Perform the all-wheel drive (AWD) system function tests and the drain/refill/drive procedure listed below.
1. Disconnect the clutch pump actuator check valve connector. If the noise is eliminated, proceed to step #2. If the noise is still present with the check valve disconnected, the condition may not be from the rear axle. The valve connector needs to be connected before continuing.
2. Verify that the tires are all the same size, make, and adequate tread depth. Repair as necessary. Drive the vehicle and re-evaluate the original concern and see if it is repaired. If not, continue with step #3.
3. Perform the "AWD System Functional Inspection" tests as described in the published Service Information. If the system fails any of the functional tests, replace the rear axle assembly. Please document on the repair order which test or tests the system failed. If the system passed the functional tests, continue with step #4.
4. Drain and Refill the rear axle with the recommended fluid, P/N 12378514 (88901045 in Canada), as described in the published service procedures.
5. Drive the vehicle for 20 minutes and perform the following maneuvers: