When tires are changed from the original equipment size to those adapted to railroad track gage, the Vehicle Control Module (VCM) must be reprogrammed to corret the speedometer reading.
Truck Models C/K 2500: LQ4 6.0 L V8 Engine and MT1 4L80-E Automatic Transmission. The transmission calibration part numbers ae as follows:GT4 Axle | 9358279 |
GT5 Axle | 9358280 |
Reprogramming the VCM is done with a TECH II electronic diagnostic system. Your GM truck dealer has this equipment. Your dealer has the correct calibration identified by the calibration part numbers on the following page and any later updates after this publication.
NEW TIRE SIZE | AXLE CODE | CALIBRATION PART NUMBER |
|---|---|---|
8-19.5 Custom Xtra/Super High Miler 593 Rev per Mile | GT4 (3.73:1) GT5 (4.10:1) | 12577551 12577553 |
8R19.5 Vandura Commercial/School Motor Home Chassis 608 Rev per Mile | GT4 GT5 | 12577552 12577554 |
G133 Unisteel 8R19.5 626 Rev per Mile | GT4 GT5 | 12577555 12577556 |
Please refer to the light duty series GM BODY BUILDER BOOK for further general information regarding vehicle modification. | ||
