4T40E 4T45E Transmission Slip, No Upshift, No Reverse - automatic clutch drive drum fluid gear housing overdrive overheat shift

When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.

Any or all of the following may occur:

1. No Reverse
2. No 2nd upshift
3. No 3rd upshift
4. No overdrive
5. Will not achieve above 40 mph.
6. Slips
7. Erratic upshifts

Check for the driven sprocket support sleeve spun in housing due to insufficient press fit.

1. Refer to published service procedures.
2. Replace the driven sprocket support with part number 24207143.
3. Check and replace all overheated/damaged components.
4. Clean the valve body.
5. Flush the cooler.

Please follow this diagnosis 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. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.