| Subject: | Allison® Transmission Service Repairs |
| Models: | 2003-2008 Chevrolet Kodiak C4500-C8500 Series Models |
| 2003-2008 GMC TopKick C4500-C8500 Series Models |
| with Allison® 1000-2400 Series Automatic Transmission |
This bulletin is being revised to add the 2008 model year. Please discard Corporate Bulletin Number 02-07-30-042B (Section 07 - Transmission/Transaxle).
Information on Warranty Repairs for Chevrolet Kodiak and GMC TopKick Trucks with Allison® 1000-2400 Series Transmissions
Allison® 1000-2400 Series transmissions installed in Chevrolet and GMC medium duty trucks, C4500 through C8500 series, may only be serviced by franchised Allison® transmission dealers. Without the Allison® franchise, neither light or medium
duty dealers can perform warranty repairs on Allison® transmissions in C4500 through C8500 Series trucks.
Service diagnostic and DTC information is not currently available for the C4500 and C5500 vehicles in Service Information (SI). However, the diagnostics and DTC information for the Silverado or Sierra HD 2500 or 3500 vehicles with the Allison® transmission
may be used.
| • | The Tech® 2 will communicate with the Transmission Control Module (TCM) to read and display the DTCs and perform interactive tests. |
| • | TCM reprogramming, if it becomes necessary, is the warranty responsibility of Allison® dealers. |
| • | TCM replacement is the warranty responsibility of Allison® dealers. |
| • | Transmission Assembly replacement is the warranty responsibility of Allison® dealers, and assemblies are not available from General Motors Service Parts. |
Allison® Dealer Locations
To locate an authorized Allison® dealer or distributor, visit the Allison® website at www.allisontransmission.com and use the Sales and Service locator.
GM dealers that are interested in becoming an Allison® dealer should contact their local Allison® distributor to determine the requirements needed to become a franchised service repair facility.
Warranty Information
Labor operations have not been established in the GM warranty system to pay for internal repairs to the Allison® transmission.
The following associated repairs may be performed by GM dealers as necessary.
| • | Vehicle wiring harness attaching to the transmission |
| • | Transmission oil cooler and oil cooler lines |
| • | Transmission fill tube and/or indicator |
