Procedures
General Repair Information
Carefulness, cleanliness and the correct tools are required for transmission repairs to be successful. The usual basic safety precautions apply when making vehicle repairs.
Some of the general information that is included with other procedures in this service information are summarized here.
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 bolt allocation, refer to the Parts Catalog.
• Fill the transmission fluid when repairing the manual transmission.
Gaskets, O-rings and Seals
• Thoroughly clean the separation surfaces and apply sealing paste (AMV 188 200 03).
• Apply the sealing paste evenly and not too thick.
• Fill the space between the sealing and dust lips halfway with sealing grease for seal (G 052 128 A1) - arrow - before installing the seal.
• The open side of the seal point toward the fluid to be sealed in.
• After installing, check the transmission fluid level. Refer to => [ Transmission Fluid, Checking, Draining and Filling ] Service and Repair.
• Lightly lubricate O-rings before installing them, in order to prevent them from being crushed when installing.
Sealant
• Always thoroughly clean the separating surfaces on the housings before applying the sealant.
• Apply the sealing paste (AMV 188 200 03) evenly and not too thick.
• Do not allow any sealing paste to get into the ventilation holes.
Fasteners
• Replace the circlips.
• Do not overstretch the circlips.
• The circlips must fit completely inside the groove.
• Replace the roll pins. Installed position: The slit is longitudinal to the direction of force.
Bolts and Nuts
• Always loosen or tighten bolts and nuts for covers and housings in a diagonal sequence.
• Especially delicate parts, such as the clutch pressure plate, must not be distorted. Loosen and tighten the bolts/nuts in stages and in a diagonal sequence.
• The tightening specifications stated applies 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
• Install new tapered roller bearings. It is not necessary to lubricate them.
• Install needle bearings with the lettered side (thicker metal) facing the installation tool.
• Replace all the tapered roller bearings that are on the same shaft. Use tapered roller bearings from the same manufacturer.
• To install, heat the bearing inner races to approximately 100 °C (212 °F) using the inductive heat unit (VAS 6414).
• Do not interchange the inner and outer bearing races with those from other bearings of the same size, bearings are paired.
Adjusting Shims
• Measure the adjusting shims at several locations with a micrometer caliper. 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 them to the same gear.
• Check for wear and replace if necessary.
• Check the grooves - arrow 1 - on the synchronizer ring - A - and the inner race for flat areas (grooves are worn).
• The coating on the synchronizer rings must not be damaged.
• If an intermediate ring - B - is installed, check the intermediate ring on the outer contact surface - arrow 2 - and inner contact surface - arrow 3 - for grooves, scoring and blue coloring (from overheating).
• Check the taper on the drive gear for grooved and scoring.
• Coat the synchronizer ring with transmission fluid and then install.
Gears
• Before pressing them on, clean and heat the gear to 100 °C (212 °F) Max. using the inductive heat unit (VAS 6414).
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 the bolts 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.