site Additional maintenance and service information for ArvinMeritor's commercial vehicle systems component lineup is also available at www.arvinmeritor.com. To access information, click on Products & Services/Tech Library Icon/HVS Publications. The screen will display an index of publications by type. You must follow your company's maintenance and service guidelines. You must use special tools, when required, to avoid serious personal injury and damage to components. Meritor uses the following notations to alert the user of possible safety issues and to provide information that will help to prevent damage to equipment and components. WARNING A WARNING indicates a procedure that you must follow exactly to avoid serious personal injury. CAUTION A CAUTION indicates a procedure that you must follow exactly to avoid damaging equipment or components. Serious personal injury can also occur. NOTE: A note indicates an operational, procedure or instruction that is important for proper service. A NOTE can also supply information that will help to make service quicker and easier. This symbol indicates that you must tighten fasteners to a specific torque. Information contained in this publication was in effect at the time the publication was approved for printing and is subject to change without notice or liability. ArvinMeritor Commercial Vehicle Systems reserves the right to revise the information presented to discontinue the production of parts described at any time. ArvinMeritor Differential Carrier Series 7 3

Terms used in this manual Manufacturer: ARVINMERITOR Manual: Maintenance manual no. MM-0140 Device: Single Reduction Differential Carrier Series 7 - MS15 - MS16 - MS17 - MR15 Technician: Qualified personnel working on differential maintenance and servicing. Maintenance and servicing: Maintenance and servicing refer to periodical checks and/or replacement of differential parts or components. It also refers to the determining of the cause of a malfunction in order to restore the initial operating conditions. Operator: Any person who will use the differential as part of a more complex device.. Warranty Warranty applies to the differential unit installed on vehicles for which it was designed. Warranty is void in the following cases: Improper use of the vehicle on which the differential is installed (usage conditions, overloading etc.) Tampering with vehicle components that may affect rear axle performance. Use of non-original spare parts. Improper installation, adjustment, repair or modification. Poor or improper maintenance (including consumables other than those specified). Further information on warranty conditions may be obtained directly from the manufacturer or by referring to the ArvinMeritor web site at www.arvinmeritor.com 4 ArvinMeritor Differential Carrier Series 7

Introduction 1 pg. 06 Description 06 Specifications and data 07 Single reduction differential carrier standard version MS16-MS17 08 Single reduction differential carrier curvic version MS16-MS17 09 Single reduction differential carrier curvic version MS15-MR15 10 Exploded view standard version MS16-MS17 11 Parts list standard version MS16-MS17 12 Exploded view curvic version MS16-MS17 13 Parts list curvic version MS16-MS17 14 Exploded view curvic version MS15-MR15 15 Parts list curvic version MS15-MR15 ArvinMeritor Differential Carrier Series 7 5

1 Introduction General description The differential unit is of the single-reduction type featuring a hypoid gear set. The bevel pinion is mounted on two taper roller bearings (pinion unit) and a third straight roller bearing. The bevel pinion setting relative to the drive gear can be adjusted by varying the thickness of the shim pack located between the differential carrier and the pinion bearing cage. The differential gear case is supported on two taper roller bearings and is adjusted for end play through two threaded ring nut adjusters. The Series 7 MS15 - MS16 - MS17 - MR15 differential unit is available in two models: without differential lock with differential lock both in the STANDARD version with longitudinal clutch and CURVIC version with frontal clutch. Specifications and data Hypoid pinion bearings 2, taper roller (pinion-pac) and 1 straight roller bearing Differential unit Final drive hypoid MS16-MS17 Fine Pitch 2.80; 2.93; 3.07; 3.21; 3.42; 3.73 gear ratio 4.1; 4.30; 4.56; 4.89; 5.13; 5.63; 6.14 MS16-MS17 Coarse Pitch 2.85; 3.08; 3.10; 3.36; 4.11; 4.63; 5.29 MR15-MS15 Coarse Pitch Pinion to drive MS16-MS17 mm 0.26-0.50 gear backlash MR15-MS15 mm 0.20-0.45 Pinion to crown backlash adjustment Pinion to crown backlash adjustment 2.43; 2.57; 2.83; 3.09; 3.40; 3.78; 4.13 4.50; 5.14; 5.67 by adjusting rings by shims Differential bearing cap divergence mm 0.15-0.33 Differential bearing cap divergence adjustment by ring nut adjusters Differential idle pinion and side Nm 68 max gear assembly revolving torque Kgm 6.8 max Thickness range for shims fitted between bevel pinion bearing mm 0.125-0.200-0.500 cage and differential carrier Drive gear rest face runout on case half mm 0.13 max 6 ArvinMeritor Differential Carrier Series 7

1 Introduction Section through Standard single reduction differential carrier unit - type MS16-MS17 Fig. 1 ArvinMeritor Differential Carrier Series 7 7

1 Introduction Section through Curvic single reduction differential carrier unit - type MS16-MS17 Fig. 2 8 ArvinMeritor Differential Carrier Series 7

1 Introduction Section through Curvic single reduction differential carrier unit - type MS15-MR15 Fig. 3 ArvinMeritor Differential Carrier Series 7 9

Exploded view Standard version - Single reduction differential carrier - type MS16-MS17 48 49 50 13 8 9 10 11 12 28 22 31 7 1 21 45 19 46 3 2 15 7 3 5 20 16 33 6 4 30 5 6 25 24 26 27 29 model without differential lock 53 56 52 51 55 54 34 18 25 14 5 27 23 26 24 25 25 37 36 35 17 44 38 39 41 40 42 43 19 32 21 47 Fig. 4

Parts list Ref Description Ref Description 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 Carrier Bearing cap L.H. Pin Bearing cap R.H. Bearing cap washer Bearing cap capscrew Identification plate Pinion bearing cage O-ring (pinion cage) Pinion cage shim Pinion cage shim Pinion cage shim Pinion cage capscrew Plain half diff case Diff bearing cup L.H. Diff bearing cone L.H. Diff bearing cup R.H. Diff bearing cone R.H. Adjusting ring Diff case screw Cotter pin Plug Diff spider Diff pinion Diff pinion thrust washer Diff side gear Side gear thrust washer Drive pinion Drive gear 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 Ref. 51 52 53 54 55 56 Flange half diff case Pinion spigot bearing Drive pinion nut Drive gear screw Shift fork Shift fork pin Shift shaft Shift shaft spring Piston Piston O-ring Cylinder end cover Cylinder cover gasket Cover capscrew Cover capscrew washer Plug Sensor switch Lock-nut sensor switch Cluth collar Companion flange Deflector Pinion-pac seal model without differential lock End cover Sensor switch hole blanking plug Washer plug End cover capscrew End cover capscrew washer End cover gasket ArvinMeritor Differential Carrier Series 7 11

Exploded view Curvic version - Single reduction differential carrier - type MS16-MS17 MS16 - MS17 57 55 56 13 8 9 10 11 12 32 26 35 23 24 1 21 25 49 19 50 3 2 15 20 5 16 7 3 37 6 4 34 5 6 31 29 28 33 29 27 30 29 model without differential lock 60 59 58 61 63 62 38 41 42 43 40 39 18 17 14 31 30 28 29 48 44 46 45 47 52 53 54 36 51 22 19 Fig. 5

Parts list Ref Description Ref Description 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 Carrier Bearing cap L.H. Pin Bearing cap R.H. Bearing cap washer Bearing cap capscrew Identification plate Pinion bearing cage (pinion-pac) O-ring (pinion cage) Pinion cage shim Pinion cage shim Pinion cage shim Pinion cage capscrew Plane half diff case Diff bearing cup L.H. Diff bearing cone L.H. Diff bearing cup R.H. Diff bearing cone R.H. Adjusting ring Diff case screw Cotter pin Pin spirol Plug Thrust screw Wear pad Thrust screw nut Diff spider Diff pinion Diff pinion thrust washer Diff side gear Side gear thrust washer Drive pinion Drive gear 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 Ref. 58 59 60 61 62 63 Flange half diff case Pinion spigot bearing Drive pinion nut Drive gear screw Shift fork Shift fork pin Shift shaft Shift shaft spring Piston Piston O-ring Cylinder end cover Cylinder cover gasket Cover capscrew Cover capscrew washer Plug Sensor switch Lock nut-sensor switch Clutch collar Fixed collar Spacer Retaining ring Companion flange Deflector Pinion pac-seal model without differential lock End cover Sensor switch hole blanking plug Washer plug End cover capscrew End cover capscrew washer End cover gasket ArvinMeritor Differential Carrier Series 7 13

Exploded view Curvic version - snap ring version - Single reduction differential carrier type MS15 - MR15 55 56 57 13 8 9 snap ring spigot bearing 10 11 12 32 35 64 49 50 23 25 24 3 26 2 1 19 15 21 20 5 16 7 3 37 4 6 34 5 31 6 29 28 33 30 29 27 29 model without differential lock 60 63 59 58 61 62 38 39 41 14 18 17 31 30 28 29 40 42 43 45 48 44 46 47 52 53 54 36 19 22 51 Fig. 6

Parts list Ref Description Ref Description 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 Carrier Bearing cap L.H. Pin Bearing cap R.H. Bearing cap washer Bearing cap capscrew Identification plate Pinion bearing cage (pinion-pac) O-ring (pinion cage) Pinion cage shim Pinion cage shim Pinion cage shim Pinion cage capscrew Plane half diff case Diff bearing cup L.H. Diff bearing cone L.H. Diff bearing cup R.H. Diff bearing cone R.H. Adjusting ring Diff case screw Cotter pin Pin spirol Plug Thrust screw Wear pad Thrust screw nut Diff spider Diff pinion Diff pinion thrust washer Diff side gear Side gear thrust washer Drive pinion Drive gear 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 64 Ref. 58 59 60 61 62 63 Flange half diff case Pinion spigot bearing Drive pinion nut Drive gear screw Shift fork Shift fork pin Shift shaft Shift shaft spring Piston Piston O-ring Cylinder end cover Cylinder cover gasket Cover capscrew Cover capscrew washer Plug Sensor switch Lock nut-sensor switch Clutch collar Fixed collar Spacer Retaining ring Companion flange Deflector Pinion pac-seal Snap ring model without differential lock End cover Sensor switch hole blanking plug Washer plug End cover capscrew End cover capscrew washer End cover gasket ArvinMeritor Differential Carrier Series 7 15

16 ArvinMeritor Differential Carrier Series 7

Maintenance 2 pg. 18 Single reduction differential carrier: removal and installation 19 Repairing the single reduction differential carrier 27 Installing the one-piece spigot bearing on the drive pinion with snap ring 29 Calculating thickness of shim pack 33 Hypoid gear set - tooth contact patterns 38 Lock nut sensor switch 39 Replacing pinion-pac seal 41 Torque chart ArvinMeritor Differential Carrier Series 7 17

2 Maintenance Introduction In order to ensure reliable and efficient differential unit operation, maintenance intervals, use of lubricants and correct procedures specified by the manufacturer should be strictly observed (refer to Lubrication Maintenance Manual no. 1). For further information contact the manufacturer s engineering department or refer to the ArvinMeritor Web site at www.arvinmeritor.com (technical library manuals). Spare parts Use original Meritor spare parts only. Differential removal and installation Removal 1. If the vehicle is loaded, unload the rear axle before removing the differential. 2. Place the vehicle on level ground and chock the front wheels. 3. Rest the rear axle on two suitably strong stands (fig. 5). 4. Remove the drain plug from the rear axle bottom end and drain lubricant. 5. Engage differential lock before air pressure falls below 2.8 bars 6. Remove axle shaft mounting screws and washers. 7. Remove axle drive shafts. 8. Remove propeller shaft. Checking rear axle housing Check rear axle alignment to prevent possible distortion from causing abnormal stress, noise and pneumatic consumption. Installation Reverse the removal operation sequence and torque fastening screws and/or nuts to tabulated specifications. Clean mounting faces and threads thoroughly, then coat the rear axle mounting face with alcohol-base lining silicone sealant Dow Corning 9071 type. CAUTION: Only original Meritor spare parts should be used. Use of non-original parts could seriously affect differential unit performance. Use of non-recommended lubricants will adversely affect performance and service life. WARNING: Waste oil disposal must be carried out in conformity with the legislation in force. CAUTION: Differential carrier removal and handling should be performed using the specified lifting and carrying equipment. CAUTION: During dismantling/reassembly operations always engage differential lock to ensure alignment of the splined sections and prevent shift fork bending and spline damage. 9. Disconnect compressed air lines and differential lock sensor switch coupling. 10. Remove differential carrier to rear axle housing fastening screws (leave two screws in place to prevent the differential from falling). 11. Safely support carrier assembly with suitable lifting tool to aid removal. Remove plastic protective plugs (22) fitted to the extraction screw holes. Fit extractor screws (Service tool CT08) Remove final 2 carrier screws to withdraw carrier assembly. 18 ArvinMeritor Differential Carrier Series 7 Fig. 7 Stands Lift or rest area

2 Maintenance Finally ensure that: There are no leakages from air lines. Lubricating oil meets manufacturer s specifications. Differential lock cab warning lamp functions correctly. 2. Remove switch (1) 3. Loosen screws (2) and remove cylinder end cover (3) and gasket (7); 4. Remove piston (4), shaft (5) and spring (6). (Fig.10) Repairing the single reduction differential carrier Disassembly 1. Suitably secure the carrier unit to the work bench. (Fig. 9) 5. Curvic Version : Loosen thrust screw nut (1) using service tool CT09 and release thrust screw (2) (Fig. 11) silicone sealant Fig. 8 Fig. 9 Fig. 10 Fig. 11 ArvinMeritor Differential Carrier Series 7 19

2 Maintenance 6. Remove shift fork (3) together with clutch collar (2). 7. Standard version: remove cotter pin (1) Curvic version: remove pin spirol (4) 8. Remove cotter pin from collar s opposite side. (Fig.12) 9. Undo bearing adjusting rings (1). 10. Use a suitable wrench to loosen and remove screws (2) with their washers; repeat the same operation on the opposite side; 11. Remove bearing caps (3). (Fig. 13) Fig. 12 12. Using suitable lifting equipment (1) remove the gear case (2) with drive gear and bearing cups (3). (Fig. 14) NOTE: Differential carrier removal and handling should be performed using the specified lifting and carrying equipment. 13. With flange lock tool CT03 (2) block rotation of companion flange (1). 14. Using wrench and service tool CT 02 (3) and torque multiplier (4) loosen bevel drive pinion nut (5), but do not remove. (Fig.15) 15. Remove and discard the capscrews (3) fastening the drive pinion bearing cage to the carrier (4). Fig. 13 Fig. 14 Fig. 15 20 ArvinMeritor Differential Carrier Series 7

2 Maintenance 16. Fit eye hooks to the flange and take out the bearing cage (5) from the carrier; ensure alignment of the differential unit during the removal operation by means of two stud bolts special tool CT08. Remove and discard drive pinion nut (1) and withdraw the companion flange (2) using a puller, if necessary. (Fig. 16) 17. Remove pinion to drive gear backlash adjustment shims (6) and measure the overall shim thickness by means of a micrometer gauge. Fig. 16 Remove differential bearings 1. Use a suitable puller (1) to remove bearing (2). (Fig.17) 2. Turn the differential case assy upside down and remove bearing cone (1).(Fig.18) 3. Prevent the differential case from turning by securing it to a suitable fixture (1). 4. Undo self-locking screws and discard (2) fastening the drive gear (3) to the flange half diff case. 5. Drive off the ring gear using either a bronze drift or a press. (Fig. 19) Fig. 17 Fig. 18 Fig. 19 ArvinMeritor Differential Carrier Series 7 21

2 Maintenance 6. Mark the two case halves (2 and 3) and the spider (4) for correct mating at reassembly. 7. Remove screws and discard (1) and raise the flange half diff case. (Fig. 20) Fig. 20 * Fig. 21 match marking Disassembly the drive pinion from bearing cage (pinion-pac) * 1. If the pinion spigot bearing (1) shows traces of wear or damage and needs to be replaced, use an appropriate puller to remove it from the bevel pinion (2). (Fig. 21) * Curvic single reduction differential carrier - Snap ring version type MS15-MR15 Remove the snap ring from the end of drive pinion with snap ring pliers that expand. Remove the spigot bearing from the drive pinion with a bearing puller. CAUTION: To prevent serious eye injury caused by splinters, always wear protection goggles when performing the above removal operation. 2. With use of a press to drive the bevel pinion (1) off the bearing cage using special tool CT04 - (Fig. 22) 3. Use a suitable tool (1) to remove bearing (2). (Fig. 23) Fig. 22 Fig. 23 22 ArvinMeritor Differential Carrier Series 7

2 Maintenance Inspection of differential components 1. Clean all differential components thoroughly. 2. Lubricate the bearings and rock the roller cage: rotation should be smooth without any sign of binding. 3. Inspect the bevel drive gear mounting face and ensure complete mating contact with the case abutment. Misalignment or distortion of these faces can cause mounting screw vibrations leading to premature failure of the unit. 4. Inspect the splined section of final drive pinion for signs of excessive wear; if so, replace bevel gear pair and companion flange. Fig. 24 Differential case assembly 1. Place plain case half (3) on the work bench. 2. Arrange the side gear thrust washer (2) in the case half; then fit the side gear (1). (Fig. 24) CAUTION If the spider has not been replaced, check for correct alignment of match marks made at disassembly, to avoid excessive runout at backface of drive gear. 3. Fit the spider (6) to the case half (3) together with diff pinions (5) and thrust washers (4). 4. Install the second side gear (2) with its thrust washer (1). (Fig. 25) Fig. 25 NOTE: Lubricate all components with rear axle filling oil. 5. Install flange case half (2). Ensure match markings made at disassembly are correctly aligned. Fit new screws and tighten them according to the following sequence: ArvinMeritor Differential Carrier Series 7 23

2 Maintenance Tightening sequence to be observed in all fastener tightening operations: 1. tighten the first capscrew pair positioned at diametrically opposite ends; 2. proceed as specified at no. 1 above with the second capscrew pair (perpendicular to the first one); 3. carry out the screw tightening operation following the same pattern. Stage 1: Tighten to 100 Nm (10 kgm) torque with torque wrench (3) (Fig. 26) Fig. 26 Stage 2: Lock screws to an angle of 110 to 120 by means of box wrench (3). (Fig.27) CAUTION: Wear safe clothing and gloves for protection from injury when working with the hot bearing. 6. Heat bearing (2) in an air oven to a temperature of 100 for about 15 minutes and drive it in place using a suitable drift. (Fig. 28) 7. Heat the drive gear (1) in an air oven to a temperature of 100 C to 150 C and install it on the flange case half. Ensure it is free to rotate, then fit four screws to ensure alignment of fastener holes of drive gear and flange case half. Alternately, heat the drive gear in a tank of water to a temperature of 70 C to 80 C for about 15 minutes before reassembly according to the above procedure. Do not press a cold drive gear on the flange case half. A cold drive gear will damage the case half because of the interference fit. Fig. 27 CAUTION: Wear safe clothing and gloves for protection from injury when working with the hot drive gear Fig. 28 24 ArvinMeritor Differential Carrier Series 7

2 Maintenance 8. Wait for the drive gear to cool down and then turn the bearing cage upside down on the tool. 9. Fit screws (1) and tighten them according to the following sequence: Stage 1: Tighten to 100 Nm (10 kgm) torque with torque wrench (2); (Fig. 29) Stage 2: Lock screws to an angle of 80 to 90 by means of box wrench (1). (Fig.30) Fig. 29 10. Heat bearing (2) in an air circulation oven to a temperature of 100 C for 15 minutes and drive it in place using a suitable drift. (Fig.30) CAUTION: Wear safe clothing and gloves for protection from injury when working with the hot bearing. Assembling drive bevel pinion on bearing cage 1. Heat bearing (2) in an air circulation oven to a temperature of 100 C for 15 minutes and drive it on bevel pinion (1). Wait for the bearing to cool down. (Fig. 31) Fig. 30 CAUTION: Wear safe clothing and gloves for protection from injury when working with the hot bearing. 2. Using service tool CT11 (1) to press the bearing cage (2) onto the bevel pinion (3). (Fig.32) Fig. 31 Fig. 32 ArvinMeritor Differential Carrier Series 7 25

2 Maintenance 3. Proceed as follows if a new pinion spigot bearing needs to be installed: Heat the spigot bearing (1) in an air circulation oven to a temperature of 100 C for 15 minutes and drive it onto bevel pinion (2).(Fig.33) CAUTION: Wear safe clothing and gloves for protection from injury when working with the hot bearing. WARNING: When installing the spigot bearing, place the larger radius toward the pinion head. Fig. 33 4. Stake the bevel pinion spigot at ten evenly spaced points, as shown using special tool CT06. If dents from previous operations can still be noticed, make sure the number of full indentation is no less than the number of pinion teeth (a full indentation is a mark that does not spread out into the milling hollow). (Fig. 34) CAUTION: The indentation diameter must be between 3.40 and 4.10 mm, corresponding to a depth of 0.30 to 0.44 mm under a load of 4000 kg and a ball 10 mm in diameter. bevel pinion spigot 2,3 Fig. 34 26 ArvinMeritor Differential Carrier Series 7

2 Maintenance Alternative bearing retension Installing the one-piece spigot bearing on the drive pinion with snap ring 1. Place the drive pinion in a press, gear head (teeth) toward the top. 2. Press the spigot bearing on the end of drive pinion until the bearing is flat against the gear head. Use special tool CT05 against the bearing in race. (Fig. 35) press sleeve spigot bearing NOTE: When installing the spigot bearing, place the larger radius toward the pinion head, as shown. 3. Install the snap ring (*) into groove in end of drive pinion with snap ring pliers. (Fig. 36) Fig. 35 NOTE: (*) Some Meritor carriers do not have these described parts. Completing assembly operations snap ring spigot bearing 1. Position the drive input flange (1) complete with deflector (2) and drive it home with service tool CT11 the use of a press is recommended. (Fig. 38) 2. Temporarily tighten the retaining nut. spigot bearing snap ring Fig. 36 Fig. 38 Fig. 37 ArvinMeritor Differential Carrier Series 7 27

2 Maintenance WARNING: Where the same pinion-drive gear assembly is used as was taken off when dismantling, position the previously measured shim pack (2) and the bevel pinion bearing cage (1) with the bearing cage o-ring, on the carrier (3), making sure the oil passage groove is correctly lined up using service tool CT 08 for alignment. (Fig. 39) Replace the o-ring if damaged to avoid oil leakage through the shims. 3. If the gearset is replaced with a new ring and pinion, the correct location of the pinion is critical and is established by reference of the markings on the pinion and drive gear. Fig. 39 1. Part number. 2. Tooth combination number. 3. Pinion-drive gear pair set number. 4. Variation number needed to determine the thickness of the shim pack to be interposed between pinion bearing cage and differential carrier (in the examples below, the number is identified as P.C.). 5. Pinion-drive gear set manufacturing and testing date (month/year). 6. Pinion-drive gear set nominal backlash value. Part and tooth combination numbers are stamped at the threaded end of all pinions. On drive gears these numbers are usually stamped on the outer face. In any final drive set the drive gear will always bear an even category number (example: 36786) while the mating pinion will bear an odd category number (example: 36787). The tooth combination number (example, 10-41) indicates that the pinion has 10 teeth and the drive gear 41, equal to a drive ratio of 4.10 : 1. Fig. 40 WARNING: Never use a pinion and drive gear set unless both components have the same match number Every drive gear is marked with a variation number which indicates the nominal assembly distance. Use this number to calculate the thickness of the shim pack that is interposed between pinion bearing cage and differential carrier. This variation number (example, PC + 0.1 or PC 0.1 mm) is stamped on the drive gear outer face. 28 ArvinMeritor Differential Carrier Series 7

2 Maintenance Adjusting the pinion cage shim pack thickness 1. Measure the thickness of the shim pack removed with the old pinion-drive gear assembly. Use a micrometer or a gauge and take a note of the reading. 2. Read the P.C. marked on the drive gear to be replaced. If it is a plus (+) number, subtract it from the value obtained under item 1. above. If it is a minus (-) number, add it to the value obtained under item 1. above. WARNING The value obtained at Example 2 will be used to calculate the thickness of the shim pack to be interposed between pinion bearing cage and differential carrier for correct new final drive assembly. Spare shims to be interposed between differential carrier and bevel pinion bearing cage are available in thicknesses of 0.125 0.200 0.500 mm. Take note of the result. 3. Read the P.C. marked on the new drive gear. Either add or subtract the resulting value depending on the variation sign (+ add, - subtract) from the measurement taken at item 2. above. The resulting value indicates the thickness of the new shim pack to be assembled. Refer to the following examples which cover all the possible calculation combinations. All final drive sets are stamped with a number indicating the nominal backlash between pinion and drive gear obtained when machining was finished. This backlash value is shown on the drive gear outer diameter. Example 1: Original shim pack thickness mm 0.75 P.C. marked on old drive gear + 0.05-0.05 Resulting value mm 0.70 P.C. marked on new drive gear + 0.10 + 0.10 Thickness for new shim pack mm 0.80 Example 2: Original shim pack thickness mm 0.65 P.C. marked on old drive gear - 0,05 + 0.05 Resulting value mm 0.70 P.C. marked on new drive gear + 0,15 + 0.15 Thickness for new shim pack mm 0.85 Example 3: Original shim pack thickness mm 0.70 P.C. marked on old drive gear + 0,05-0.05 Resulting value mm 0.65 P.C. marked on new drive gear - 0,05-0.05 Thickness for new shim pack mm 0.60 Example 4: Original shim pack thickness mm 0.85 P.C. marked on old drive gear -0,10 + 0.10 Resulting value mm 0.95 P.C. marked on new drive gear - 0,15-0.15 Thickness for new shim pack mm 0.80 10 = combination number +0.05 = P.C. (Pinion Cone) 10/00 = manufacturing month/year B/L 0.32 = pinion/drive gear assembly nominal backlash value Fig. 41 ArvinMeritor Differential Carrier Series 7 29

2 Maintenance Differential carrier general assembly 1. Fit new screws (2) and tighten in two stages as follows: Stage 1: Tighten with torque wrench (1) to 100 Nm (10 kgm); (Fig. 42) Stage 2: Lock screws (2) with box wrench to an angle of 60 to 70 (1). 2. Turn the unit around by 90. 3. Block companion flange rotation (3) by means of service tool CT 03 (5). Use socket (2), torque multiplier (4) and torque wrench (1) to tighten new drive pinion nut to the specified torque (1350 to 1670 Nm). (Fig. 43) Fig. 42 Torque multiplier: Ensure the torque multiplier ratio is correct. 4. Position the caps taking care to align the locating dowels. Insert capscrews complete with washers and tighten using a torque wrench to 650 to 810 Nm. 5. Check that bearing cups (1) slide into their housings with light pressure without sticking. 6. Unscrew the retaining screws with washers again and remove the caps. Fig. 43 Fig. 44 30 ArvinMeritor Differential Carrier Series 7

2 Maintenance 7. Position bearing cups (3). 8. Use a suitable lifting device (1) to lift the previously assembled differential assembly (2) and position in carrier. (Fig. 45) WARNING: Differential carrier removal and handling should be performed using the specified lifting and carrying equipment. 9. Position the caps (2) making sure locating dowels are aligned. 10. Fit cap screws (3) with washers; use torque wrench (1) to tighten capscrews without locking to specified torque. (Fig. 46) Fig. 45 11. Lubricate taper roller bearings (1) with axle oil; screw in adjusting rings (2) manually until they touch bearing cups; lock capscrew (3 fig. 46) to 650 to 810 Nm (65 to 81 kgm). (Fig. 47) Adjusting preload of differential bearings Expansion between bearing caps (leg spread) can be performed in two methods: method 1 : 1. Use wrench service tool CT 12 (3, fig. 48) to tighten bearing adjusting rings (4) until pinion-to-drive gear end play and backlash readings are zero; also check that the drive gear is not jammed against the pinion. Fig. 46 Fig. 47 Fig. 48 ArvinMeritor Differential Carrier Series 7 31

2 Maintenance 2. With an appropriate micrometer positioned crossways at points X and Y (arrows, fig. 49), read and take a note of distance between caps. 3. Tighten adjusting rings (4, fig 48) until cap (2, fig. 48) divergence - measured on either axes X or Y, as described at point 2. above - reads between 0.15 and 0.33 mm, corresponding to a bearing preloading of 1.7 to 3.9 Nm (0.17 to 0.39 kgm). method 2 : 1. Place two magnetic-base dial gauges in central and crossways position on the outer machined faces of caps (2, fig. 48), as shown in fig. 48; Fig. 49 2. Proceed as specified at 1.1 above.; 3. When backlash and end play are zero, continue tightening both adjusting rings (4. fig. 48) until the cap divergence reading sets between 0.15 and 0.33 mm, which corresponds to the sum of readings on dial gauges (1). Hypoid ring gear backlash adjustment Proceed as follows to adjust end play between teeth of piniondrive gear assembly, which should be: 0.20-0.45 mm for MS15-MR15 0.26-0.50 mm for MS16-MS17: Fig. 50 a. stop bevel drive pinion rotation; b. position a magnetic-base dial gauge (1) as shown in fig. 50; c. use wrench service tool CT 12 (3) to slacken the adjusting ring on drive gear side and tighten the adjusting ring on the opposite side (2) by the same amount (by doing so, the previously measured cap divergence reading remains unchanged); d. proceed as previously described to obtain the specified end play value. End play should be checked at four evenly spaced points. 32 ArvinMeritor Differential Carrier Series 7

2 Maintenance Adjusting preload of differential bearings Expansion between bearing caps (leg spread) can be performed in two methods: Use a magnetic-base dial gauge (1) to measure drive gear (2) runout: it should not exceed 0.20 mm. If not, dismantle the differential unit and trace the cause for the defect. (Fig. 51) Reassemble the unit and repeat the above adjusting operations. With a brush, apply a thin coat of Prussian blue to the drive gear teeth. Rotate the pinion and examine the contact marks left by the pinion teeth on the drive gear teeth. The following figures illustrate the possible types of contact and the methods for correcting any errors. Fig. 51 Fig. 52 Tooth contact pattern of the gear set 1. Coast (concave side) 2. Toe 3. Drive (convex side) 4. Heel DRIVE SIDE Central toward the toe over the face of the gear tooth and in the centre on the tooth profile (page 35). COAST SIDE Central toward the heel over the face of the gear tooth and in the centre along the tooth profile (pag. 35). Fig. 53 ArvinMeritor Differential Carrier Series 7 33

2 Maintenance Excessive contact toward the top of the gear tooth. Conditions A-B. - (pag. 35) Indicates that pinion is located too far outward and needs further adjustment. For a more correct positioning, remove shims under its bearing cages required to ensure proper contact. Condition A - (pag. 35) Remove shims and increase backlash toward maximum value. Condition B - (pag. 35) Check backlash reading, remove shims and set to correct value. Fig. 54 Excessive contact toward bottom of drive gear tooth. Conditions C-D. - (pag. 35-36) Indicates that pinion is located too deep inward and needs further adjustment. For a more correct positioning, add shims under its bearing cage as required to ensure proper contact. Condition C - (pag. 35) Check backlash reading, add shims and set to correct value. Condition D - (pag. 36) Add shims and decrease backlash toward minimum value. Fig. 55 Condition E - (pag. 36) Condition F - (pag. 36) Decrease backlash Increase backlash WARNING Should pinion spigot bearing interfere with drive gear while the shim pack is replaced, loosen the ring nut on the drive gear rest side and take note of its position; replace shims and return the ring nut to its previously recorded position. Adjust backlash Fig. 56 34 ArvinMeritor Differential Carrier Series 7

2 Maintenance Tooth contact patterns of hypoid gear set Theoretical contacts DRIVE SIDE (drive gear convex side) TOP COAST SIDE (drive gear concave side) TOP HEEL TOE HEEL BOTTOM BOTTOM DRIVE: Central toward the toe over the face of the gear tooth and in the centre on the tooth profile. COAST: Central toward the heel over the face of the gear tooth and in the centre along the tooth profile. DRIVE SIDE TOP Condition A COAST SIDE TOP HEEL TOE HEEL BOTTOM DRIVE-RELEASE: Excessive contact toward the top DRIVE: Excessive contact toward the toe COAST: Excessive contact toward the heel REMEDY: Remove shims and increase backlash to maximum value BOTTOM TOP Condition B TOP HEEL TOE HEEL BOTTOM DRIVE-COAST: Excessive contact toward the top REMEDY: Take backlash reading, remove shims, set backlash to correct value TOP Condition C BOTTOM TOP HEEL TOE HEEL BOTTOM DRIVE-COAST: Excessive contact toward the bottom. REMEDY: Take backlash reading, add shims, set backlash to correct value BOTTOM

2 Maintenance DRIVE SIDE TOP Condition D COAST SIDE TOP HEEL TOE HEEL BOTTOM BOTTOM DRIVE-COAST: Excessive contact toward bottom. DRIVE: Excessive contact toward heel. COAST: Excessive contact toward toe. REMEDY: Add shims and decrease backlash to minimum value. TOP Condition E TOP HEEL TOE HEEL BOTTOM BOTTOM DRIVE: Excessive contact toward heel. COAST: Excessive contact toward toe. REMEDY: Decrease backlash. TOP Condition F TOP HEEL TOE HEEL BOTTOM BOTTOM DRIVE: Excessive contact toward toe. COAST: Excessive contact toward heel. REMEDY: Increase backlash. 36 ArvinMeritor Differential Carrier Series 7

2 Maintenance 7. Standard version: Fit cotter pin (1) and bend it over. Repeat the same operation on the opposite side. Curvic version: Fit cotter pin (1) to collar s opposite side and bend it over. 8. Curvic version: Fit pin spirol (2) to collar s opposite side. 9. Install shift fork (2) with collar (1). 10. Coat with Molikote Gn Plus grease the shift fork s slanting face. 11. Position the shift fork and the collar together with spring using service tool CT07 (3) and shift shaft (4). 12. Fit the piston (5) with its 0-ring. Before assembling the piston coat the 0-ring seal with Molikote 44 Medium grease. 13. Fit the cylinder end cover (6) with gasket (8), insert screws with washers and tighten with a torque wrench to 12 to 16 Nm. Fig. 57 Standard version Curvic Version: 14. Fit the thrust screw (1) and nut (2); tighten screw to abutment against the drive gear face until resistance is felt. Apply Loctite 573 on the thread. 15. Undo thrust screw by 180 approximately (clearance should be between 0.65 and 1.14 mm). 16. Tighten nut to a torque of 270 to 335 Nm. (Fig. 60) Fig. 58 Curvic version Fig. 59 Fig. 60 ArvinMeritor Differential Carrier Series 7 37

2 Maintenance Instructions to install and adjust differential lock sensor switch Fig. 61 WARNING Check and adjustment of differential sensor switch is carried out with rear axle installed on vehicle. 1. Before screwing in the switch, coat switch point with Molikote Gn Plus grease, screw the switch threads and apply sealant Loctite 573 on the threads. 2. Engage differential lock and tighten sensor switch until the switch point touches the shift fork slightly; check that warning lamp illuminates on dashboard. 3. As soon as the warning lamp is switched on in cab, turn the switch one additional revolution. 4. Tighten the lock nut from 35 to 45 Nm. 5. Check differential lock engagement by blowing in air (6 kg/cm2/6 bar approximately). 6. Release differential lock and ensure in this condition warning lamp in cab is off. 7. Repeat the above operations several times before running the vehicle on the road. 38 ArvinMeritor Differential Carrier Series 7

2 Maintenance Replacing pinion-pac seal The following repair operation may be carried out with differential unit installed on vehicle. Disassembly 1. Unscrew nuts (1) fastening propeller shaft to differential companion flange. 2. Disconnect the propeller shaft (2) and secure it to the chassis. Fig. 62 Fig. 62 3. Block the rotation of flange (1) by means of service tool CT03 (2). 4. With wrench (3), torque multiplier (4) and service tool CT02 slacken bevel pinion nut and withdraw flange (1) Fig. 63. 5. With a suitable tool raise the outer edge of metal inner ring (1) in two opposite points. Fig. 64 6. Pry with two levers (2) to withdraw inner ring (1). Fig. 65 7. Pry with the lever in the direction shown by the arrow to remove grommet (1). Fig. 66 Fig. 63 Fig. 65 Fig. 64 ArvinMeritor Differential Carrier Series 7 39

2 Maintenance Assembly 1. Accurately clean the seal ring seat from any trace of dirt or oil. 2. Position a new seal ring (1). Fit service tool CT01 (2), screw in a guide nut machined out of the old drive pinion nut, and bed the seal ring to stop.(fig. 67) 3. Loosen the guide nut, remove installer (2), reassemble the flange and screw in a new nut; lock to the specified torque using torque wrench and multiplier. Reassemble the propeller shaft and tighten fastening nuts to the specified torque. Fig. 66 Fig. 67 40 ArvinMeritor Differential Carrier Series 7

Torque chart 5 4 8 3 6 2 1 7 Fig. 68 Description Torque Nm Kgm 1 Stud nuts and/or capscrews carrier to housing stage 1 torque 100 10 (M16x2 Durlock) stage 2 angle 80-90 2 Diff. case screws stage 1 torque 100 10 stage 2 angle 110-120 3 Drive gear screws stage 1 torque 100 10 stage 2 angle 80-90 4 Drive pinion nut 1350-1670 135-167 5 Pinion cage capscrews stage 1 torque 100 10 stage 2 angle 60-70 6 Lock nut sensor switch 35-45 3.5-4.5 7 Cover capscrews 10-12 1.0-1.2 8 Thrust screw nut 270-335 27-33.5 Bearing cap capscrews (not showed) 650-810 65-81 ArvinMeritor Differential Carrier Series 7 41

42 ArvinMeritor Differential Carrier Series 7

Troubleshooting 3 pg. 44 Troubleshooting ArvinMeritor Differential Carrier Series 7 43

3 Troubleshooting The following chart shows the most common faults occurring to a differential unit. Fault 1. Wheel hub noise and possible overheating Possible causes The oil used is not of the type specified by the manufacturer Low oil level Incorrect backlash between drive gear teeth Gears damaged Bearings worn or maladjusted Incorrect use of retarder/exhaust brake Remedy Drain oil from housing and fill with new oil of the specified type Top up oil level in housing Remove bevel drive gear pair. Trace cause for possible gear damage. Adjust as required Replace defective components Replace defective components Check retarder/exhaust brake efficiency and setting. Look for possible damage to bevel drive gear pair and bearings 2. Anomalous knocks from the differential during acceleration / deceleration stages Diff pinion thrust washers worn Diff pinion or diff spider worn Driving wheel loose on hub Differential unit splined sections worn Replace all thrust washers Replace worn components Check wheel nuts at regular intervals and tighten, as required Replace worn components 3. Noise when travelling Low oil level in axle housing Teeth and/or bearings worn or damaged Bearings maladjusted or damaged Top up oil level Replace damaged components Adjust bearings and replace, as required 4. Oil leakages Excessively high oil level in axle housing Breather blocked Seal rings damaged Screws/nuts loose Seal between axle housing and differential unit damaged Check oil level Clear/replace breather Replace damaged seal rings Clean threads, coat with sealant if necessary, and tighten to the specified torque Remove differential unit, check and clean all sealing surfaces and coat parts concerned with sealant, as required 44 ArvinMeritor Differential Carrier Series 7

Meritor Heavy Vehicle Braking Systems Grange Road, Cwmbran Published in Italy South Wales NP44 3XU - U.K. Tel.: +44 (0) 1633 834238 Copyright 2002 Issued 4/2003 Fax: +44 (0) 1633 834191 www.arvinmeritor.com ArvinMeritor Inc. M-graph - MM0140