BMW X3 (F25) Service & Repair Manual: Front axle gearbox

• Check/change front axle differential oil
• Removing and installing/replacing front axle differential
• Removing and installing/replacing left or right output shaft

Check/change front axle differential oil

Special tools required:

• 00 2 080

IMPORTANT: If oil is filled up to the lower edge of the oil filler opening, the front axle differential would be overfilled and in rare individual cases oil could emerge from the ventilation opening on the front axle differential.

After draining front axle differential oil or when carrying out the initial filling of a new replacement front axle differential, the transmission must be filled with 600 ml oil.

Use only the approved front axle oil in the front axle differential.

Failure to comply with this requirement will result in serious damage to the front axle differential!

NOTE: Only change oil when front axle differential is at normal operating temperature.

Necessary preliminary tasks:

• Remove REINFORCEMENT PLATE.

Checking and correcting the front axle differential oil level:

The front axle differential is subject to oil filling over its lifetime. An oil-level adjustment is not needed during a service. If there is a visible release of oil or after a repair to the front axle differential, follow the instructions in Front axle differential oil replacement .

Removing and installing/replacing front axle differential

IMPORTANT: For the initial filling of a new replacement front axle differential, the gearbox is filled with 600 ml oil! If oil is filled up to the lower edge of the oil filler opening, the gearbox would be overfilled and in rare individual cases oil could emerge from the ventilation opening on the front axle differential.

WARNING: Danger to life! SECURE ENGINE IN INSTALLATION POSITION to prevent it from falling down.

Necessary preliminary tasks:

• Secure ENGINE IN INSTALLATION POSITION .
• Drain and dispose of FRONT DIFFERENTIAL OIL.
• REMOVE left output shaft.
• REMOVE right output shaft.
• REMOVE front propeller shaft.
• Lower FRONT AXLE SUPPORT.

IMPORTANT: Grip front axle differential firmly while releasing last bolt in order to avoid damage caused by the differential falling.

Removing and installing/replacing left or right output shaft

Special tools required:

• 31 5 110

NOTE: If the wishbone is detached from the front axle support, it will be necessary to carry out the wheel alignment procedure.

Necessary preliminary tasks:

• Remove FRONT WHEEL .
• Remove front UNDERBODY PROTECTION.
• Remove ANTI-ROLL BAR LINK FROM ANTI-ROLL BAR.

IMPORTANT: The radial shaft seal for the output shaft should be replaced every time the output shaft is removed and installed.

IMPORTANT: Circlip (1) in the bearing support/front differential must be replaced when fitting the output shaft!

If necessary, remove visual protection cap (1).

Release collar bolt (1), press brake pedal to floor for this purpose.

Installation note:

• Renew collar bolt (1) and compression spring (2).
• Pay attention to installation position of compression spring (2).
• Keep collar bolt and spur toothing of bearing/propeller shaft clean and free of grease
• Follow installation note of the spur gearing.

IMPORTANT: Note on installation must be observed without fail!

Installation note:

• Spur gearing of bearing (1) and output shaft (2) must be installed form-fit (tooth in tooth)!
• Tighten collar bolt and compression spring by hand.
• Check whether spur gearing is locked tooth in tooth by reciprocally rotating wheel hub/output shaft.
• Once a form-fit has been ensured, tighten to final torque.

Detach TIE ROD END FROM SWIVEL BEARING .

Release WISHBONE ON FRONT AXLE CARRIER.

Turn swivel bearing to one side.

Remove output shaft from swivel bearing/wheel bearing.

Front differential: Knock out output shaft (2) from the front axle differential with an aluminium drift (1).

Installation note: Renew RADIAL SHAFT SEAL IN FRONT AXLE DIFFERENTIAL.

Coat sealing lips with front differential oil.

Replace circlip and slide in output shaft, overcoming resistance of circlip. Output shaft must snap audibly into place.

IMPORTANT: High installation forces indicate that the gearing on the output shaft/rear axle final drive side gear are damaged/deformed! Check gearing and replace components if damaged.

Bearing support: Press output shaft with special tool 31 5 110 out of bearing support and remove.

Installation note: Replace SHAFT SEAL IN BEARING SUPPORT and coat sealing lips with front differential oil.

Replace circlip and slide in output shaft, overcoming resistance of circlip. Output shaft must snap audibly into place.

IMPORTANT: High installation forces indicate that the gearing on the output shaft/rear axle final drive side gear are damaged/deformed! Check gearing and replace components if damaged.

After installation:

• Check OIL LEVEL IN FRONT AXLE DIFFERENTIAL, correct if necessary.
• Carry out wheel alignment procedure .

REPLACING AN OUTPUT SHAFT GAITER (ON TRANSMISSION SIDE) (OUTPUT SHAFT REMOVED)

NOTE: Procedure is described in BOTH OUTPUT SHAFT GAITERS.