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Drivetrain - Rear Axle Whine

TECHNICAL

Bulletin No.: 08-04-20-001A

Date: April 10, 2008

Subject:
EI08084 - Rear Axle Gear Whine Noise from HD Pickup Trucks Equipped with 11.50" Ring Gear and MW7 Automatic Transmission (Diagnose Ring and Pinion)

Models:
2008 Chevrolet Silverado 2500HD and 3500 Series Only
2008 GMC Sierra 2500HD and 3500 Series Only

with Allison(R) 1000 Automatic Transmission (RPO MW7) and 11.50 Rear Axle Ring Gear

Built from October 12, 2007 through October 17, 2007

Supercede:

This bulletin is being revised to end the request for engineering information and provide field fix information. Please discard Corporate Bulletin Number 08-04-20-001 (Section 04 - Driveline/Axle).

Condition

Some customers may comment on a gear whine noise from the rear axle assembly.

Instructions

Important:
Do not replace the complete axle assembly. A service replacement ring and pinion gear kit is available.

If a customer brings in a vehicle with a noise from the rear axle assembly follow normal diagnostic procedures in SI. If diagnosis leads to the ring and pinion do not replace the complete axle assembly.

Please submit a Field Product Report if any further vehicles come in with this condition. Thank You to all those who offered your timely and valuable assistance in support of this effort.

Warranty Information





For vehicles repaired under warranty, use the table.





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