Go myself backed into a corner trying to fit new CATs.

So a couple of questions:-

The flange nuts were of course seized, in removing they were pretty much destroyed



Anyone know what thread-size they are and a supplier.?

Trying to be prepared I bought some a new stud & nut kit from RA, however these are M10 and do not match the stock ones.

So next question has anyone ever removed the old studs and if so how did you manage it?

Any help much appreciated...

 

M10 x 1.5

 

M10 x 1.5 is what I got from RA, just seemed a little off.

Thanks for the link, the Dorman SS ones seem much better👍

Still faced with extracting the old ones 🤔

 

the only way I've been able to get them out is with a torch and heating up the flange until red, its hard to do with the manifolds on the truck

Neal

 

I just changed out the motor mounts on a 2015 escalade and ended up having to remove the manifolds, one of the flange nuts did the same thing. I was able to chase the threads and salvage the stud so didn't need to replace it, the threads were as hummerz posted, M10x1.5, I also questioned the size and thread pitch as the nuts were a bit hard to thread on so I chased the treads on the studs being very careful to make sure the die was not cutting new threads just cleaning them and then all was good.
Not saying the studs on the H2 would be the same as an escalade but from my experience GM has been pretty consistent with that size on the exhaust manifolds.

Neal

 

^X2 HEAT flange stud thread area until glowing red then grab a set of vise grips or stud extractor to remove. Spins out easy when when red hot.

 

Indeed tough to do...

 

 

Useful info, thanks for that🙏👍