To Dismantle
Observe the following before dismantling the gearbox:
^ remove the reversing-light switch to prevent it being damaged and cover the hole left by the switch.
^ clean the gearbox.
After cleaning the outside of the gearbox, start work as follows:
IMPORTANT: The openings for the drive shafts and the delivery line to the slave cylinder must be covered before cleaning the gearbox. Plug for drive shaft, part no. 87 92 665.
1. Secure the gearbox in a work fixture with holder 87 92 228.
2. Detach the delivery line. Compress the sleeve on the inside using pliers and push the delivery line forward. Pry up the catch on the sleeve and press in the delivery pipe to detach it.
3. Undo the slave cylinder screws and remove it.
4. Unscrew the reverse shaft. Note the O-ring.
5. Unscrew the end cover. Remove the cover and the gasket.
6. Engage 1st gear to secure the gearbox and prevent the selector mechanism detent balls from coming out. Tap out the retention pin for the 5th gear selector fork.
IMPORTANT: Before removing the synchromesh sleeve, mark its position relative to the 5th gear synchromesh with a pen to facilitate refitting.
Remove the fork and synchromesh sleeve and then refit the synchromesh sleeve.
7. Press down the synchromesh sleeve so that 5th gear is engaged. Two gears must be engaged simultaneously when the nut on the output shaft is unscrewed.
Note that the synchromesh sleeve may only be placed on the synchromesh hub when the high lugs on the sleeve are opposite the tooth gaps on the synchromesh hub that are opposite the deep tooth gaps.
8. Tap off the lock on the output shaft nut using a drift. Remove the nut.
IMPORTANT: In all work which involves dismantling the gearbox, a new nut and a new clamping sleeve should be fitted on assembly as the old clamping sleeve will have lost its tension.
9. Remove the circlip for 5th gear synchromesh hub. This is made easier by first carefully tapping down the hub.
Lift off the sleeve and then use puller 87 91 287, arm 87 91 303 and removal tooled 92 640 to lift off the 5th gear synchromesh hub (grease the tip of the puller). Collect the leaf springs. Then lift up the pinion, balk ring and needle bearing.
10. Remove 5th gear with puller 89 96 084, puller 87 92 566 and sleeve 87 91 410.
11. Undo the screws for the differential seal retainer.
12. Remove the seal retainer and keep the shims.
13. Undo the screw for the reverse shaft support in the gearcase.
14. Undo and remove the bolts from the mating surface between the gearcase and the clutch housing. Tap down the 2 locating sleeves.
15. Check that the gear is engaged. This prevents input and output shafts from coming out. Screw on two attachment eyes 87 92 129. Sleeve 87 91 410 is fitted on the output stub axle. Hook puller 87 91 287 with arm 87 91 303 in the tools and carefully pull off the housing until the gear and bearing release from the shaft. Tap carefully so that the mating face releases.
16. Remove tools. Lift off the gearcase.
17. Tap out the differential bearing race. Use sleeve 87 92 202.
18. Remove shaft and selector fork for reverse.
19. Unscrew and remove the reverse gear selector fork.
20. Engage reverse gear on the selector mechanism to gain access to the screw for the selector rod.
21. Remove the screw for the driver on the selector rod. Withdraw the shaft and keep the driver.
22. Disengage reverse. Remove the screw and lift the selector mechanism slightly to lift the locating sleeves from their seats. Lift off the sleeves.
Pull the selector mechanism back towards the differential and angle it out slightly. Lift out the selector mechanism.
23. Lift the input shaft slightly and lift the reverse shaft and pinion (reverse gear).
24. Lift off the 4th gear wheel, clamping sleeve and spacer sleeve.
25. Fit puller 87 91 287 with arm 87 91 295 under the 1st gear wheel on the output shaft. Lift up the drive assembly with two screwdrivers so that the shanks go in under the 1st gear drive. Fit sleeve 87 91 410 as protection on the output shaft. Pull slightly and fit assembly fixture 87 92 103 that hold together the 1st and 2nd gear synchromesh assembly. Fit a retaining strap around the tools and drive assembly. Pull up all gear wheels approx. 15 mm on the output shaft.
26. Lift out the input shaft.
27. Tighten until the gear wheels on the output shaft become detached.
28. Lift off the gear wheels (1st, 2nd and 3rd gears), balk rings and sleeve, which are held together by assembly fixture 87 92 103.
29. Undo 4 bolts and remove the output shaft bearing support.
NOTE: Assist the removal of the bolts by heating the gearcase so that the thread locker breaks. Tapping with a centre punch will also assist in removing the bolts.
30. Pull up the output shaft. Use support 87 91 188, driver 87 91 428 and puller 87 91 261.
31. Lift out the differential.