Well, it didn't take long for me to run into a problem. One side of the header bracket was held on by a regular hex bolt, and the other side looked to be a stud with an acorn nut on it. The hex bolt came off just fine, but the other side was giving me trouble. I sprayed some Sea Foam penetrating oil in there and let it sit. Long story short, the stud snapped.

So I need some advice and information. The stud is broken almost flush, so there are no threads to put a nut on it. It's entirely possible that this thing hasn't been touched in 15 years, so I am wondering if a bolt extractor is even worth a try. Will I just break off the threads, or worse, break the extractor and then really be in trouble? I was thinking of just getting the specs on that stud, drilling out to exactly the right size, then re-tapping. Is there anything else I should try before that, or will I likely have to do it eventually anyway?

Can anyone provide me with the specs on that stud - size, depth & thread pitch and whatever else I might need to know?

On another note, I can't get the bottom nut off the forward heat shield - the stud just spins in the frame. How would one get that off?

naw the second brain cell I have left just started to react to the coffee -those frame through bolt heads on the other side are a lot bigger than a 12mm - anyway after you get the heat shield off put the nuts back on the bolts unless your going to pull the engine

you know I've had to use several different type of bolt extracters, taps, and helicoils in my life - never my fault of course   ya right

but if you have a sears store close to you the new designed craftsman extracters seems to work very well - they come in a 3 pack - different sizes - they have have the extracter on one end and the drill bit on the other - take it slow and I'll bet that bolt will come out of there

then throw it at who ever had it off last time and didn't put antiseize grease on the bolt before they screwed a steel bolt into a piece of aluminum that gets very hot - morons.

Before you drill away what is left of the stud you might consider having a good welder weld a new nut on what is left. The heating and cooling from the welding often loosens the bond between the dis-similiar metals in the process. If it has been cross treaded you can probably still get it out, making  it easier to drill and heli-coil or =. Max

Reelthing wrote on 05/17/08 at 05:54:27:

They're 14mm

You can try the craftman screw extractor.

But I think the type you want to use is the drill a hole, pound in and turn type.

But it couldn't hurt to put a torche to it, then the standard tap at with a hammer and center punch to turn it out.

Most likely, the last idiot to put those in didn't use anti sieze.  And seeing that they replaced one bolt with a hex head type (the acorn nut one is stock) they have had an issue with it before.

Hope you have better luck than I did, the extractor broke.  haven't had the time/money to get it fixed; and my neighbor sold his trailer so now I'll hve to rent a truck/or trailer and bring it round.  the only welder nearby said he would not feel comfortable welding on a bolt, an alignment issue.  At times. I do wish I lived a little closer to some shops.

It broke off flush. I've read about taking a torch to it, letting it cool naturally then going at it with a carbide bit... there really isn't much of the extractor in there. I'm open to suggestions, especially ones that don't require me to pay someone or get a new engine.

Meck, seeing the welding a nut on doesn't seem to be an option at this point. Then use the correct size extractor/easy out and drill the hole parallel to the other bolt, may want want to hand run it back in for a reference. It is OK to go all the way through with a smaller bit first as then you can get some penetrating oil working from the back side also. Patience is the key word. Don't go to big on the extractor, if you do all it does is spread the bolt threads tighter into the head threads.

Trippah, I've had some luck breaking a broken extractor into pieces to get it out. They are fairly hard and will break if you use a pin punch and hammer. Good luck guys, Max

I'm not sure I understand what you guys are talking about - drilling parallel to the other bolt, going along side the broken extractor - I just don't see what I'm supposed to do. Sorry if I'm missing something - I'm just a lowly software engineer, this mechanical stuff is like voodoo...  :'(

The stud for the header pipe broke off nearly flush with the head, so I tried a screw extractor which broke off in the hole I drilled. Today, we tried to weld on a nut, but couldn't get a strong enough weld. At this point, it seems like I'm in the market for a new head.

For now, the shade tree mechanics and I figure that it's not work putting a whole lot of time and money into it and risk completely messing up the head. We were going to try doubling up on new gaskets, sealing them in with high-temp rtv, bolting on the good side of the bracket with a nice hardened bolt, then sealing up the other side with exhaust putty. If it holds and the noise is tolerable, it should at least get me through until I find another head cheap. Does that sound at least passable, or have I suggested the unthinkable?