Transfer Case: Description and Operation

Components

Transfer Case and Rear Final Drive

• Make sure that the alignment sleeves between the transfer case and transmission are positioned correctly when installing the transfer case.

• Clean the contact surfaces when installing the brackets as well as any waxed components. Contact surfaces must be free of grease and wax.

• For the correct bolts and other components, refer to the Parts Catalog.

• When exchanging a transfer case, the oil must be filled up to lower edge of the filler hole. Refer to => [ Transfer Case Fluid Level, Checking ] Service and Repair.

• Transfer case capacity, refer to the Fluid Capacity Tables.

• When exchanging a front final drive, the oil must be filled up to lower edge of the filler hole.

• Front final drive capacity, refer to the Fluid Capacity Tables.

• When exchanging a rear final drive, the oil must be filled up to lower edge of the filler hole.

• Rear final drive capacity, refer to Fluid Capacity Tables.

O-rings, Gaskets and Seals

• Replace the O-rings and radial shaft seals.

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

prior to installing:

Coat the outer circumference lightly with oil. Fill the space between the sealing lips - arrow - halfway with sealing grease for seal (G 052 128 A1)






after installing:

• Check the transfer case fluid level, refer to => [ Transfer Case Fluid Level, Checking ] Service and Repair.

• Check the front final drive fluid level, refer to => [ Front Final Drive Gear Oil Level, Checking ] Front Final Drive Gear Oil Level, Checking.

• Check the rear final drive fluid level, refer to => [ Rear Final Drive Gear Oil Level, Checking ] Rear Final Drive Gear Oil Level, Checking.

Fasteners

• Replace the circlips.

• Do not overstretch the circlips.

• The circlips must fit completely inside the groove.

Bolts and Nuts

• Always loosen or tighten the bolts and nuts for covers and housings diagonally.

• The tightening specification stated applies to non-lubricated nuts and bolts.

• Always replace self-locking nuts and bolts.

• Make sure the contact surfaces and visible surfaces on the nuts and bolts are waxed after assembling.

• Use a thread tap to clean all threaded holes containing self-locking bolts to remove any locking fluid residue. Otherwise the bolts could shear the next time they are removed.

Needle Bearing

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

Guided Fault Finding, On Board Diagnostic and Test Instruments

• Determine the exact cause of the fault using the vehicle diagnosis, testing and information system (VAS 5051) in "Guided Fault Finding", "OBD" and "Test Instruments" before replacing the differential lock motor (V304) on a vehicle with a differential lock in the rear final drive.