If it is indeed the pan... The way I do them is cork gasket or the rubber reinforced cork, clean and flattent he pan flanges. There can be no oil of any kind on the pan or tranny's gasket flanges. Clean with brake cleaner and clean cloth/rag. I do not ever use silicone on the tranny pans. Over time, the gasket will loosen up with it and it doesnt grab the metal like it should with silicone on it. If you've done afew services on them you might note it's usually a bear to remove a cork gasket when it's been installed dry and on for a while. Also, when the pan goes bcak on, you need to be careful to tighten evenly going accross the pan. Not just around the outer edge in one direction. Start with one bolt, snug it, then go accross the pan to the second, snug it, go back accross to the next one, etc until they are all snug. then go around again going maybe 1/2 turn tighter and they are done. They should not be torqued very high. The spec is only 150 inch pounds. that's only a hair over 12 foot pounds...
