Owners of 1997-2007 GM cars and light trucks (including Saturn) with the Hydra-Matic 4T65-E automatic transmission may complain about a transmission fluid leak.
The condition may be caused by an improperly torqued channel plate gasket, resulting in transmission oil leaking from the transmission vent. This requires replacing the transmission case cover gasket/channel plate gasket.
Replace the channel plate gaskets #429 and #430. Refer to Case Side Cover Replacement in the Automatic Transaxle – 4T65-E subsection of the service information (SI).
The gasket kit is available as P/N 24206391.