Repair Information
Repair Information
To ensure perfect and successful transmission repairs, the greatest care and cleanliness as well as the use of good and proper tools is essential. The usual basic safety precautions also apply when carrying out vehicle repairs.
A number of generally applicable instructions for individual repair operations, which are otherwise mentioned at various points in the Workshop Manual, are summarized here. It applies to this repair information.
Special Tools and Equipment
Transmission
• Thoroughly clean all connections and the surrounding area before disconnecting.
• When installing the transmission, make sure that the alignment sleeves between the engine and transmission are positioned correctly.
• For the allocation of bolts and other components.
• When installing the brackets, as well as other waxed components, the contacts surfaces must be cleaned. Contact surfaces must be completely free of oil and grease.
• After replacing the manual transmission, check oil level and fill with gear oil, if necessary. Refer to => [ Manual Transmission, Checking Gear Oil Level ] Service and Repair.
• Capacities and specifications. Refer to => [ Code, Transmission Allocation, Ratios and Capacities ] Code, Transmission Allocation, Ratios and Capacities.
Shaft Seals, Sealing Rings, O-rings, Seals
• Always replace sealing rings, O-rings and seals.
• After removing gaskets and seals, always inspect the contact surfaces at housing or shaft for burrs resulting from removal, or for other signs of damage.
• Before installing radial shaft seals, lightly oil outer circumference and fill space between sealing lips - arrow - halfway with sealing grease (G 052 128 A1).
• The open side of the shaft seals point toward the fluid to be sealed in.
• When pressing in new shaft seal, make sure the sealing lip does not run on the same point as the sealing lip of the old seal (use insertion depth tolerances).
• To prevent crushing when installing, lightly lubricate O-rings before inserting.
• After replacing seals, O-rings and shaft seals, check the oil level. Refer to => [ Manual Transmission, Checking Gear Oil Level ] Service and Repair.
Sealant
• Thoroughly clean housing joint surfaces before applying sealing compounds.
• Apply the sealing compound (AMV 188 200 03) evenly and not too thick.
• Do not allow sealing compound to enter ventilation openings.
Fasteners
• Do not over-stretch circlips.
• Always replace damaged or over-stretched circlips.
• Circlips must locate properly in the groove.
• Replace spring pins. Installation position: Slit - A - should be in line with the line of force- arrow -.
Bolts and Nuts
• Loosen bolts and nuts in reverse of tightening sequence.
• Bolts and nut, which secure covers and housings, should be loosened and tightened crosswise in stages if no tightening sequence is specified.
• Replace self-locking bolts and nuts.
• The tightening specifications stated apply to non-oiled nuts and bolts.
• Threaded holes into which self-locking bolts or bolts coated with locking fluid are screwed, must be cleaned (for example tap). Otherwise there is a risk that the bolts will shear the next time they are removed.
• For all hose connections, it must be checked that contact surfaces as well as bolts and nuts, if necessary, are to be waxed only after installation.
Mount
• Install new tapered roller bearing as supplied and do not use additional oil.
• Install various bearings (removed tapered roller bearings) into transmission, lubricated with gear oil.
• Heat inner races of tapered roller bearings to approximately 100 °C / 212 °F with the inductive heat unit (VAS 6414) before installing. Press on to the stop when installing, so there is no axial clearance.
• Do not interchange the outer or inner races of bearings of the same size.
• Tapered roller bearings installed on a shaft must be replaced as a set and use same make of bearings.
• Install needle bearings with lettered side (thicker metal) towards fitting tool.
Adjusting Shims
• Use a micrometer to measure the shims at several points. Tolerance variations make it possible to find the exact shim thickness required.
• Check for burrs and damage. Only install perfect shims.
Synchronizer Rings
• When reusing synchronizer rings, do not interchange and always install to the same gear wheel.
• Check for wear and replace if necessary.
• Check groove - arrow 1 - of synchronizer ring - A - or of inner race on flat areas (grooves are worn).
• For coated synchronizer rings, coating must not be damaged.
• If an intermediate ring - B - is installed, check this intermediate ring on outer friction surface - arrow 2 - and inner friction surface - arrow 3 - grooves, scoring and blue coloring (from overheating).
• Check taper of drive gear for grooves and scoring.
• Coat with gear oil before installing.
Gears
• Clean before installing.
• Heat to approximately 100 °C (212 °F) with the inductive heat unit (VAS 6414) before installing. Install all the way so there is no axial clearance.
Gears and Locking Collars
• After installing, check 1st through 6th gear for minimal amount of axial clearance and for ease of movement.
• Damage to the synchronizer ring or gear wheel:
A Worn clutch spline camber on the synchronizer ring or gear wheel
• In comparison: synchronizer ring or gear wheel not damaged:
B Worn clutch spline camber on the synchronizer ring or gear wheel
• Picture of damage on the locking collar:
C Worn longitudinal inner spline camber and the locking collar
• In comparison: locking collar undamaged
D Undamaged longitudinal inner spline camber and the locking collar
Hydraulic
• Do not tilt clutch pressure plate; loosen and tighten one after another in 90° increments.
• To reduce odor caused by a burnt clutch, thoroughly clean the clutch housing, the flywheel and the side of the engine facing toward the transmission.