EI08084 - Rear Axle Gear Whine Noise from HD Pickup Trucks Equipped with 11.50 Inch Ring Gear and MW7 Automatic Transmission (Engineering Information)
| Subject: | EI08084 -- Rear Axle Gear Whine Noise from HD Pickup Trucks Equipped with 11.50" Ring Gear and MW7 Automatic Transmission (Engineering Information) |
| Models: | 2008 Chevrolet Silverado 2500HD and 3500 Series Only |
| 2008 GMC Sierra 2500HD and 3500 Series Only |
| with Allison® 1000 Automatic Transmission (RPO MW7) and 11.50 Rear Axle Ring Gear |
| Built from October 12, 2007 through October 17, 2007 |
| Attention: | Proceed with this bulletin ONLY if the customer has commented about this concern AND the EI number is listed in GMVIS. Otherwise, disregard the bulletin and proceed with diagnostics found in the published service information. THIS IS NOT A RECALL. Refer to Corporate Bulletin Number 04-00-89-053B for more details on the use of Engineering Information Bulletins. This request only relates to Pickup Trucks equipped with the Allison® 1000 Automatic Transmission (RPO MW7), 11.50" rear axle and vehicles built from October 12, 2007 through October 17, 2007. |
Condition
Some customers may comment on a gear whine noise from the rear axle assembly.
What Action to Take
Important: This request only relates to pickup trucks equipped with the 11.50" rear axle and vehicles with build dates from October 12, 2007 through October 17, 2007.
GM Engineering is attempting to determine the root cause of the above condition. GM Engineering would like to receive product feedback on 2008 Chevrolet Silverado and GMC Sierra 2500HD and 3500 Series vehicles exhibiting a gear whine noise from the rear axle assembly that have not been serviced previously for this concern. As a result, this information will be used by engineering to "root cause" the customer's concern and develop/validate a field fix.
Instructions
Important: DO NOT attempt to repair or service the rear axle assembly. It is important that the rear axle is not disturbed.
If a vehicle is encountered with the above concern, please follow these steps:
- Record the VIN.
- Record the vehicle build date.
- Record the mileage at the time of service.
- Confirm that the noise is coming from the rear axle assembly. Refer to Rear Drive Axle Noises in SI.
- Verify that the axle has not been serviced previously.
- Replace the complete rear axle assembly. Refer to Rear Axle Replacement in SI. Do not drain the fluid from the complaint axle.
- Inspect the new rear axle fluid level and fill. Refer to Rear Axle Lubricant Level Inspection (11.5 Inch Axle) in SI.
- Verify that the condition has been corrected.
- Submit a product report on the repair following the procedure provided in Bulletin 02-00-89-002F.
- Return the complete rear axle assembly to the Warranty Parts Center (WPC), AFTER having received a WPC part return request.
Tip
Once GM Engineering receives your Product Report, the dealership will be contacted to return the complete axle assembly to the WPC.
Engineer Contact Information
If you have any questions, you may contact GM Brand Quality Manager Rich Burrell at 586-947-5740.
Warranty Information
Please claim the following labor operation code when complying with this Engineering Information request.
Labor Operation | Description | Labor Time |
|---|---|---|
F9715* | Engineering Information-Complete Rear Axle Assembly | 3.3 hrs |
*This labor operation number is for bulletin use only. This number will not be published in the Labor Time Guide. | ||
