I installed a drain plug kit from NAPA for my 4L60E Transmission Pan. There is a small leak and I drained the pan. Removed the pan and removed the drain plug, looks like I may have overtighten the nut and flared the teflon gasket. The gasket looks pretty cheap and if you get the nut really tight, do you need the gasket? If the gasket is needed, how tight do you tighten the nut? It doesn't take much to mess up the gasket.