How to get REALLY stuck exhaust studs out.

[Moloko]

Hit a brick wall on the rebuild of my girlfriend's thunderbird. The turbocharger mounting studs are amazingly stuck in. We had to plasma cut the nuts off, and then it took a torch and a stud remover to take out two of them... the other two snapped off in the manifold. Yesterday I tried to drill them out, but the drill bits insta-dulled when they touched the studs. Instead of drilling into the studs, they started going sideways into the manifold, ovaling it out. I was using a drill press. Any other ideas?

[jonzcustomshop]

the only other idea that I can think of is to weld a bolt to the broken off stud(if there is enough left to do that) the heat from welding helps free up the stud,and you have nice bolt that you can wrench on to get it out.

[revkev6]

drilling is the way to go, you just need the right tools to do it. best way to start drilling is with a center drill for a lathe. you can get em right a sears. they don't walk as easily as a standard drill. make sure you use cutting oil and the correct drill speed. too fast will just overheat the bit and harden the bolt more. if the stud broke off at an angle a small end mill might help to give you a surface you can get a drill bit started on. lastly make sure the part is clamped well into the table.

[FiddyFour]

blow it out with the torch if its too far below the surface to weld a washer/nut to get it out.

[Pitt Grease Monkey]

Funny, I just had to deal with three stuck bolts in the past 48 hours.

Here are some tricks you may try before moving on to more destructive means.

Using a propane torch, heat the stud and head. Then touch a candle around the base of the stud letting the wax run into the threads. This sometimes will work the bolt out.

If the stud is broken off inside the hole, send it through a few heat cycles (with propane again) and WD-40. Then roll up a paper towel tightly and stick it in the hole and twist. Yeah, it's crazy, but my friend swears he's removed broken bolts this way that not even the most expensive extractors could get out. I've only seen it work once and haven't gotten it to work myself.

Use a left handed drill bit instead of extractors.

Run a step bit in reverse (new). They have really good edges that tend to grab well.

If you must resort to welding on a nut (believe me, I've been there) use a TIG. Biggest mistake is using a MIG which will cold weld every time because the head acts like an enormous heat sink.

Lastly, drill it out. Buy a diamond tipped bit. Its about the only thing that will get through hardened steel. Otherwise, you may be there for a while.

Also, lastly, the best extractors I've used have been NAPA brand. I don't waste my time with GRABIT or even Craftsman. And definitely not the HF extractors...

Hope one of these tricks helps.

[banjorear]

Originally Posted by jonzcustomshop

the only other idea that I can think of is to weld a bolt to the broken off stud(if there is enough left to do that) the heat from welding helps free up the stud,and you have nice bolt that you can wrench on to get it out.

I've done this numerous times on flatheads, worked everytime. I think the intense heat from the MIG also helps loosen stuff up.

Also, spend the money and order Aero Kroil pentrating oil. This stuff is good. Go to kanolabs.com

[Henry Floored]

Are they they flush or broken below the surface? Coupl'a pointers.... spot face the end of the stud with a small "end mill" chucked up in a drill press or mill if you have one. Then you can center punch and get a good shot at it.

Or you can try one of these drill bits. They are designed to start witout a center punch and will cut through grade 8 steel very efficiently. Available from Kimball- Midwest. PM me if you want some and need help getting them. Follow the link for some really technical info on the bits.

http://www.kimballmidwest.com/Catalo...gText/1017.pdf

[banjorear]

Thank for the info. Never heard of them before. I'll have to check out those bits as well.

[Moloko]

Yeah, its below the surface. I'm going to go to the local hardware store and get a GOOD drill bit and try this again.

Oh, my boss at the garage I work at tried the bee's wax when he was trying to crank the studs out. Still snapped off.

[49ratfink]

my buddy had a jig set up for his mill to hold small block chevy exhaust manifolds. had that fucker out in like 5 minutes.

I learned long ago unless they are broken already never change them.

[Caddy-O]

I might be way off on what you are trying to do, but if I'm understanding correctly, this method may work for you. With the turbo charger mounted on the manifold, tap/ thread the turbo charger hole and then screw in a bolt with a hole drilled through it. I start with a bolt that has a smaller hole and then work my way up to a larger circumference until you can re-tap the holes and chase out the remander of the fragments. This technique will keep your bit centered and allow you to drill out the bolt with no problem. Thing is, you need a high quality machine bit to drill through your seized bolt.

[JaysinSpaceman]

Once you have exhausted all other options, find a business that does EDM (Electric Discharge Machine) machining in your area and have them machine it out. Not a first choice as it is not the cheapest process, but if it is an expensive or Rare part it might be just what you need.

That said I have had good success with the heat and candle wax method if there is enough stud sticking out to grab with vice grips. If not weld a nut on to the stud then while it is still hot add the wax, let it cool for a bit (a hot stud in a cool head will be bound in because the hot expanded stud will be larger then the hole in the cold head) and then it should come out. I wish you the best of luck.

[dare-to-be-different]

I have been there before.

The stud is too short to work on, the drill bit went off track, the metal is too hard for even the toughest bit....

If you are careful you can SLOWLY heat the area cherry red (don't heat it fast or you could crack things), keep it red for a while, making sure the bolt gets that way too.
The idea here is to remove the hardness of the bolt, and make the bolt itself soft.

Let it cool down very slowly. You may even want to play the torch across it every once in a while to keep it from cooling too quickly.

Thats what I do to make the bolt soft enough to drill.

If there is no relatively flat area on the bolt that you can use to start another drill bit, or even get a good punch mark on to, you can use a jig that is easy to make.

Choose a freshly-sharp, tough drill bit that hopefully won't bend and flex too much. That means don't start with a really skinny one, or a long long bit.
Usually I take a thick piece of metal, about an inch thick or so, drill a hole in it with the same drill bit I am going to use, then use it as a drill guide.
I line up the homemade drill guide with the correct hole location I want to follow, clamp the work on the drill press, and very slowly start the drill bit on its job of cutting a new starting hole on the end of the softened stud.

At first you want to just let the drill bit lightly scratch on the end of the old stud until it makes a new dimple to guide the bit down the middle of the stud. You are counting on your drill guide to hold the bit where it needs to be.

If you start drilling hard at the start, the uneven surface on the old stud will push the drill bit over to the wrong course. Be very patient and start very slowly until the bit makes it's own guiding hole or at least a good dimple to follow.

Often, no matter how careful you are, the threads still get a bit messed up or the hole ends up a little oval due to a wandering drill bit.

You can put the threaded hole back into the right location and give it much tougher threads than when new by using a Heli-Coil kit.

Buy a larger drill bit- the size recommended on the Heli Coil box.

You can take your metal block that you used as a drill guide, drill it to a slightly larger size with your new bit, use it as a guide to drill the hole in the right spot, and use it to drill out the buggered up threads in the manifold.

That is a method I use when the hole wasn't really really really out of whack.

If by chance, you let the first attempt that you described get really far out before you realized that it was off track, you will have to assess the situation. One thing I have done many times in the past when people have asked me to move bolt holes in cast iron to adapt different manifolds on their hot rods.

In that case I would freehand drill out an oval hole to make it reasonably round again, thread in a soft bolt, file it flush, and then drill the new hole wherever it needed to be, and tap (heli-coil if you wish) the new fresh hole.

You will have to use your own judgement as you go along.

I like the picture that Caddy-O provided above. If the stud is below the surface, you can use his picture to understand the method I was trying to describe using my drill guide. If the stud is too close to flush to use a guide like that, you may have to use my method.
His method looks much easier if your situation will let you use it.

[1950ChevySuburban]

maybe clean up whats left with a Dremel, make the surface of the bolt flat. Center punch it, then use a good quality LEFT HAND drill bit.

[billwillard]

If you have a mig broken studs are easy. Just start welding to the stud and build until you have something to get a pair of vice grips on. Oil or wax while still hot and let cool. Remove stud as though it were never tight.

[29 sedanman]

Let us know if you get it and what method worked for you.

[mailwagonman]

The problem with drilling out broken bolts is that you can't stay in the center. If you do manage to get a hole in it the next thing you will do is break an easy out in the hole. The secret to getting out broken bolts is to heat them as hot as you safely can and then cool them off with water immediately. If you have to weld a washer and a nut do so before you heat. Spray some oil on it and start rocking the bolt back and forth. Never try to just screw it out. Rock it until you can move it further each time. Sometimes a tap with a hammer even helps. The reason this helps is the expansion and contraction you get from the heating a cooling turns the rust and crud aloose. You may have to make several heating attempts or weld new washers and nuts on, but it will work. I have been in the welding business for 27 years and I have gotton out thousands of bolts this way.

[coopdevill65]

the best way is to use a washer and nut to get them out. if its a 3/8 stud use a 3/8 fender washer and line the hole up with the stud or hole where stud is countersunk. fill in the hole or weld the stu to the washer. then line up the nut i use a 3/4 nut so you have a bigger hole and wrech surface and weld in the nut and a couple of spots arond the nut to the washer.COOL IT WITH PENNITRATING OIL! wait till its cool to touch. then heat the area around the stud and SLOWLY use an impact gut to take it out. im a muffler man and i deal with this shit every day! fords are the worst but with patience you will get it. its a fine art everyone in my shop lets me get the stuff they breakout! is a fun challenge.

[llonning]

The best bits I have found for drilling heat hardened bolts/studs are cobalt. I had some broken head bolts in an old Wisconsin V-4 to remove std bits walked even with a split point. Ordered the coblat split points from MSC. Worked like a charm. Now I have a bunch of cobalt bits.




Good luck and good rodding!!!

[SinisterCustom]

Another option.....got a stick welder?
There is special rod made for extracting broken bolts....carefully weld in the hole to the end of broken stud, you can build it up high enough to weld a nut on it. The weld doesn't stick to the internal thread. It's been years since I've seen this done, so I forget the type of rod it is....but it works good, especially for BIG bolts broken below the surface...

[Flatdog]

If you want to drive to denville Nj 1 hour rideI will do the job. PM me.