Description Of the. Disassembly, Overhaul and Assembly Of a. Distributor Nr Of a. Porsche 993 Carrera

Transcription

1 Description Of the Disassembly, Overhaul and Assembly Of a Distributor Nr Of a Porsche 993 Carrera

2 1. Introduction This article is a description of the dual distributor overhaul of Porsche 993 Carrera 4, year The description is a DIY guideline for other Porsche owners. I cannot be held responsible for any shortcomings or errors in this article For improvements me info@hd-electronics.nl Boekelo, The Netherlands December 2012, Hans Daman 2. Why and what overhauling Simply as a preventive measure! The car has run km and no evidence of previous overhauls is present. Parts to be renewed: - the 3 Angular Contact Bearings - the Distributor Belt - the O-ring 2.1. Not overhauled parts Not described in this article is the replacement of the distributor cap and the rotors. If the contacts are badly burned or the caps are cracked consider replacement. It is a good time to replace them now since you already have them off. The needle- ball bearing combination on the bottom of the primary shaft are cleaned, inspected and greased. 3. Required tooling A standard toolset (metric) will do. A vice A clamp 2

3 4. Parts 4.1. Bearings The replaced bearings are angular contact ball bearings type 7201-B-2RS-TVP with dimensions d=12mm, D=32 mm and height of 10mm. As the diameter from the primary as well as the secondary shaft is mm the inner diameter of the bearing has to be grinded from 12 to mm. For ordering the modified bearings please contact: 4.2. Distributor Belt Porsche part number O-Ring Porsche part number: Primary shaft locking pin Porsche part number:

4 5. Disassembly 1) Unplug valve connector 2) Unplug sensor connector 3) Remove 2 bolts 4) Remove intake trumpet 5) Unplug blower connector 6) Slide-of rubber sleeve 4

5 7) Slide-of rubber sleeve 8) Undo air hose 9) Protect air hose against dirt 10) Remove rear blower bolt 11) Remove front blower bolt (captive) 12) Remove blower 5

6 13) Loosen hose clamp bolt 14) Remove air hose and series resistor 15) Unscrew distributor screws (captive) 16) Unplug ignition coil connector 17) Take of distributor cap 18) Protect both distributor caps 6

7 19) To align pulley and crankcase mark, engage 5 th or 6 th gear and move car. 20) Both rotors are pointing to the respective marks on the distributor house. 21) Remove rotors and dust covers 22) Unplug Hall sensor connector 23) Unscrew M8 lock nut 7

8 24) Take out distributor 25) Locking pin has to be drilled out 26) Center mark applied 27) Start with approx. 2 mm drill 28) Gear and 4 washers (1 damaged one) 8

9 6. Distributor Belt-only replacement In this paragraph a method for replacement of the distributor belt only, without disassembly of the secondary shaft, will be described. For extended overhaul skip this paragraph and continue with paragraph 7 First execute steps 1) up to step 28) Do not remove the hall sensor components The majority of the pictures show the Hall sensor cover removed Remove 3 Phillips screws Remove connector retaining clip. Remove outer connector casing 9

10 The primary shaft including the Hall sensor can be pulled out now. See steps 39) up to 42) Remove 5 hex bolts. 2 in primary, 2 in secondary and 1 in center section Hammer back locking pins Separate upper and lower distributor housing Rotate upper and lower housing There is enough clearance now to remove and place the belt without twisting or bending it beyond the limits Place the new belt and execute step 75) up to 83) and 87) up to 88) 10

11 7. Continue with disassembly 29) Remove clip 30) Take care of small cover locking pin 31) Remove cover. I had to apply some force 32) Locking pin 33) Remove connector retaining clip 11

12 34) Remove the 3 Phillips screws 35) Remove clip 36) Remove outer connector casing 37) Remove plastic cover 38) Take out Hall sensor 12

13 39) Pull out primary shaft 40) Note position of washers 41) Note position of toothed wheel 42) Primary shaft removed 43) File down the 3 spots securing the cover and remove cover (use knife blade or so) 13

14 44) Remove retaining clip 45) Pull out secondary shaft 46) Note position of washers 47) Note position of washers 14

15 Old bearing 48) Heat the lower part (approx. 100 O C) and hammer out the 3 angular contact bearings 15

16 8. Cleaning and greasing of primary and secondary shaft In this paragraph the disassembly, cleaning, greasing and assembly of the primary shaft will be described. The activities for the secondary shaft are similar to those on the primary and are therefore not described 49) Remove woodruff key (if easy to do) 50) Slide-of washer 51) Remove springs 52) Remove retaining clips 53) Remove distributor weights 54) Remove 55) Remove Phillips screw 56) Note position 57) Remove shaft 58) Note washer 16

17 Clean and grease all parts and rebuild in reverse order Picture shows primary shaft parts 17

18 59) Partly rebuild and greased primary shaft 60) Secondary shaft. Note position 61) Secondary shaft greased and rebuild. Activities are similar to primary shaft activities 18

19 62) Distributor parts ready for rebuild 19

20 9. Distributor rebuild The replaced bearings are angular contact ball bearings type 7201-B-2RS-TVP with dimensions d=12mm, D=32 mm and height of 10mm. As the diameter from the primary as well as the secondary shaft is mm the inner diameter of the bearing has to be grinded to mm. For ordering the modified bearings please contact: Place the bearings in such a way that they are able to withstand the axial load induced by the spring washers. Push (in axial direction) on the inner ring to find out from what side the bearing can withstand axial load. The axial load direction in the distributor is from the viewpoint towards the housing as in pictures 65) and 66) 63) Heat up lower distributor housing to 100 O C. 64) Place bearing with help of socket 23 65) Bearings placed 66) Bearings placed 20

21 67) Place new belt 68) Place lower housing 69) Insert center hex bolt 70) Place secondary shaft 71) Place washers 72) Place retaining clip on the shaft above the groove 73) Place distributor in vice with socket 13 and apply moderate force to compress the spring washer until the clip snaps in to the groove 21

22 74) Retaining clip properly placed in groove 75) Place hex bolts and tighten all bolts with 8 Nm. 76) Align secondary shaft, place t two washers see 47) and then the primary toothed wheel as shown 77) Place aligned primary shaft with woodruff key! 22

23 78) Check for alignment and smooth running 79) Place rings on primary shaft 80) Place new pin ( e.g. a 4.1 mm drill bit) 23

24 81) Place gear, use a clamp to compress the spring washer, and insert pin 82) Gear and pin placed 83) Pin mushroomed to secure it in place 84) Replace Hall sensor 85) Place 3 Phillips screws and plastic cover 86) Place retaining clip 24

25 87) Place connector housing 88) Place connector retaining clip 89) Place cover and pin 90) Place retaining clip 91) Place cover. I made a new one 92) Place a new O-ring, the dust covers and rotors 93) Place distributor back in engine bay and check alignment as in 19) and 20) 94) Place M8 locknut with 20 Nm torque 95) Place distributor caps, connectors, blower and air parts in reverse order Check once again and start engine. 25