Most transmission pan gaskets are made from cork. Cork gaskets will begin to leak over time because the material will actually wick transmission fluid from the transmission pan. Cork gaskets will also leak if the transmission pan bolts have been torqued too tight or if the gasket was contaminated with transmission fluid prior to installation.
Drive the vehicle onto the vehicle ramps, and set the parking brake. Put tire chocks behind the rear tires.
Put on the safety glasses. Place the large drain pan directly underneath the transmission pan.
Loosen the transmission pan bolts with the socket and ratchet while holding the pan in position securely with one hand. Slowly relieve pressure on the drain pan to allow the fluid to drain from the transmission. Finish removing the transmission pan bolts
Pull the transmission pan down from the transmission, and dump the remaining fluid from the transmission pan. Allow the transmission to drip drain; this will help ensure you do not contaminate the new gasket.
Wipe away any transmission fluid on the mating surfaces of the transmission and transmission pan. Place the cork pan gasket over the transmission pan surface and match up the bolt holes. Thread the four corner bolts to help support the pan, and hand tighten all the transmission pan bolts.
Torque down all transmission pan bolts with the small torque wrench to specifications provided by the manufacturer. Replace the transmission fluid lost by adding the manufacturer-recommended transmission fluid through the dipstick check tube.
