CurlyDE

I was pulling the engine out of my '83 this past weekend and had some problems getting the passenger side of the cross member removed. I ended up snapping off one bolt in the frame rail. The other bolt came out, but about half of the threaded area has been destroyed.

Any suggestions on removing the broken bolt? Can these be re-threaded and if so, what is the suggested method (heli-coil, etc ...)?

theedge

I guess there isnt any bolt sticking out of the hole?

If there is, Craftsman Ez-Outs (they look like a dark gray rachet socket kinda thing). If theres nothing poking out, Craftsman Bolt-Outs (these guys look like a wicked barbed drill bit).

CurlyDE

There is nothing poking out of the rail ... the remaining portion of the bolt is completely inside. I will try the Bolt-Outs that you mentioned.

theedge

Be VERY careful and follow the instructions to the letter. Do a few searches here on rennlist, IIRC theres a few other threads about them with some good info (all over rennlist, even in the 911 forums).

I havent used those ones (ust the Ez-Outs for rounded off bolt heads and such), but I have heard that if you arent careful they can snap off in the bolt. At that point youll be banging your head on the oil ban in fury.

They work by drilling a hole into the broken bolt, then sticking that bit in there and using it to spin the bolt out.

IceShark

Hold on! I think you need some other advise.

Start calling around to your local machine shops. They can send a guy out to solve fairly easy and more or less cheap. While those crossmember bolts are fairly large diameter if you snap an easy out off in there, then you have a problem. That is hardened tool steel you just added to the equation.

But if you are still going to go the DIY route I'd heat up the bolt with a torch before I put an easy out in the stub. You want to get that metal moving and break whatever corrosion socked in the bolt in the first place.

iloveporsches

Yeah, I've snapped an easy-out in a bolt before. Took a good 3 hours to drill out, and went through at least 2 dozen drill bits. Not fun.

IceShark

That is when you are supposed to go buy a diamond drill bit or use one of those fancy plasma burning machines. Sort of hard to turn your car upside down to put on the table though.

Moral of story is the odds are far, far, far, far, far higher that you will snap off an easy out than have it work right. Especially if you are not skillled in the task.

RedlineMan

Hey Don;

I don't think you stand much of a chance getting it out with an easy-out. That is a big honkin bolt, and it is likely cross-threaded or otherwise gauled so that it is effectively welded in there. The fact that the threads are chewed on the other one suggests this as well. If you break a drill or easy-out off in there, you are SCREWED!

Incidentally, heating the bolt will make it WORSE. When you heat something to get something out, you are trying to expand the "host" object so that its grip on the item you are trying to remove is reduced. You'd want to heat the thread insert welded into the frame, NOT the bolt.

Here's what I would do. I've done this before on similar problems, like the center bottom water pump bolt!

- If there is any bolt sticking out at all, I would grind the end flat so you can center-punch it. If there is nothing sticking out, I would start with an incredibly sharp drill bit that is exactly the size of the hole, and with very light pressure I would try to make a conical indentation in the end of it. The hole will center the bit, and this indentation will be your centering point.

- Take a smaller bit, say 1/4" and drill right through the bolt shank. You must drill straight!!! I would then work my way up in size by 32nds if not 64ths until the bolt shank started to disintegrate. If you need to, go buy a good drill index to get all these sizes.

If you are good and lucky, the bolt shank will start to disintegrate and you can sometimes clean all of it out of the hole with a pick. You would then chase the threads with a 12mm tap (1.5 TPI ?) and try a new bolt in there.

If the threads were not very good, I would then drill the hole out to the next nearest size, which would be SAE 1/2" and then tap it for that size.

iloveporsches

The worst part is was that they were pressue plate bolts, meaning I could have just drilled off the stripped heads and slid the thing out easily. Of course, I realized this after breaking the damn extractor.

I highly recommend NOT using easy outs. EVER. They are anything but "easy" and often lead to the job becoming exponentially "harder."

Mike C.

I think Red Line's approach is the best. You can also Heli-coil if the original threads cant be preserved.

Re-animator

Having just dropped the crossmember recently, those are going to be some mighty long drill bits.

Granite 944

I would go the suggestion of Redline's also. It kinda sounds like some PO may have stuck 7/16" SAE bolts in there instead, possibly using an impact wrench to seat them (there is a time and place for impact guns, and knowing there proper use). I DO believe in torque wrenches, and anti-seize. I also strongly suggest not going at it with an easy out, or equivilent also, unless you've got a heck of a lot of experience using them, and know where and when to use them, and this doesn't sound like a good place to use them to me either.

Along with what Redline said, I'd try spraying the threads of the bolt with PB Blaster several times over a day or two prior to starting to drill it out (drill straight and true). I swear by this stuff, but it takes some time to work and get in there and do its thing (just in case it really is just really nasty corrosion problem). Whatever you end up doing, make sure the threads in the frame are in good shape before you bolt the crossmember back up. You sure don't need bolt failure here.

Helicoil or timesert to get back to the original 12mm size will most likely be necessary if the threads cannot be saved. Be sure to size the insert, drill it properly, and install it properly, or you will have wasted a lot of time, money and effort, and put the quest at risk.

Again, like Iceshark said,

"Moral of story is the odds are far, far, far, far, far higher that you will snap off an easy out than have it work right. Especially if you are not skillled in the task."

Boy! I consider that, very much an understatement.

Good luck!

CurlyDE

Hmm, well you guys have scared me enough. I'll avoid the easy outs.

I have not decided whether or not to pay someone or try to drill it out myself. If I can find a good machine shop that is not an hour away ... then I may let them handle it. The place I normally use is a pretty good drive from here.

Luckily, this is merely a project a car ... so the down time is no big deal.

Thanks for all of the suggestions guys. That Rennlist membership pays off just about every week.

Helstrm

While on this subject, Where can I get the replacement bolts for the cross member?