General Repair Information
Carefulness, cleanliness and the correct tools are required for transmission repairs to be successful. The usual basic safety precautions also, naturally apply when carrying out vehicle repairs.
Some general repair information that applies to several procedures throughout this information is summarized here.
Guided Fault Finding, OBD and Test Instruments
- Determine the cause of the malfunction as accurately as possible using Guided Fault Finding , OBD and Test Instruments before starting any repairs on the automatic transmission Vehicle Diagnostic Tester.
Oil, Environmental and Disposal Regulations
- Handle ATF, axle oil and other fluids with care.
- Dispose of drained ATF properly.
- Follow the legal environmental and disposal regulations.
- Follow the information provided on oil packaging.
Special Tools and Equipment
For complete list of special tools, refer to the special tools used in the service procedures.
Selector Mechanism Emergency Release
If the battery has been disconnected or is discharged and the vehicle must be towed or pushed, it will be necessary to push the shift mechanism emergency release to shift the selector lever from "P" to "N". Refer to SELECTOR MECHANISM, PERFORMING EMERGENCY RELEASE .
Transmission
- Clean working conditions for the automatic transmission. Refer to TRANSMISSION, CLEAN WORKING CONDITIONS .
- Do not let the engine run or tow the vehicle when the oil pan is removed or when there is no ATF in the transmission.
- With the transmission removed, secure the torque converter so that it cannot fall out.
- Check installation dimension of torque converter before installing transmission. Refer to TORQUE CONVERTER, INSTALLING .
- When installing transmission, make sure that the alignment bushings are fitted correctly.
- When exchanging automatic transmission or components, all fluid levels should be checked and corrected, if necessary. Likewise, all lines must be cleaned. Capacities. Refer to CAPACITIES . Specifications.
Shaft Seals, Sealing Rings, O-Rings, Seals
- O-rings, shaft seals and seals must be replaced.
- After removing gaskets, examine contact surface on housing/shaft for burr 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 seals point toward the fluid to be sealed in.
- Before installing, lightly lubricate shaft seal outer circumference and sealing lips with ATF or gear oil, depending on installation location.
- Coat O-rings with ATF before inserting to prevent crushing rings during installation.
- Always only use approved ATF. Other types of lubrication cause faults to occur in the transmission hydraulics.
- Press in new shaft seal, so that the sealing lip does not run on the same point as the sealing lip of the old shaft seal (use insertion depth tolerances).
- Replace paper gaskets, thoroughly clean sealing surfaces and completely remove old seals.
- After installing, check the relevant fluid levels and fill if necessary. Capacities. Refer to CAPACITIES . Specifications.
Bolts and Nuts
- Loosen bolts in opposite of tightening sequence if another sequence is not specified.
- Nuts and bolts which secure covers and housings should be loosened and tightened crosswise in stages if no tightening sequence is specified.
- The tightening specifications stated apply to non-oiled nuts and bolts.
- Always replace self-locking nuts and bolts.
- Use a wire brush to clean the threads of bolts that were screwed in with locking compound. Install the bolts with Locking Fluid AMV 185 101 A1.
- Threaded holes with self-locking bolts or bolts coated with locking fluid must be cleaned, for example using a thread tap. Otherwise there is a risk that the bolts will shear the next time they are removed.
Circlips
- Do not overstretch the circlips.
- Always replace damaged or stretched circlips.
- The circlips must fit completely inside the groove.
Bearings
- Insert bearing with axle oil or ATF, depending on installation location.
- Replace the transmission if any of the shift elements are scorched.
Control Modules, Electronic Components and Contacts
- Only touch electrical components after discharging static electricity on a grounded object, for example by touching (skin contact) vehicle or vehicle lift.
- Connector contacts in electric connectors, control modules and electrical components must not be touched with the hands under any circumstances. They can be destroyed by static discharge.