Colin 90 C2

What is the best way to remove broken exhaust studs?
I have already tried the following:
double nut- not enough thread to secure second nut
vise-grips after soak with rust-buster, even applied some heat
welding a stop on the stud- studs not weldable-must be the finish onthe studs

I'm stuck for the night. Any other ideas??

PC2

How about stud removers ?

Marc Shaw

What about a trusty Dremel and cutting wheel?

Marc

Colin 90 C2

Peter that's why I post. Thanks for the reminder.
I actually have a set of Craftsman bolt removers but the smallest size one was too big, 10mm.
I didn't even think to go look for smaller ones.
I'll see if I can search out a set locally as that is all I have left to have the car back together.

Marc, ordinarily I'd be all over the Dremel but if I cut the remaining stud then I'd have to drill out the stud out of the head and working under the car leaves too much room for error.

LouZ

Colin

Since you stated that the double nut route didn't work, how about a little girth reduction!

Try grinding down both nuts so they are thinner, then hpoefully, you could ust that method.

Worth a try.

springer3

Be careful what ever you do. Break one off flush, and you have real trouble. There is no choice but to start drilling. I recall for the early 911s, someone made a drill guide that let you hand drill the stud without pulling the head and taking it to a machine shop. Break a drill or an "easy out" in the stud, and you are pulling the engine to take the head to a shop.

If you do have to drill out the old one, a step stud or a helicoil give you a stud as good as new.

Good luck

springer3

I have not tried that, but it sounds like a good idea. Just be careful not to overhead the stud. It is heat treated, and will anneal (soften) if heated much past 1200 F (dull red).

Something else to consider: aluminum has almost twice the thermal expansion of steel. Anything you can oo to heat up the head will help loosen the grip on the steel stud. A heat lamp overnight, or a hot-air gun directed at the head should let you raise the temperature to a "one hot" safely. "One hot" means you can count only to one before you have to remove your hand. I is about 140 F.

Colin 90 C2

ok, in addition to what I previously tried, I have now tried
Lisle stud remover- hammer it on and then unbolt- no love, just strips the thread
Craftsman Bolt Out- broke the stud off a little closer to the head, and now I can't remove the broken piece out of the Bolt Out... thank goodness for the replacement warranty.

Indycam, I don't know if silver solder or brazing would be strong enough. The stud seems like it is welded in the head. I did try to weld a nut onto the stud, but I was not getting any penetration. I think the stud material is not weldable.

Lou, I don't think that two 8mm nuts cut in half would have enough strength to loosen the stud, But I may give it a try anyway.

Thanks all for the suggestions. Please keep them coming.

I feel that the drill method will be my last resort.

I'm now on way back to Sears.

Stay tuned... Same Bat channel, same Bat time

springer3

Welding will not work. Even if you got penetration, the stud will be soft or brittle depending on how fast it was cooled. Tempering after heat treating takes hours, and you could not control the temperature well enough even if you knew the required temperature profile.

A good silver solder holds 60,000 psi - about the same as mild steel. You will get several time more torque than you can develop with an easy-out.

If you start drilling into the stud, be sure to use a guide - bought or fabricated. It is nearly impossible to hand guide a drill bit down the center of a stud. Run out into the soft aluminum, and you are done.

JasonAndreas

Is there enough stud showing to rethread and then double nut it again? I have the craftsman stud remover and its useless, I also have the Facom stud remover "set" and they are only slightly better. If you add up the money I spent you end up with what the Snap-On version costs (and what I ended up having to borrow and should have bought in the first place). If at all possible I would attempt to cut a thread on the stud. Your local hardware store should have the dies for less than $5 and cutting/tapping fluid is another few bucks. As a last resort I would drill the center of the stud with a real small carbide bit and then try a left-hand screw remover. If that doesn't work try one that is one size larger. Just start as small as possible so if it doesn't work the first time you still have room to play. I also had to use a blow-torch.

Colin 90 C2

And the final answer is:

I got a new Craftsman Bolt Out and it broke the stud almost flat to the head.
I center punched the stud and started with my numbered drill bits. All the way up till I could put in an easy-out (I could never figure out why they were named as such). Got some grab, but it felt like it was going to break so I backed off and continued stepping up drill sizes till I got to 17/64. About a total of 25 bit sizes. I then tapped the hole. As luck would have it, It came out pretty good and that's when my neighbor called to say that there was a great rainbow outside. My garage must have been under one end of that rainbow.

It's a good thing that I have lots of practice drilling and tapping in many different automotive applications. I would have hated to screw this one up.

Indycam, what is a spark erosion tool. It sounds like I may need to add one to my toolbox.

Thanks for all the ideas.

Now to complete the re-assembly.

dutchcrunch

hello,

i was wondering what the factory used to secure stud with. the reason i ask is because if they used lets say something like high strength red loctite, you have to use heat to soften it before it can be removed. i would call a porsche shop and explain what happened and ask for some tips as to what method they use in this situation. call someone like ottos or look in back of an excellent magazine for a porsche engine rebuilder. you can drill it out but the initial hole must be centered. if i were you and you had to drill i would take a dremel and grind the stud nice and flat, then take a small pointed punch and center punch the stud. start with a small bit and drill and see how you like the centering of drilled hole. if its off use a carbide ball and walk the hole over. the bigger the hole you make without hitting threads will take the load off the screw and make it easier to remove. snap on sells those easy outs that have a large hex head built on to them already and these are good. if push comes to shove and you cannot remove the stud but you were able to keep the hole centered you can always install a heli coil which is professional too. take your time in this matter and you will be able to fix this. if you feel like you cant do it, there has to be some bad *** mechanic from rennlist that could come over and help you out. when you do get this fixed as i am sure you will put a coat of anti seize on the studs for next time. shame on manufacture for not doing this. when i removed my exhaust i soaked the bolt and actually tighted them a little to help loose. its does work. to bad your not closer, i would get that sucker out for you. if you can buy new stud and use for reference as to how far the stud enters the head. i remember seeing a porsche book that showed a dealer having this speacial machine that could drill broken studs out while car was on lift, i think it was in 101 porsche projects or something like that. hell call the dealer they might be able to get it out or better yet have a speacial fixture that they use to to drill perfectly. i am sure you are not the only one that has had this problem, dealer no different. well good luck and take your time it can be done.

dutchcrunch

boy was i late !

Colin 90 C2

Thanks all for the replies. The car is back together and dripping a whole lot less oil now (it still has about 2 drips after a hard run).

The lwt flywheel is impressive, but I will save that for another thread.