Drive Line Vibration/Moan Noise at Highway Speeds (Re-Index Propeller Shaft at the Differential Flange)

Some customers may comment on a vibration or moan noise in the vehicle at highway speeds.

The most likely cause is that the propeller shaft is incorrectly indexed at the rear differential flange.

Follow the service procedure below for diagnosis and correction:

1. Road test the vehicle and verify the customer's concern.
2. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information. Refer to SI Document ID #813128.
3. Verify that the blue paint dot on the differential flange is aligned with the white paint dot on the propeller shaft.

•	If the paint dots are aligned and the vehicle exhibits a vibration concern, continue with Diagnostic Starting Point - Vibration Diagnosis and Correction SI Document ID #663404.

•	If the paint dots are not aligned continue with the next step.

4. Remove the drive shaft to differential flange bolts.
5. Align the blue and white paint marks.

Important: If reusing the propeller shaft-to-flange nuts and bolts, to ensure proper adhesion and fastener retention, the threads must be free of debris prior to the application of the threadlocker.

6. Thoroughly clean the threads using denatured alcohol, or equivalent, and allow to dry. Apply Threadlocker, GM P/N  12345493 (Canadian P/N 10953488), or equivalent, to the propeller shaft-to-flange bolt. Ensure that there are no gaps in the threadlocker along the length of the filled area of the bolt. Allow the threadlocker to cure approximately 10 minutes before installation.



7. Install the propeller shaft CV joint-to-differential flange bolts.

Tighten
Tighten the bolts in sequence (1-6) to 60N·m(44 lb ft).

8. Lower the vehicle.
9. Road test the vehicle and verify the repair.

For vehicles repaired under warranty, use: