Siezed exhaust flange studs
 

04 S 6 spd
Exhaust flange. Any suggestions how to get these stud bolts outs?Are they a tapered fit, a key way or just rusted in? Thats penetrating oil on the studs now.
I broke them when I twisted them off back in February to remove the engine.

http://986forum.com/forums/uploads01...1378917020.jpg

They should hammer out easily.

Bypro, thats what I was hoping but is not the case.
The thin head of the bolt is round not hex, could it be a bolt with splines on it?I don't see any spot weld on it, it is factory original.
One of the three flange nuts is spot welded to the flange.

Yes it is splined with a interference fit. Maybe you can support the flange around the bolt with a pipe or socket enough to use a BFH. :matchup:

I used grinder and drill out

thanks Bypro, the pic shows what i've tried so far. With this 3 " clamp and penetrating oil and stricking the edge of the flange with a hammer still no luck. Its been under pressure for 1.5 hrs now. After your post, I like the BFH but can't support the muffler, I removed the little 3" clamp and now have a 8" clamp and tightened with a pipe. Still no movement.

What about grinding the head off and drilling out the stud?

If I need Oxy Acetylene I'll have to wait until tomorrow and take the whole muffler assembly to a welding shop.

http://986forum.com/forums/uploads01...1378933229.jpg

Thanks Trey T that will be my project for this evening.

upgrade it to spring bolt/nut type that Honda uses for their exhaust systems. You can find it locally

Heat the surrounding area around the stud cherry hot and hammer it out. It is the easiest way. I have done dozens of them this way.

Yes Bypro it was splined and the spline is the full depth of the flange. I cut them off and drilled them out, I wish I had oxy acteylene.
Trey T I'll check with Honda tomorrow.

Here is the head of the bolt and a portion of the splined area of the bolt.

http://986forum.com/forums/uploads01...1378950206.jpg

you don't have to get it from the stealership Honda, get it from autopart store like autozone

I used 8x30x1.25 bolt (8 hardness) with copper nuts, and copper never-seize. At the auto parts stores and honda and vw I could not find an exhaust bolt of this size. They did have studs but no bolts. After talking to one of the muffler shops they said a #5 or #8 bolt is good, DON'T use a stainless bolt.