The flange between my exhaust manifold and the down pipe keeps coming loose. At first I thought it was because there was no support bracket between the transmission and the center portion of the exhaust. However, I added the missing bracket and it still loosens at the manifold- down pipe after a hundred miles or so.

I noticed there isn't a spring? retainer on the nuts, is this needed? Also, would copper nuts be any better? It seems copper would be softer? Maybe I should use a second set of jam nuts?

Any suggestions would be appreciated .

I double-nut mine.

Stover nuts

Thanks guys!

I have some copper stover nuts, looks like doubling them up with the brass nuts is what I'll try next.