Primary Chaincase

The primary chaincase is removed in conjunction with the removal of the gearbox. When removed from the gearbox, the primary chaincase contains the following parts: A. Ball bearing, B. Needle bearing, C. Clutch shaft seal, D. Level control ball valve and tubular dowel. Remove these parts as follows:

BALL BEARING





To Remove
1. Remove the four Torx screws and remove the ball bearing retainer.





2. Use drift 83 90 106 and sleeve 83 90 148 to press out the ball bearing.





To Fit
1. Use tool 83 90 114 to press the bearing into the primary chaincase.





2. Fit the bearing retainer. Apply Loctite to the bolts and tighten them to a torque of 9.5 - 14 Nm (6.3 - 10.0 lb ft).

NEEDLE BEARING





To Remove And Refit
1. Use tool 83 91 997 and a drift to remove the bearing.





2. Use tool 83 91 997 and drift 78 41 067 in a press to press in the bearing.

BALL VALVE
The level control ball valve should not be removed. Only check that the ball moves freely and seals against the seat.
The function of the ball valve is to prevent the oil from running from the gearcase into the primary chaincase when the car is travelling down a long gradient. This is designed to safeguard the lubrication of the differential unit and final drive.

CLUTCH SHAFT SEAL





To Remove And Refit
1. Use a screwdriver to remove the clutch shaft seal.





2. Use drift 83 91 997 to fit the clutch shaft seal. Grease the seal lip after fitting. For particulars of the grease, seethe specification.

TUBULAR DOWEL





To remove the tubular dowel from the primary chaincase, grip it in a vice and turn the chaincase back and forth. Fit the dowel by hammering it in.