How do I get exhaust bolts out?
Q. What’s the best method of getting exhaust bolts out? I have two Allen head studs and the heads inside are rounded off.
mjhammer92, MCN forums
A. If you can get to them OK then you can hammer a Torx bit into the rounded off hole. Go for a bit one size bigger than the Allen bolt, so it can bite into the burred edges.
Once it’s firmly in place, apply some heat to the area where the bolt goes in, and ease the Torx bit back and forth gently until you start to get some movement. You can do this with an extension bar or two and a T-bar.
If you have plenty of room to work, then try a good quality pair of Mole grips, use some heat and work it back and forth gently (so as not to snap the bolt or head off) until you get movement.