General repair instructions

The maximum possible care and cleanliness and proper tools are essential to ensure satisfactory and successful transmission repairs. The usual basic safety precautions also apply when performing vehicle repairs.

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

Special tools 

Summaries of the special tools used in this information can be found at the beginning of most of the repair procedures

Vehicle jack mode 

Before raising the vehicle on a hoist (with wheels off the ground), first activate the vehicle jack mode → 43 - Self Leveling Suspension

Manual release of the gear selector 

If the battery has been disconnected or is discharged and the vehicle must be towed or pushed, it will be necessary to manually disengage the shift lever from position "P" to position "N" Operating manual release for shift mechanism 

Transmission 

• Observe rules for cleanliness when working on the automatic transmission → Rules for cleanliness when working on automatic transmission .
• Do not run engine or tow vehicle with oil pan removed or when there is no ATF in the transmission.
• If the transmission is removed from the vehicle, secure the torque converter to prevent it from falling out.
• Thoroughly clean all connections and the surrounding area before disconnecting them.

• Before installing the transmission, check the installed depth of the torque converter → Torque converter, removing and installing  .
• When installing the transmission, ensure that the dowel sleeves are installed correctly.
• Place removed parts on a clean surface and cover them. Use sheeting or paper. Do not use fluffy cloths!
• Carefully cover or plug unpacked components if repairs cannot be performed immediately.

• Only install clean parts: Remove packing from replacement parts immediately prior to installation and not before.
• When replacing the automatic transmission, check the following fluid levels and top off if necessary: ATF in planetary gear box → ATF level, checking  , gear oil in front final drive → Front final drive gear oil  , gear oil in transfer case → Transfer case gear oil, checking and topping off . Capacities and specifications → Capacities .
• When replacing the rear final drive, check the oil level in the rear final drive and top off if necessary → 39 FINAL DRIVE, DIFFERENTIAL . Capacities and specifications → 00 GENERAL, TECHNICAL DATA .

O-rings, oil seals, gaskets 

• Always replace Orings, seals and gaskets.
• After removing gaskets and seals, always inspect the contact surface on the housing or shaft for burrs resulting from removal or for other signs of damage.

• Before installing radial shaft seal, fill space between sealing lips - arrow  - halfway with grease G 052 128 A1  .
• The open side of the oil seal faces toward the side with fluid filling.
• Before installing, lightly lubricate outer circumference of seal and sealing lips with ATF or gear oil, depending on installation location.
• Lightly lubricate O-rings with ATF when installing to prevent the rings from being pinched or damaged when assembling.

• Only use ATF for automatic transmission components. Other types of lubrication cause malfunctions to occur in the transmission hydraulics.
• When replacing oil seals, always vary the point at which the sealing lips make contact (use insertion depth tolerances).
• Replace paper gaskets, thoroughly clean sealing surfaces and completely remove old seals.
• After installing, check the relevant fluid levels and top off if necessary: ATF in planetary gear box → ATF level, checking  , gear oil in front final drive → Front final drive gear oil  , gear oil in transfer case → Transfer case gear oil, checking and topping off  , gear oil in rear final drive → 39 FINAL DRIVE, DIFFERENTIAL . Capacities and specifications → Capacities  or → 00 GENERAL, TECHNICAL DATA .

Nuts, bolts 

• Loosen bolts in reverse order of tightening sequence.
• Loosen and tighten nuts and bolts for securing covers and housings in a diagonal sequence and in stages, when no tightening sequence is specified.
• The tightening torques stated apply to non-oiled nuts and bolts.
• Replace self-locking nuts and bolts.

• Clean threads of bolts that were applied with locking fluid cleaned using a wire brush. Then insert bolts with locking fluid AMV 185 101 A1  .
• Threaded holes into which self-locking bolts or bolts coated with locking fluid are screwed, must be cleaned (e.g. tap). Otherwise there is a risk that the bolts will shear the next time they are removed.

Locking elements 

• Do not overstretch circlips.
• Always replace circlips which have been damaged or over-tensioned.
• Circlips must be properly seated in the base of the groove.
• Replace spring pins. Installation position: Slot longitudinal to direction of force

Bearings 

• Lubricate bearings with gear oil or ATF, depending on location.

Mechatronic unit 

• Replace the transmission if any of the shift elements are scorched.

Guided fault finding, On Board Diagnostic (OBD) and test instruments 

Before repair work is carried out on the automatic transmission, the malfunction should be determined as accurately as possible using vehicle diagnostic, testing and information system VAS 5051 in modes of operation "Guided fault finding" , "Vehicle Self Diagnosis" and "Test instruments".