Allison LCT1000 Valve Body Differences and Identification - keywords automatic chuggle DTC delay drive engage forward gear movement reverse slip shift shudder solenoid TCC
| Subject: | Allison LCT1000 Valve Body Differences and Identification |
| Models: | 2001-2005 Chevrolet Silverado |
| 2001-2005 GMC Sierra |
| Equipped with Allison LCT1000 (RPO M74) Transmission |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Dealers may comment that the valve body for the Allison LCT1000 transmission they received looks different then the one they removed.
Recommendation/Instructions:
Part number 29541572 will be used on 01 - 05 models. The addition of the Step Main auxiliary valve body and "G" solenoid will not affect transmission performance on the 01 - 03 models due to a different TCM calibration and the "G" solenoid not being electrically connected to the TCM wire harness. Part number 29541572 will include 4 bolts to allow proper installation of the valve body to 01 - 03 transmissions.
Note: The Step Main auxiliary valve body is located on the front left corner of the valve body when viewed in the truck standing behind the transmission facing toward the front of the vehicle.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
