Did you use anything on the gasket ? If not I would try silicone on both sides of the gasket. First I would use some engine cleaner on the tranny so it is clean .Then look for the leak. It will make it easier to find. If it is the pan use silicone To make a better seal. And do not over tighten the bolts , that is how the sealing surface on the pan gets bent and then it will not seal properly. shawn