4T65-E Automatic Transmission Fluid Leak from Reverse Servo Cover (Replace Reverse Servo Cover Seal)

This bulletin is being revised to announce an improved reverse servo cover seal is available from GMSPO and to advise technicians that it is no longer necessary to replace the reverse servo cover when replacing the seal. The 2005 model year vehicles are also being added. Please discard Corporate Bulletin Number 04-07-30-028 (Section 07 - Transmission/Transaxle).

Some customers may comment on a fluid leak under the vehicle.

A transmission fluid leak may be noted during the Predelivery Inspection (PDI).

A possible cause of a transmission fluid leak usually only during cold ambient temperatures below -6.7° C (20° F) may be the reverse servo cover seal. The reverse servo cover seal may shrink in cold ambient temperatures causing a transmission fluid leak.

Follow the diagnosis and repair procedure below to correct this condition.

1. Diagnose the source of the fluid leak. Refer to Fluid Leak Diagnosis, SI Document ID #634313.



2. If the source of the transmission fluid leak is the reverse servo cover, replace the reverse servo cover seal with P/N 24235894. Refer to Reverse Servo Replacement in the appropriate Service Manual.
3. Clean the area around and below the cover.
4. Inspect the transmission fluid level. Refer to Transmission Fluid Checking Procedure in the appropriate Service Manual.

For vehicles repaired under warranty, use: