A transmission fluid leak may be seen on some 2022 Silverado, Tahoe, Suburban, Sierra, Yukon and Escalade models equipped with the 10L80 10-speed automatic transmission (RPO MHS, MHT, MQB, MQC). One or more of the rear case plugs (Fig. 7) on the transmission may be leaking.
Fig. 7
Inspect the rear of the transmission for evidence of transmission fluid at the case plugs. To help confirm the leak source is the case plug, use a light looking from the right side of the transmission between the transmission crossmember and the transmission case.
If one or both case plugs are found to be leaking, remove the transmission crossmember support and mount to gain access to the plugs. (Fig. 8, 4WD shown) Only replace a plug if it is leaking. Refer to the appropriate Service Information for the complete service procedure.
Fig. 8
Remove and discard a leaking plug and then clean the threaded hole of any residual oil with a clean, lint-free shop towel. (Fig. 9)
Fig. 9
TIP: Not all of the residual oil will be removed in the cleaning process. Do not use brake clean-type solvents to clean the threaded plug hole.
Before installing a new plug, apply a small bead of ACDelco thread sealant. (Fig. 10)
Fig. 10
Install the new plug and torque to 11 lb.-ft. Clean around the plug. (Fig. 11)
Complete repairs by reinstalling the transmission crossmember and then checking the transmission fluid level. Add transmission fluid ULV if needed following the procedure in Service Information.
Fig. 11
For additional information and part numbers, refer to Bulletin #22-NA-129.
– Thanks to Tom Ellison and Mark Gordon
Updated January 24, 2023
