General Repair Information

General Repair Information

Carefulness, cleanliness and the correct tools are required for transmission repairs to be successful. The usual basic safety precautions also, naturally apply when carrying out vehicle repairs.

A number of generally applicable instructions for individual repair operations, which are otherwise mentioned at various points in this repair information, are summarized here.

Contact Corrosion

• The transmission housing and clutch housing consist of a magnesium alloy.

• Bolts and other components which come into direct contact with the transmission have a surface coating adapted for this.

• Contact corrosion occurs when incorrect components (bolts, nuts, washers, etc.) are used. The transmission housing and clutch housing are damaged.

• Only install components provided in the Parts Catalog.

Special Tools and Equipment

For a list of special tools used in each repair group, refer to "Special Tools" at the end of each repair group.

Transmission

• Make sure that the alignment sleeves between the engine and transmission are positioned correctly when installing the transmission.

• Clean the contact surfaces when installing the brackets as well as any waxed components. Contact surfaces must be free of grease and wax.

• For the correct bolts and other components, refer to the Parts Catalog.

• Check the transmission fluid level. Refer to => [ Transmission Fluid Level, Checking ] Service and Repair.

• For the correct transmission fluid refer to the Parts Catalog.

Seals, Gaskets and O-rings

Replace gaskets and seals.

After removing gaskets, examine the contact surface on the housing/shaft for burrs resulting from removal or for other signs of damage.

Before installing the radial shaft seals, lightly oil the outer circumference and fill the space between the sealing lips halfway with sealing grease for seal (G 052 128 A1) - arrow -.






The open side of the seal points toward the fluid to be sealed in.

Check the transmission fluid level. Refer to => [ Transmission Fluid Level, Checking ] Service and Repair.

Lightly lubricate O-rings before installing to prevent them from being crushed when inserting.

Sealant

• Always thoroughly clean the separating surfaces on the housing before applying the sealant.

• Apply sealing paste (AMV 188 200 03) evenly and not too thick.

Fasteners

• Do not overstretch the circlips.






• Installed position for some of the circlips: The ring is narrower on top and this shape matches its installed location. This makes it easier for the pliers to grab the circlip when removing and installing it.

• Always replace damaged or stretched circlip.

• The circlip must fit completely inside the groove.

• Replace the roll pin. Installed position: The slit - A - should be in line with the line of force - arrow -.






Bolts and Nuts

• Always loosen or tighten bolts and nuts for covers and housings diagonally.

• Especially delicate parts, such as a clutch pressure plate, must not be distorted. Loosen and tighten the bolts and nuts in stages and in a diagonal sequence.

• The tightening specification stated apply to non-lubricated nuts and bolts.

• Always replace self-locking nuts and bolts.

• Make sure the contact surfaces and visible surfaces on the nuts and bolts are waxed after assembling.

• Use a thread tap to clean all threaded holes containing self-locking bolts to remove any locking fluid residue. Otherwise the bolts could shear the next time they are removed.

• Please make sure that the thread pitch is correct so that the proper thread tap is used during cleaning, and the threads do not get damaged.

Bearings

• Insert the bearings using transmission fluid.

• Heat the tapered roller bearing inner races to approximately 100 °C (212 °F) using the inductive heat unit (VAS 6414) , or equivalent before installing. Press on to the stop when installing, so there is no axial clearance.

• Do not interchange inner and outer bearing races with those from other bearing of the same size. The bearings are paired.

• Replace all the tapered roller bearings that are on the same shaft. Use tapered roller bearings from the same manufacturer.

• Set the needle bearings, ball sleeves and roller sleeves with the inscribed side (greater thickness) facing toward the drift.

Adjusting Shims






• Measure the shims at several locations with a micrometer. Tolerance variations make it possible to find the exact shim thickness required.

• Check for burrs and damage.

• Only install perfect shims.

Synchronizer Rings

• Do not interchange them. When reusing synchronizer rings, always install to the same gear.

• Check for wear and replace if necessary.

• Install them coated with transmission fluid.

Synchronizer rings for 1st through 3rd gears.






• Check the friction surface - arrow 1 - of the synchronizer ring - A - and the friction surface - arrow 3 - of the inner race - C - for grooves and scoring.

• Check the friction surface - arrows 2 - for the outer race - B - for damages (flat areas, disintegrating friction lining).

Toothed gears, synchronizer hubs

• Heat the synchronizer hub to approximately 100 °C (212 °F) with the inductive heat unit (VAS 6414) , or equivalent before installing. Press on as far as the stop when installing so there is no axial play.

• Heat the toothed gears to approximately 100 °C (212 °F) with the inductive heat unit (VAS 6414) , or equivalent before installing. Press on as far as the stop when installing so there is no axial play.

• Pay attention to the installed location.

Selector Gears

• After assembling, check the selector gears for minimum axial clearance and ease of movement.

Clutch

• Do not tilt the clutch pressure plate. Loosen and tighten it diagonally and in small steps.

• To reduce odor caused by a burnt clutch, thoroughly clean the clutch housing and the flywheel running surface with a clean cloth.