Procedures
General Repair Information
The maximum possible care and cleanliness and proper tools are essential to ensure satisfactory and successful transmission repairs. The usual basic safety precautions also, naturally apply when carrying out vehicle repairs.
A number of generally applicable instructions for individual repair procedures, which are otherwise mentioned at various points in this repair information, are summarized here. They apply to this repair information.
Components
Transmission
• Make sure that the alignment bushings 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 parts, refer to the Parts Catalog.
• Check the transmission fluid level. Refer to => [ Transmission Fluid, Checking ] Service and Repair.
• For the correct capacities, refer to => [ Codes Letters, Transmission Allocation and Capacities ] Codes Letters, Transmission Allocation and Capacities.
O-rings, Gaskets, Seals and Sealant
• Clean the housing separating surfaces thoroughly before applying the sealing paste (AMV 188 200 03).
• Apply the sealing paste (AMV 188 200 03) evenly and not too thick.
• Replace the O-rings, seals and gaskets.
• Once a seal or gasket has been removed, check the contact surface on the housing or shaft for burrs and damage caused by the removal. Repair as necessary.
• Before installing the radial shaft seals, lightly lubricate the outer circumference and fill the space between the sealing lips - arrow - halfway with sealing grease for seal (G 052 128 A1).
• The open side of the seals point toward the fluid to be sealed in.
• When installing the new shaft seals, make sure the sealing lips do not run on the same point as the sealing lip of the old seal (use insertion depth tolerances).
• Lightly lubricate O-rings before installing them to prevent them from being crushed when inserting.
• After replacing the seals and sealing rings, check the transmission fluid level and fill if necessary. Refer to => [ Transmission Fluid, Checking ] Service and Repair.
Retainers
• Do not overstretch the circlips.
• Always replace damaged or stretched circlips.
• The circlips 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
• Loosen the bolts and nuts opposite the tightening sequence.
• Bolts and nuts which secure covers and housings should be loosened and tightened diagonally and in steps if no tightening sequence is specified.
• Especially delicate parts, such as clutch pressure plates, must not be distorted. Loosen and tighten bolts and nuts in stages and in a diagonal sequence.
• The tightening specifications 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.
• Clean the threads of bolts that were applied with locking fluid using a wire brush. Install the bolts using liquid locking fluid (AMV 185 101 A1).
• Clean the threaded holes of the self locking bolts or for the bolts coated with locking fluid. Otherwise there is a risk that the bolts will shear the next time they are removed.
Bearings
• Install needle bearings with the lettered side (thicker metal) facing the fitting 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 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. 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.
• 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 outer friction surface - arrow 2 - and the inner friction surface - arrow 3 - for grooves and scoring.
• Check the taper of the drive gear for grooves and scoring.
• Lubricate the synchronizer ring with transmission fluid and then install.
Gear Wheels, Synchronizer Hubs and Needle Bearing Inner Races
• Warm the needle bearing inner races to approximately 100 °C (212 °F) using the (VAS 6414).
• Heat the synchronizer hub to approximately 100 °C (212 °F) using the (VAS 6414) before installing. Press on as far as the stop when installing so there is no axial play.
• Heat the gears to approximately 100 °C (212 °F) using the (VAS 6414) before installing. Press on to the stop when installing, so there is no axial clearance.
• Pay attention to the installed location.
Selector Gears
• After installing, check 1st through 6th gear for minimal amount of axial clearance and for ease of movement.
Clutch
• When removing the transmission, remove the slave cylinder without opening the lines.
• If the clutch slave cylinder is removed with the hydraulic line attached, do not press the clutch pedal. Otherwise the piston will be pressed out of the clutch slave cylinder.
• 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.