Maybe try some permatex brand copper spray sealant on the mating surfaces....let it set a couple mins so it can get kinda tacky,bolt your parts back together and let it set overnight so its good and cured....some people like to use the stuff on head gaskets with no ill effect to help it kinda of grip and prevent a head gasket from slipping and blowing out.....do not start the car or run it until the stuff has cured overnight because it is kind of slippery and gooey when its first applied......I remember it also helped me once with a coupler that was blowing off a pipe.....I sprayed it,let it sit overnight and it didnt blow off anymore.

Hope this helps ya out bro.