got rough shifts real quick and wouldn't change higher than 2nd from memory, warranty paid just on $5K to rebuild and that was probably 5 years ago or more.
was the family car but now just parked in my shed for odd cruise days.
problem was very intermittent, could drive for an hour and it does it once then was fine. hot of cold. 5 minutes in or a hour. nothing constant about the fault.
the gasket/ trans has two bolts on one side and one on the other, under the actual bolts there is no loop or gasket just a gap where a gasket should be. surprised it still sealing.
yes my GT-P also has one (4 speed) going to swap it for a 6 speed auto or manual once i get time.
4 speed has gone once but was rebuild under a aftermarket warranty. standard cooler not big enough was the issue in they say. (the 500hp the car is may have also played a part...lol)