Procedure
1. Take out the battery and remove the battery tray.
2. Take out the dipstick.
3. Thoroughly clean the valve body cover, undo the four screws and remove the cover.
4. Remove the gasket from the valve body cover.
5. Remove the boost pressure pipe.
6. Undo the ten large-headed bolts (TORX TX 27)
Important
It is very important that the bolts are refitted in the correct locations, as they are different lengths, see illustration.
7. Lift of the valve body and lay it on a clean workbench.
8. Remove the 11 bolts, see illustration,
Important
The screws are of different lengths.
Lay the upper valve body to one side.
9. Loosen the last bolt in the upper cover half a turn and rotate the upper section of the valve body approx. 5 mm so that the last screw in the lower cover is accessible.
Important
Never lift up the upper section of the valve body. If the washers in the valve body are displaced, the valve body will be unserviceable.
10. Remove the bolt from the lower cover and remove the cover.
11. Return the upper section of the valve body to its original position and secure it with a bolt through the upper cover.
12. Remove all the bolts in the side cover except for the middle one, see illustration. Hold on to the side cover and then remove this bolt as well. Make sure the springs do not fall out.
13. Remove the old springs from shift valves 2-3 and 3-4 and replace them with new ones, see illustration.
14. Refit the cover with a new gasket (44 77 386) and secure it with one bolt.
Important
Make sure the springs are not jammed.
Tighten all the bolts.
Tightening torque: 6 Nm (4.4 lbf ft)
15. Put the lower cover in place and secure it with three bolts without tightening them.
16. Undo the bolt in the upper cover and rotate the upper section of the valve body approx. 5 mm so that the last bolt in the lower cover can be screwed in.
Important
Never lift up the upper section of the valve body. If the washers in the valve body are displaced, the valve body will be unserviceable.
17. Undo the cover on the upper valve body (6 bolts) carefully as there are a number of springs under it.
18. Take out the spring to shift valve 1-2 and replace it with a new one.
19. Refit the cover.
Tightening torque: 6 Nm (4.4 lbf ft)
20. Put the upper valve body in place and secure it with the bolts without tightening them. Also screw in the bolts for the upper cover without tightening them.
Important
The bolts are of different lengths, see illustration (dimensions in millimeters).
21. Tighten all the bolts.
Tightening torque: 6 Nm (4.4 lbf ft)
Important
If a higher tightening torque is used, the pistons and valves may stick.
22. Put the gear selector mechanism in position 1.
23. Push in the control valve completely. This corresponds to position 1.
24. Carefully fit the valve body and tighten the bolts.
Important
The bolts are of different lengths. Refit them in the correct positions.
Tightening torque 10 Nm (7.4 lbf ft)
25. Change 0-rings on the boost pressure pipe and refit it. Use fixture 87 91 782.
Important
If the pipe has been deformed and does not fit the hole pattern exactly, it must be discarded as there is a risk of the sharp edges on the pipe cutting off metal chips from the holes. These chips will make the valve body unserviceable:
26. Place the gasket onto the valve body cover and fit the cover.
Tightening torque: 6 Nm (4.4 lbf ft)
27. Refit the dipstick.
28. Fit the battery tray and replace and reconnect the battery.
29. Raise the car and remove the left front wheel and the front half of the wing liner.
30. Remove the gearbox end cover (13 bolts TORX TX 27) and take off the gasket.
31. Pry up the flange and undo the 36 mm screw on the pinion shaft. Clean off any chippings on the gear wheel.
Important
The parking detent must be engaged.
32. Pull off the gear from the pinion shaft.
33. Heat with a hot-air gun and remove the bearing race to access the governor.
34. Remove governor stages 1 and 2 (black screws) as well as the spring washer securing the piston for stage 2.
Make sure all moving parts are running freely. Scratches that make moving parts stick must be rectified or the scratched part replaced. Alternatively, the entire governor can be changed.
35. Change the spring for stage 2.
36. Replace stages 2 and 1 (the parts fit in one way only).
Tightening torque 10 Nm (7.4 lbf ft)
37. Heat the gearcase with a suitable hot-air gun for 3-5 minutes at approx. 70°C (158°F) and fit the bearing race.
38. Fit the spacer sleeve and washer to the pinion shaft and fit the gear.
39. Engage the parking detent and tighten the bolt. The bolt is available in a short and a long version. Tightening torque 150 Nm (110 lbf ft) (24 mm bolt) 170 Nm (124.7 lbf ft) (70 mm bolt)
40. Apply a thin coat of acid-free vaseline to the gasket and fit it.
41. Fit the intermediate gear cover TORX TX 27).
Tightening torque 10 Nm (7.4 lbf ft)
42. Fit the wing liner and replace the wheel.
Tightening torque 120 Nm (89 lbf ft).
Lower the car.
43. Stamp the code on the gearbox plate as shown in the illustration.
B234E/B234L: 219