Engine Coolant in Transmission

WARNING: This page is about a different car, the 2003 Pontiac Aztek and 2003 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: The antifreeze will deteriorate the Viton O-ring seals and the glue that bonds the clutch material to the pressure plate. Both conditions may cause damage to the transmission.

If the transmission oil cooler has developed a leak allowing engine coolant to enter the transmission, perform the following:

Disassemble the transmission.
Replace all of the rubber type seals. The coolant will attack the seal material which will cause leakage.
Replace the composition-faced clutch plate assemblies. The facing material may separate from the steel center portion.
Replace all of the nylon parts - washers.
Replace the torque converter.
Thoroughly clean and rebuild the transmission, using new gaskets and oil filter.
Flush the cooler lines after the transmission cooler has been properly repaired or replaced.