GM Service Manual Online
For 1990-2009 cars only

Checks

Action

Lubricant is contaminated

Drain and flush the axle housing thoroughly. Refill with the correct lubricant. Refer Rear Axle Lubricant Replacement

The clutch plates are deteriorated

Replace the clutch plates. Refer to Locking Differential Cam Unit Disassemble and Locking Differential Cam Unit Assemble .