Help!!! Snapped bolt off in crankshaft!!!

Man am I in for it. I was backing out the bolt to remove the vibration damper. It was extremley hard to turn but was turning. I backed it out maybe two to three full rotations. Then it snapped. I already know it's not looking good. Infact every mechanic I talked to so far told me the cheapest fix is to swap the engine cause your going to need to replace the crankshaft. I see three options. I can either weld a bolt head onto it and try to work it out with oxy acetelyne, but I don't feel good applying that kind of heat to the engine. So I was going to get some good drills and about a week, then try to bore out the center and hope it relieves the stress enough to back it out. Alot of mechanics are telling me that this bolt is so hard it will take a custom made drill to drill through it. Though a machinest told me it can't be that hard, cause it would be too brittle. The third option that I've come up with is bringing it to a machine shop to see if they can extract it. I am hoping this will be a common task for them but have no idea. I imagine they would have precision drills and/or other equipment for doing this task. I am emotionally distraught with my Jeep down. I need help. I figured the only real option I have is to ask other people who work on 35 year old engines. Please, give me some insight. One thing that might be a plus, is the bolt didn't snap flush. There is 1/2" to 3/4" of threaded "stud" sticking out that I can grab with a pipe wrench, though I don't see that helping. Time to drop in a V8? Please help, its breaking me down quick.

 

Start soaking it with a good penetrating oil, not wd-40, use some expensive stuff. Then try to weld a nut to the stud that is sticking out and use that to back the bolt out.

 

I usually use PB Blaster. I've actually had good luck with soaking stuck bolts in penetrating oil, then frying it out with a propane torch then repeating multiple times. Could have just been luck though. Do you think the heat would cause the bearings to seize up,gaskets to go, etc?

 

1st question, are you using arc or wire-feed? If I am thinking straight (Dr's still got me on some good meds!R) ), then the mass of the crank should help dissapate the heat from the weld before messing up your bearings, etc., when you weld a head onto the part left sticking out. (Wire feed is more precise (IMHO) that's why I asked which type of welder.) Chamfer the ends, lay multiple beads to build thickness and let that puppy soak in oil as suggested.
I do agree about not using a torch for this project.
Good Luck

 

An old timer mechanic friend ran into a similar problem several years ago. What he did was turn a blind ended hole in piece of steel in a lathe that would fit precisely over the crank snout like sor of a cap. He left the blind end about 1 inch thick. Then he drilled a center hole in the blind end. He used this as a drill guide to drill a hole dead center into the broken off bolt so he could use a maximum size easy out on the bolt. I guess he didn't trust himself at free hand drilling.

 

these work good,i have one,i dont think it is rusted rather the threads have gaulded,and therefore it is gonna be tough,good machineshop would be your best bet while you still have something to grip onto,however if you decide to try it yourself i would sugest trying to turn it back in a little then work it back and fourth gradually backing it out,lots of PB blaster on this one,i just dont think WD-40 is gonna cut the mustard on this one,careful with heat the crank is cast and cast dont like high temps

 

I have access to all kinds of welders, but I think the welder of choice would be the 240volt mig. Ummm..so you think soaking it for a few days is the best bet even though its coming out of the front of the engine and most of the PB Blaster goes straight to the ground? I will go check out those bolt extractors. I'll let it soak for days then go at it with a pipe wrench, vise grips, or anything that will grab it. If I can't grab it, I'll resort to welding. If the bolt snaps, I'll start drilling. In the mean time, I'm waiting for a call from a few machine shops. Thanks for being there for me in this time of distress.

Do you think putting two flat sides with an angle grinder on the bolt, in order to grab it better with vise grips or a pipe wrench, would be a good idea or bad idea?

 

being a machinist the worst thing you could use is them easy outs. we get alot of people that use them and then bring them to use to get both the easy out and the broke off bolt out. If it was me and I did not have the tools or machines to get the bolt out I would take it straight to a machine shop. do not do anything to it. except squirting a good penetrant on it. the more you screw with it and if you do not get it out the harder it will be for a machinist to get it out.

 

Pm sent!

 

I took this picture today.

 

I liked a previous idea posted last week, somebody said too weld on a nut
then quickly pour on cold water, and they said they could remove it by hand Most of the time, but personally I would try to turn it back in, where it was loose enough before it broke. Then add penetrating oil and continue to work it back and forth like you would if you were cutting new thread's. This would be especially easy, since you have some thread still sticking out in order to screw on a nut. Best wishes, I know the feeling.
Doug/Tucson

 

I'm thinking before I weld it, I will try putting two nuts on, using one as a jam nut. Then I'll work it back and forth with an impact gun, giving it all the time it needs. When it broke, i was using the impact gun working it back and forth with PB Blaster. In the pic above, you can actually see the clean threads, where the bolt did infact back out before it snapped. I thought the gun wasn't powerful enough because it kept stopping and it was 18V. Then the bolt head fell off...damn Snap-On. This time I will give it all the time the Jeep requests.

 

It you have enough threads to get 2 nuts on I would use hand tools, if possible, for starters. I would be afraid to use an impact wrench at this point with my luck. It would snap off flush
Doug/Tucson

 

Thats true, I was thinking more about keeping the crankshaft from spinning...use an impact gun. Tho I suppose I can put it in gear and block the tires for good measure?

 

I wouldn't use an impact on it, no matter what.

 

Blocking the tires won't do it. Jeep will roll enough to mess you up. Put her in gear and either set the e-brake or have somebody step on the brake pedal for you to keep the engine from spinning with the t-case and tranny in gear. Then use hand tools. An impact will be more likely to waste the bolt again. With hand tools you can fell if the bolt is turning or if it's twisting.

I had the same thing happen to both a small block Chevy and a Cadillac 500. I was able to drill both out increasing the bit size until I could clean up the remaining bolt with a tap. Sucks. If it ever happens to me again the engine is getting yanked and sent to the machinist 'cause it's honestly easier pulling the engine than going through all that again. You're actually pretty lucky that you've got so much bolt sticking out to work with.

Good luck, man.

 

That sucker must really be stuck to snap the head off a 1/2" grade 8 bolt like that. I wonder if it's got something like red loctite on it. Maybe heat from propane torch?

 

at least you got something to work withbe glad it didnt snap off flush,or even back up in the crankimpact has pulled a thred up on top of another{gaulded},seized or what other word fits here,thred in the crank are softer since its cast,gonna have to work it back and fourth with PB applied often,try a half a turn in and threequaters a turn out till it comes may take a while,got to work that pulled thred loose,not too much pressure you will force that pulled thred into another and have twice the problem,or break the bolt again or even waste the rest of the threds