Broken / Frozen Exhaust Flange Bolts

[DiverRay]

Once the old stud is out, just run the proper tap into the hole. All you are trying to do is clean up the threads, NOT start a new one!! I use a small adjustable wrench to turn the tap.

[erithanis]

so I discovered that the P.O. has completely shot the header threads for one of the stud holes. I won't have time to deal with it until I'm back in West Covina, CA. But if anyone in that area has a drill press I can use I'd appreciate it a lot as I'm going to have to re-thread that hole.

my first attempt at the one seized stud will be with some JB Weld epoxy to get the nut adhered to it for torque. With luck that'll be enough, though I can probably get my uncle to try welding on the nut when I get back to SoCal if it doesn't.

[Gyrogearloose]

Hopefully, you've got this problem solved already. I'd like to be of some help if you haven't. I've had good luck with removing seized studs/bolts with the drilling method. The use of heat, penetrating oil, the proper tools...AND SAFETY EQUIPMENT, will assure a successful outcome. First I would wear goggles or a face shield; you could experience flying bits/shards of metal..hot/molten or otherwise. Long sleeves, tight fitting leather gloves all help. Now down to business. If the stud has broken off square, good deal. If not, you want to grind it down to a flat surface to begin with, as you need this even base to ensure you will properly center punch and drill. Make a target dot with a small tipped felt pen exactly on center of the stud. (With the felt pen you can make several tries until you get it right.) Hope you have good light and good vision. Then using this dot, take a center punch and make the dimple. Oh!..not quite in the center?..OK, you can herd the dimple to the center by angling the center punch in the right direction and tapping it with the hammer. Ok, throughout, you need to keep applying penetrating oil; this is a good time to do it again. By the way, heating the stud with a small tipped oxy/acetylene torch with help suck this oil down along the stud walls. The trick to drilling is to use quality/SHARP drill bits, and the proper alignment. Begin small and go larger untill you're almost at the stud diameter. Drill exactly in line with the stud, as close as you can. Take care here as this is most important. Also treat small drills very gingerly, you don't want to break one off in the stud. Anyway, measure the other studs and tape off your drill bit to act as a guide so you'll know when you're deep enough. When the threads of the hole start to appear, it's time to use taps. There are two kinds you may want to use: a starter tap, and a bottom tap. Begin with the starter tap, it will help you get down the hole without jamming up. Don't force a tap. If it starts to jam up, back out and clean it. Blow the hole out with air, add some more oil and start again. Use a tap handle to do the twisting. Anyway, my two cents worth. Good luck.