General Information: Components

Guided Fault Finding, On Board Diagnostic (OBD) and Test Instruments

• Before servicing the Haldex clutch, determine the cause of the damage as exact as possible using the vehicle diagnosis, testing and information system in "Guided Fault Finding", "OBD" and "Test Instruments".

-- Vehicle diagnosis tester, connecting and selecting functions. Refer to Vehicle Diagnosis Tester, CONNECTING AND CHECKING .

Special Tools and Equipment 

For a complete list of special tools used in the Repair information refer to ServiceNet under Special Tools and Equipment.

Rear Final Drive 

• When replacing rear final drive, axle oil level and Haldex clutch fluid level must be checked and topped off, if necessary, refer to REAR FINAL DRIVE IDENTIFICATION and HALDEX CLUTCH OIL LEVEL, CHECKING OR FILLING .
• For Audi A3 capacities, refer to .
• For Audi TT capacities, refer to CODE LETTERS, ASSEMBLY ALLOCATION, RATIOS AND CAPACITIES .
• For the correct transmission fluid specification, refer to the Fluid Capacity Tables.
• Clean the contact surfaces when installing the brackets as well as any waxed components. Contact surfaces must be free of grease and wax.

O-rings, Gaskets, Seals 

• O-rings, gaskets and seals must be replaced.
• Always clean separation surfaces.

Prior to installing: 

• Lightly lubricate the shaft seals on the outer circumference and the area between sealing lips -arrow- with a thin layer of grease before installing.
  Fig 1: Identifying Oil Seals Sealing Lips

  Courtesy of AUDI OF AMERICA, LLC
• The open side of the seals point toward the fluid to be sealed in.

After installing: 

• Axle oil level in rear final drive, checking, refer to REAR FINAL DRIVE IDENTIFICATION .
• Oil level in Haldex clutch, checking and filling, refer to HALDEX CLUTCH OIL LEVEL, CHECKING OR FILLING .

Fasteners 

• Do not overstretch the circlips.
• Always replace damaged or stretched circlips.
• The circlips must fit completely inside the groove.
• Replace the adapter sleeves. Installed position: Slit -A- should in line with the line of force -arrow-.
  Fig 2: Identifying Locking Elements

  Courtesy of AUDI OF AMERICA, LLC

Bolts and Nuts 

• Loosen and tighten the cover and housing bolts or nuts in a diagonal sequence.
• Parts which are particularly sensitive to distortion must be kept straight when removing and installing; loosen or tighten diagonally in stages.
• The tightening specifications stated apply to non-oiled nuts and bolts.
• Always replace self-locking nuts and bolts.
• Only wax all the contact surfaces on the threaded connection bolts and nuts after installing.

Bearings 

• Install needle bearings with lettered side (thicker metal) racing the fitting tool.
• Insert all the bearings in transmission with gear oil.
• Replace all the tapered roller bearings that are on the same shaft. Use tapered roller bearings from the same manufacturer.
• Heat the inner races to approximately 100 °C (212 °F) before installing.
• Do not interchange outer and inner bearing races with those from other bearing of the same size. The bearings are paired.

Adjusting Shims 

• Measure the adjusting shims at several locations with a micrometer caliper. Tolerance variations make it possible to find the exact shim thickness required.
• Check for burrs and damage.
• Only install perfect shims.