Locking Differential Diagnosis

Locking Differential Diagnosis

1. Block the right front and rear wheels.
2. Turn the Ignition ON - Do not start the engine.
3. Place the transmission in NEUTRAL.
4. Shift the transfer case into 4 LOW.
5. Engage the differential lock switch.
6. Raise the left front wheel off the ground. refer to vehicle lifting.
Support the left front wheel with safety stands.
7. Raise the left rear wheel off the ground. refer to vehicle lifting.
Support the left rear wheel with safety stands.
8. Attempt to rotate the left rear wheel 1 full revolution clockwise and counterclockwise by hand.
^ If the wheel does not rotate 1 full revolution in either direction, the locking differential is engaging properly.
^ If the wheel rotates more than 1 revolution in either direction, the locking differential is not engaging properly.
9. Disengage the differential lock switch.
10. Attempt to rotate the left rear wheel 1 full revolution clockwise and counterclockwise by hand.
^ If the wheel rotates 1 full revolution in either direction, the locking differential is disengaging properly.
^ If the wheel does not rotate more than 1 revolution in either direction, the locking differential is not disengaging properly.
11. If the locking differential is not functioning properly, remove the differential and determine the cause of failure. Refer to Differential Replacement and Locking Differential Disassemble.