General Repair Instructions

Repair instructions

WARNING! Before commencing work on a running engine, make sure that the selector lever is set to "P" and the parking brake is applied.

The maximum possible care and cleanliness and proper tools are essential to ensure satisfactory and successful transmission repairs. The usual basic safety precautions naturally also apply when carrying out vehicle repairs.
A number of generally valid instructions governing the various repair procedures - which used to be repeated several times are summarized here and apply to all the repair information.

Transmission
- Observe rules for cleanliness when working on transmission.
- Do not run engine or tow vehicle if end cover has been removed or if there is inadequate ATF in transmission.
- Only install clean components: Do not remove replacement parts from wrapping until immediately prior to installation.
- When installing transmission, make sure dowel sleeves are correctly located.
- After installation, check fluid level and top up if necessary: ATF in planetary transmission, and gear oil in front final drive.
Refer to Specifications.
O-rings, oil seals, gaskets
- Always replace O-rings, oil seals and gaskets.
- After removing gaskets, examine contact surface on housing/shaft for burr resulting from removal or for other signs of damage.
- Before assembly, thoroughly clean joint surfaces of housing.
- When installing oil seals, apply a thin coating of ATF to their outer circumference and sealing lip.
- When installing O-rings, coat them with ATF to prevent rings from being crushed during assembly.
- Only use ATF in ATF zone. Other lubricants will cause the transmission hydraulics to malfunction.
- Open sides of oil seals must face fluid side.
- Press in new oil seal such that sealing lip is not at same location as sealing lip of old oil seal (make use of insertion depth tolerance).
- After installation, check fluid level and top up if necessary: ATF in planetary transmission, and gear oil in front final drive.

Bolts and nuts
- Slacken off bolts in reverse tightening sequence.
- Tighten bolts and nuts for securing covers and housings gradually observing specified tightening sequence and method.
- Slacken off and tighten bolts and nuts for securing covers and housings gradually in any diagonally opposite sequence.
- Tightening torques specified apply to nonlubricated bolts and nuts.
- Always replace self-locking bolts and nuts.
- Use wire brush to clean threads of bolts, which are screwed in with locking fluid. Then insert bolts using AMV 185 101 A1.
- Tapped holes into which self-locking bolts or bolts with locking fluid have been screwed must be cleaned (e.g. using thread tap), otherwise bolts could tear off when removed again.

Locking elements
- Take care not to overstretch circlips.
- Always replace damaged or overstretched circlips.
- Circlips must be properly positioned in groove.

Bearings
- Install needle bearings with labeled side (thicker metal) facing fitting tool.
- Depending on fitting location, insert bearing using gear oil or ATF.
- Take care not to interchange outer and inner races of bearings of the same size.
- Taper roller bearings fitted on one shaft must always be replaced as a set using the same make of bearings.

Shims
- Measure shims at several points with a micrometer. Different tolerances make it possible to obtain the exact shim thickness required.
- Check for burrs and damage. Only install shims, which are in perfect condition.

Guided fault-finding
Before commencing any repair work, always perform the guided fault-finding procedure using VAS 5051.

Rules of cleanliness when working on transmission
- Carefully clean all joints and adjacent areas before disconnecting.
- Place parts removed on a clean surface and cover them over. Use sheeting and paper. Do not use fluffy cloths.
- Carefully cover or seal opened components if repairs are not to be performed immediately.
- Only install clean components: Do not remove replacement parts from wrapping until immediately prior to installation.