legacycentral bbs

My crank pulley bolt snapped off inside of the crank.

Am i screwed? or is there a way to fix this without having to get a new engine.

Drill a hole and reverse tap it so you can lock a bolt in it and hopefully get it out. A little bit of heat to the end of the crank might help. Don't make it cherry or anything as that will change the crystalline structure of the metal.


Drilling the hole won't be easy. It is forged steel.

before you start heating or drilling you should try tapping it around with a small punch or chisel. Once the head has come off there might be no load on the threads and it might turn easily. I wouldn't advise heating it at all myself, that will make it tighter in the hole not looser... unless you heat the crank, which would require a lot of heat and wouldn't be a good idea.

^ Ok thanks ill try that today

I didn't mean roast the hell out of the crank, just warm it up a bit so it expands a bit and lets go of the bolt a little. You aren't going to do anything to the metal short of 4-500 degrees.

the bolt is gonna expand to heating it wont do a god damn thing . i would drill out it and retap the hole . that is gonna be your best bet

Use good penetrating oil and let sit. Try to get an easy-out on it while tapping the end of the crank rapidly and lightly with a ball peen hammer or such as logic1call suggested.

chiplrx-sli wrote:the bolt is gonna expand to heating it wont do a god damn thing . i would drill out it and retap the hole . that is gonna be your best bet

IF you sit there with a torch for ten minutes, then yes. If you are fast with it then then crank heats first, and relives stress on the bolt.



This is only necessary when one is having trouble with an easy out anyways.

If only i had time to do this. Im thinking its time for a new engine build.

take bolt out = a few hours
rebuild engine and replace engine = weeks

you dont have time to get the broken bolt out but you have time to replace the whole motor?

http://www.youtube.com/watch?v=WL1lfSzgcAw

Im leaving for school tomorrow. I fiqure i should just start sourcing parts for a motor build when im back in school.

^^
lol

a small amount of heat will help

think about cracking a nut in the winter compared to the summer

chiplrx-sli wrote:the bolt is gonna expand to heating it wont do a god damn thing . i would drill out it and retap the hole . that is gonna be your best bet

Wrong because heating it up expands both the bolt/crank slightly so it breaks the seal that has built up over time and in turn makes it easier to unthread the bolt from the crank. I had to do this with every stud on my turbo so i could replace them.

Always use heat as a last resort, but a little might help it out. No matter what you do, though, you've got to be able to get a good bite on what's left of the bolt.

It really depends on the circumstances. If the bolt broke off by being over-tightened, or while being tightened due to a faut in the bolt, then it often happens that the load has come off the threads and they will turn out with very little effort... perhaps even the fingers. If the bolt was too long and bottomed out, (because there was no pulley on there for instance and the bolt was being used to turn the motor), or, if the bolt was just rusted in there with old age, then it will be tight still and will need more work to get it out. There is no point rushing in and drilling or heating if that isn't nessecary. First try turning it with a small punch. If that doesn't work then drill it and use a ezyout of the proper size. If the correct size ezyout doesn't get it to move then try a little heat applied quickly to the crank and not the bolt, which means get a big tip or a gas axe and apply a lot of heat briefly. If a little bit of heat doesn't do it then drill it right out to a thin shell and either unwind the shell or retap it. Often if you drill them right out till there is only a thin shell left then they loosen and come out easily.... this does require accurate centering of the drill of course, which can be difficult with a crookedly broken bolt. Always try the easiest, least likely to do more damage option first.

Ok im goint to try that. How do you remove the front bumper.

And by the way i think the bolt was over tightened because it broke as i was driving the car.

get a small pin punch and grind it into a tiny cold chisel. Dont make the angle too sharp. Get a small hammer and use the chisel to tap a little on the top side of the broken bolt in a leftwards direction, then give it a few taps at the bottom in a rightwards direction. Keep doing that for a few minutes and see if it moves at all. If it moves at all then you are going to get it, just keep moving around hitting it in different places so you don't end up chiseling away the steel too much.

First off, did you break the bolt trying to loosen it or trying to tighten it?

In the case of the latter, then I agree with log1call. The bolt probably didn't break cleanly, so there's a ridge or pit or some other imperfection in the bolt remnant that will likely allow you to grab ahold of it so to speak and slowly twist it out.

Like log1call said, now that the head's broken off, there's virtually no torque on the bolt remnant, so you don't need much force to get it out.

I've broken several bolts off in various places, and I've always managed to use a pick against an imperfection in the bolt remnant to slowly unscrew it.

Indeed, spray it plenty with penetrating oil and let it sit for a day or two. You should be able to get it out without drilling or other extreme tactics.

DerFahrer wrote:First off, did you break the bolt trying to loosen it or trying to tighten it?

In the case of the latter, then I agree with log1call. The bolt probably didn't break cleanly, so there's a ridge or pit or some other imperfection in the bolt remnant that will likely allow you to grab ahold of it so to speak and slowly twist it out.

Like log1call said, now that the head's broken off, there's virtually no torque on the bolt remnant, so you don't need much force to get it out.

I've broken several bolts off in various places, and I've always managed to use a pick against an imperfection in the bolt remnant to slowly unscrew it.

Indeed, spray it plenty with penetrating oil and let it sit for a day or two. You should be able to get it out without drilling or other extreme tactics.

The bolt broke as i was driving the car. I would think that it was because i over tightened it.

I wont be able to try anything until march because i am away at school now.

Thanks for the help.