Inspect for the proper gear oil levels prior to performing system diagnosis. Refer to Axle Lubricant Change .

Operate the vehicle turning in tight circles in both left and right directions. A moan, groan, chatter, or a pulsing type concern may indicate a pump, valve, or clutch pack malfunction within the differential assembly.

Worn or loose rear differential mounts

Repair or replace as required.

Loose torque tube bracket or a damaged bracket bushing

Tighten the bracket bolts or replace the bracket as required.

Worn axle shaft constant velocity joints

Replace the constant velocity joints as required.

Worn wheel bearings

Replace the wheel bearings as required.

Incorrect type fluid

Installation of the incorrect type gear oil may create a "moan" type noise within 7 770-25 900 km (3-10,000 miles). Fluid that is "black" in color is to be considered normal and is darkened by the carbon material in the clutch plates.

Replace the rear differential assembly as required.

Fluid replacement will not correct a "moan" condition caused by the use of incorrect oil. Refer to Differential Replacement .

Worn clutch pack friction discs

Replace the differential assembly.