Broken crank pully bolt removal

[vrinner]

Crank pully bolt is busted off in the crank.

The only think done recently (very recently) is that I put on a new A/C belt and possibly put too much tension on the pully? Wierd...anyways...

The only thing that I can see is that the bolt is busted off right at the threads. I'm thinking that drilling it out then an easy out but I dont know if there is a better way to do this. I'd really hate to screw this up any more than it already is.

[Horsewidower]

If you can find any reverse direction drill bits they can be a real help. Sometimes Iv'e had a busted bolt come out while drilling for the easy-out. An industrial supply store should have them.

If Mike's conjecture is correct, that it wasn't tight to begin with, they should make it a relatively easy job.

[vrinner]

If you can find any reverse direction drill bits they can be a real help. Sometimes Iv'e had a busted bolt come out while drilling for the easy-out. An industrial supply store should have them.

If Mike's conjecture is correct, that it wasn't tight to begin with, they should make it a relatively easy job.

Lets hope Mike was right and it will be easy.

So by "reverse direction drill bits" your just saying a drill bit that drills "forward" by drilling in reverse...correct?

[Horsewidower]

Correct.

[Pat_in_L.A.]

^^^ What he said about left hand drills. It may uncrew itself! Stay centered when drilling. Keep the beer cold.

[Dangerranger01]

Left hand drill bits have helped a lot, but then i upgraded to a welder. I'd just weld a but onto the threads, and then use an impact or big breaker bar.

[vrinner]

What size tap do I need to clean out the threads?

[Pat_in_L.A.]

Tell us how it came out and we'll tell you if you need a tap.

[vrinner]

Well, still in the process of getting it out. Actually, not event totally out yets. Completly screwed up. I was able to get a good size extractor into it and it rotated out about 2 1/2 turns then got stuck. It got really stuck. So then I drilled out for the next largest size (size just above 1/4") and it still wouldn't budge. Tried to reverse it back in and we couldn't get it to budge either. We are now at the point of trying to crack the bolt and have obviously screwed up the threads a bit.

So in answer to your question, it's coming out horribly. Dont know if these things can be tapped to a larger size bolt or not, especially while still in the car.

[Horsewidower]

Heat and a paraffin candle?

[vrinner]

I can see a couple of threads showing. Thats about it.

Sounds like removal of the cam and sending it a shop may be in order.

[Pat_in_L.A.]

Sounds like removal of the cam and sending it a shop may be in order.

Cam or crank?

I think that you meant crank.

If crank, there are a few more drill sizes to play with.

[vrinner]

Cam or crank?

I think that you meant crank.

If crank, there are a few more drill sizes to play with.

Crank...sorry...it's been a long night.

5/16 was the last drill bit size that I used and a #5 extractor. My hole was not "perfectly" centered but was pretty darn close.

[jaidedeye]

Im an Aircraft mechanic in the Air Force and i deal with stuck/broken bolts all the time....we use reverse rotation drill bits, easy outs and heat...usually if you heat it up a decent amount that helps alot...u usually drill a fairly deep hole in the bolt and drive the easy out in there as far as i can.

[jaidedeye]

Be very careful with heat. Don't get the actual crank snout hotter than say 500 F and heat it up slowly.

very true...forgot to mention that