Repair Information

Repair Information

Using the Repair Manual

Refer to the "7-speed DSG transmission (S-Tronic)" repair manual for all special procedures with the transmission installed, depending on the model. The servicing repair manual either does not describe them or describes them only partially. Both repair manual are needed for a successful repair.

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 service information is summarized here. They apply to this repair manual.

Oil, Environmental and Disposal Regulations

• Handle ATF, transmission fluid and other oils carefully.

• Dispose of drained ATF properly.

• Follow the legal environmental and disposal regulations.

• Follow the information provided on oil packaging.

Transmission

• Follow all the guidelines for clean working conditions. Refer to => [ Clean Working Conditions ] Clean Working Conditions.

• If installing parts that can be used again, clean and check them and replace if necessary.

• During installation, make sure that the alignment bushings are installed correctly.

O-rings, Shaft Seals, Seals

• O-rings, shaft seals and seals must be replaced.

• After removing gaskets, examine contact surface on housing/shaft for burrs resulting from removal or for other signs of damage.

• Clean the housing separating surface thoroughly before assembling.

• Before installing, lightly lubricate shaft seal outer circumference and sealing lips with ATF or gear oil, depending on installation location.

• Coat O-rings lightly with ATF or transmission fluid before installing them. This prevents them from crimping when being installed.

• Always only use approved ATF. Other types of lubrication cause faults to occur in the transmission hydraulics.

• The open side of the shaft seals point toward the fluid to be sealed in.

• After installing, check and fill the ATF level or the transmission fluid level (MTF) for the installed transmission. For the correct transmission fluid specification, refer to the Parts Catalog.

Bolts and Nuts

• Loosen the bolts opposite the tightening sequence.

• Nuts and bolts which secure covers and housings should be tightened in steps according to the specified tightening sequence and method.

• Nuts and bolts which secure covers and housings should be loosened and tightened crosswise in stages if no tightening sequence is specified.

• Always replace self-locking nuts and bolts.

• If nothing else is specified: Use a wire brush to clean the threads of bolts that were screwed in with locking compound. Use locking fluid when installing the bolts. Refer to the Parts Catalog.

• 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.

• The tightening specifications stated apply to non-oiled nuts and bolts.

Circlips, Snap Rings

• Do not overstretch the circlips.

• Replace damaged or stretched circlips.

• The circlips must fit completely inside the groove.

Bearings

• Install needle bearings with lettered side (thicker metal) racing the fitting tool.

• Coat and install the bearings with gear oil or with ATF, depending on the installation location.

• Do not interchange the outer or inner races of bearings of the same size.

• Always replace the tapered roller bearings on one shaft together and use new bearings from a single manufacturer.

Adjusting Shims

• Measure the adjusting shims at several locations with a micrometer. Different shim thicknesses make it possible to select the required thickness precisely; install two shims if necessary.

• Check for burrs and damage. Only install perfect shims.

Mechatronic

There is a risk of destroying the transmission control module (Mechatronic) with electrostatic discharge.

• Always discharge "static electricity" before working with connectors or the Mechatronic. Do this by touching a grounded object, for example vehicle ground, the vehicle or the hoist.

• Do not touch contacts in transmission connector with hands.