General Repair Instructions

General repair instructions
The maximum possible care and cleanliness and proper tools are essential to ensure satisfactory and successful repairs of the transmission and rear final drive. The usual basic safety precautions also naturally apply when carrying out vehicle repairs.
A number of generally valid instructions applicable for the various repair procedures which were previously repeated a number of times at numerous places in this Repair information are summarized here.

Transmission/rear final drive
^ When replacing the rear final drive, check the gear oil level and the oil for the Haldex coupling and top up as necessary.
^ When replacing the bevel box, fill up with gear oil.

^ Clean contact surfaces when installing bearing brackets and other waxed components. Contact surfaces must be free of wax and grease.

O - rings, seals, gaskets
^ Always replace O - rings, seals and gaskets.
^ Thoroughly clean joint surfaces.
Before installing:





^ Before installing radial shaft oil seals, lightly oil outer circumference and fill space between sealing lips (arrow) with a small amount of grease G 052 128 A1.
^ The open side of the oil seals faces toward the side with fluid filling.
After installation:
^ Checking oil level in rear final drive.
^ Checking oil level in Haldex coupling.





Locking devices
^ Do not overstretch circlips.
^ Always replace circlips which have been damaged or over - tensioned.
^ Circlips must locate properly in the groove.
^ Replace roll pins (position: slit - A - should be in line with the line of force - arrow -).

Bolts and nuts
^ Tighten and loosen bolts and nuts for securing covers and housings in a diagonal sequence.
^ Especially delicate parts must not be distorted. Loosen and tighten in stages in a diagonal sequence.
^ Tightening torques as specified are for unbolted bolts and nuts.
^ Replace self - locking bolts and nuts.
^ Rewax all visible surfaces of nuts/bolts and screws of all screwed connections after installing, if necessary.

Bearings
^ Install new tapered roller bearings as delivered, do not oil additionally.
^ Lubricate all transmission bearings (except tapered roller bearings) with gear oil before installing.
^ Install needle bearings with lettered side (thicker metal) toward installation tool.
^ Tapered roller bearings fitted to one shaft must be replaced as a set. Use same manufacturer of bearings.
^ Heat inner races to approximately 100° C before installing.
^ Do not interchange outer or inner races of bearings of the same size. The bearings are matched in pairs.

Shims
^ Measure shims at several points with a micrometer. Tolerance variations make it possible to find the exact shim thickness required.
^ Check for burrs and damage.
^ Only install perfect shims.

Braking tests, performance tests and towing, notes
Refer to appropriate Information.