General Repair Information
The greatest possible care and cleanliness and tools that function properly are important requirements for an efficient and successful final drive repair. Of course the general safety precautions also apply when carrying out repair work.
A number of generally applicable instructions for individual repair procedures, which are otherwise mentioned at various points in the Service Information, are summarized here. Refer to GENERAL REPAIR INFORMATION . They apply to this Service Information.
Guided Fault Finding, OBD and Test Instruments
- Before servicing the all wheel drive clutch, determine the cause of the damage as best as possible. Refer to Vehicle Diagnostic Tester in the "Guided Fault Finding" modes "OBD" and "Test Instruments".
To prevent possible injury when performing measuring tests or test drives. Refer to SAFETY PRECAUTIONS .
Special Tools
Refer to Workshop Equipment and Special Tools for a complete list of special tools used in the Service Information.
Disposal Regulations for Oils and Fluids
Dispose of drained oil properly.
- Disposing of used oils and fluids improperly endangers the environment.
- Mixing with solvents, brake fluid and coolant is not permitted.
- Observe the information on oil the packaging.
All Wheel Drive Clutch Oil and Gear Oil
- The final drive and all wheel drive clutch have separate oil circuits.
- The all wheel drive clutch is filled with all wheel drive clutch oil. Refer to the Parts Information for the part number.
- The final drive is filled with gear oil. Refer to the Parts Information for the part number.
- Rear Final Drive Oil Level, Checking or Filling. Refer to GEAR OIL .
- All Wheel Drive Clutch Oil Level, Checking or Filling. Refer to OIL LEVEL, CHECKING .
- Do not mix additives into the transmission fluid.
- Do not reuse drained oil.
Allocation, oil fill and drain plugs. Refer to COMPONENT LOCATION OVERVIEW - DRAIN AND CHECK PLUGS .
Replace the Rear Final Drive
- When changing the rear final drive the gear oil level and the transmission fluid level for the all wheel drive clutch must be checked and filled if necessary. Refer to OIL LEVEL, CHECKING .
- Capacities. Refer to (2015) Fluid Capacity Tables / (2016) Fluid Capacity Tables / (2017) Fluid Capacity Tables .
- Specification. Refer to the Parts Information.
- Clean the contact surfaces when installing brackets and waxed components. Contact surfaces must be free of wax and grease.
O-Rings, Gaskets, Seals
- O-rings, gaskets and seals must always be replaced.
- Once a seal or gasket has been removed, check the contact surface on the housing or shaft for burrs and damage caused by the removal. Repair as necessary.
- Always clean separating surfaces.
Before installing:
- Before installing the gaskets, lightly oil the outer circumference and fill the space between the sealing lips -arrow- halfway with Grease :G 052 128 A1 . Flange/driveshaft outer seal
- Before installing the flange shaft/driveshaft shaft seal, lightly lubricate the outer circumference and the space between the sealing lips with all wheel drive clutch oil.
- The open side of the gaskets point toward the fluid to be sealed in.
After installation:
- Check the gear oil level in the rear final drive. Refer to GEAR OIL .
- Check the oil level in the all wheel drive clutch and fill. Refer to OIL LEVEL, CHECKING .
Retainers
- Do not stretch the circlips.
- Always replace damaged or stretched circlips.
- The circlips must rest at the bottom of the groove.
- Replace the adapter sleeves. Installation position: the slot -A- should align with the line of force -arrow-.
Bolts and Nuts
- Loosen the bolts or nuts opposite the tightening sequence.
- Nuts and bolts which secure covers and housings should be loosened and tightened diagonally and in steps if no tightening sequence is specified.
- The tightening specifications given apply to unoiled bolts and nuts.
- Always replace self-locking bolts and nuts.
- Use a wire brush to clean the threads of the bolts that were installed with locking fluid. Then insert the bolts with Locking Fluid :AMV 185 101 A1 .
- Clean the threaded holes for the self-locking bolts or for the bolts coated with locking fluid. (for example with a thread tap). Otherwise there is the risk that the bolts could break off the next time they are removed.
- Only wax all the contact surfaces on the threaded connection bolts and nuts if necessary after installing.
Bearings
- Install needle bearings with the lettered side (thicker metal) facing the fitting tool.
- Insert the bearings with oil.
Shims
- Measure the shims at several locations with a micrometer caliper. Tolerance variations make it possible to find the exact shim thickness required.
- Check for burrs or damage.
- Only install perfect shims.