Automatically Shifted Manual Transmission/Transaxle: Description and Operation
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.
A number of generally applicable instructions for individual repair operations, which are otherwise mentioned at various points in this repair information, are summarized here.
Guided Fault Finding, On Board Diagnostic (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 transmission. Refer to the vehicle diagnostic tester.
Special Tools and Equipment
For a complete list of special tools used in each repair group, refer to "Special Tools" ad the end of each repair group.
Transmission
Always make sure that no dirt enters an "open" transmission. Dirt entering an open transmission can cause a malfunction especially with a "open" Mechatronic unit and/or oil pump.
• Do not run the engine and do not tow the vehicle if the transmission front cover is removed or if there is no Direct Shift Gearbox (DSG(R)) oil inside the transmission.
• Always clean the connecting points and the areas around them first, and then loosen them.
• When installing the transmission, make sure the alignment sleeves are correctly seated between the engine and transmission.
• Place removed parts on a clean surface and cover them so that they do not get dirty. Use foil, paper or a lint free cloth.
• Only install clean components: Only unpack replacement parts immediately prior to installation.
• If the transmission is replaced, check the DSG(R) oil level and fill as necessary. Refer to => [ DSG(R) Oil Level, Checking ] DSG(R) Oil Level, Checking, and for the correct specification, refer to the Parts Catalog.
Fasteners
• Do not overstretch the circlips (lock rings).
• Replace damaged or stretched circlips.
• The circlips must fit completely inside the groove.
Direct Shift Gearbox (DSG(R)) Oil
Shake the container before opening.
DSG(R) oil is obtainable as an original part, for the part number, refer to the Parts Catalog.
The oil quality is of vital importance for transmission function.
Do not mix additives into the DSG(R) oil. Do not fill with a different oil.
The drained oil must not be reused again.
Be very careful when working with DSG(R) oil. Dispose of drained transmission oil correctly.
When To Change the Transmission Oil Filter
The oil filter does not need to be changed in every case.
DO NOT replace the filter if:
• The transmission oil cooler or its O-rings were replaced and no coolant has gotten into the oil.
• The selector shaft seal was replaced.
• The flange seal was replaced.
• Leaking Mechatronic covers, DSG(R) clutch or oil pump were replaced.
• The transmission input speed sensor and clutch oil temperature sensor were replaced.
The filter MUST BE replaced if:
• The 60,000 km (37,000 mile) maintenance interval was reached.
• Coolant has entered the oil.
• Metal shavings were found in the oil.
• The clutch is burned or has a mechanical fault.
Oil Drain and Check Plug
A plastic overflow tube is located behind this plug - arrow - (with a 8 mm hex socket head, tightening specification: 3 Nm). Its length determines the oil level in the transmission.
O-rings , Seals and Gaskets
• Replace the O-rings, seals and gaskets.
• After removing gaskets and seals, always inspect the contact surfaces on the housing or shaft for burrs resulting from removal, or for other signs of damage.
• Before installing the seals, lightly oil the outer circumference and fill the space between the sealing lips - arrow - halfway with sealing grease for seal (G 052 128 A1).
• The open side of the seal points toward the fluid to be sealed in.
• Use DSG(R) oil only. Other lubricants cause malfunctions.
• After replacing the seals, O-rings and gaskets, check the oil level and fill as necessary. Refer to => [ DSG(R) Oil Level, Checking ] DSG(R) Oil Level, Checking.
Bolts and Nuts
• Loosen or tighten bolts and nuts for the covers or housings diagonally.
• The tightening specification stated applies to non-lubricated nuts and bolts.
• Use a wire brush to clean the threads of bolts that were installed using liquid locking fluid. Install the bolts using liquid locking fluid (AMV 185 101 A1).
• Clean the threaded holes for the self-locking bolts or for the bolts coated with locking fluid. Otherwise there is a risk that the bolts will shear the next time they are removed.
• Always replace self-locking nuts and bolts.