Drive Axles, Bearings and Joints: Testing and Inspection

Checking Function Of Front Axle Differential And Transfer Case

Possible faults:
^ Drivetrain blocked
^ Locking of drivetrain when cornering (grinding tires)

To obtain evidence of function of transfer case, carry out following task:
^ Automatic transmission: Move to "N" position.
^ Manual transmission: Shift to "neutral" position.
^ Place car on lifting platform and raise. Wheels must rotate freely.
^ Apply handbrake.
^ Both front wheels rotate uniformly in one direction.

Rotation of both front wheels in one direction: transfer case or front axle differential blocked.
^ Remove front propeller shaft.
^ Check front axle differential for freedom of movement.

Replace front axle differential if blocked.
^ Release handbrake.
^ Both output shafts of transfer case rotate against each other.

Rotation of both output shafts not possible: transfer case blocked.

Replace transfer case.

Front wheels can spin: check transfer case for shaft fracture.

Remove transfer case for this purpose.
^ Withdraw drive shaft and check.

Installation:
Replace radial seal on drive shaft.
^ Reinstall drive shaft after checking.
^ Block drive shaft by hand.
^ Rotate output shaft to final drive. Output shaft to front axle differential must rotate.

If output shaft to front axle differential does not rotate: Replace transfer case.

Note: If no faults have been identified by this function check: check chassis and suspension control systems, e.g. "DSC" (Dynamic Stability Control).