What the title says.
I had an el cheapo jdm sport t70 that started to leak a little oil into the exhaust. I took the turbo apart to try a rebuild, and where the exhaust meets the center doesnt stay tight. I am able to turn it to clock it without loosening the bolts. Did I forget a seal?

 

No

Did you clean the mating surfaces before you put it together?

 

Ya, it had only a little bit of carbon build up, but its clean now. It seems to sit to far down now.

 

If the exhaust heat shield was removed and replaced, thats the problem. Check u get the same shield cause I just saw the same happen on a turbine and that was the solution.