[kaptain]

Joe,

Use this https://www.amazon.com/Loctite-Pneumatic...B003XZB54O. On the threads. Don’t bother trying to find it at the auto parts store. I have tried a lot of stuff to seal hot ATF and this works for me like no other.

Thanks for Richard, another valuable tip. I gathered a lot of knowledge from you. 

I had never heard of or used such a product before, but I just ordered one at the link you provided.