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Old 05-06-2006, 01:20 AM   #1
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Alternator bolt...Snap!

A few months ago my alternator bolt on the bottom broke. Thank god it broke enough for me to use some vise grips. Then it snapped again a few weeks later. This time I had to tap it out. Then guess what it snapped again a few days later! This time it snapped fairly far inside. So I tryed to tap it out again and ... Snap! goes the tap inside the dam hole I drilled in the broken bolt!!! So in a hurry I made a make shift bracket so I could run it for a few weeks. Well that turned into a few months. So this weekend I pulled the manifold and drilled a new hole in the tap that was broken and I bought a new set of taps that where supposed to be stronger. Well over the past few months rain got in the hole and caused some rust... So while trying to tap out the bolt, I snapped the new tap inside the old tap hole!!! Now I am up sh!t creek as I cannot find a dam drill bit strong enough to go through the the newest broken tap. Any one recommend a special type of drill bit that will go through the tap?

And why the hell am I breaking these bolts? All pullies line up straight. I don't think I am over torq'n them..?

Any ideas would surely help.

Thanks

Rich
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Old 05-06-2006, 03:13 AM   #2
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Re: Alternator bolt...Snap!

Man, it don't sound good. I really can't think of a easy fix. I would try an end-mill style cutter the correct size to be able to install a keensert thread after. If that size is even available. it seems that something is causing a flex or vibration in the alt. mount that is breaking the bolt. Maybe someone has a better idea?
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Old 05-06-2006, 07:18 AM   #3
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Re: Alternator bolt...Snap!

A picture of your setup, Like the brackets and such would help. Sounds like you are missing the rear support bracket which keeps it from flexing.
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Old 05-06-2006, 04:00 PM   #4
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Re: Alternator bolt...Snap!

I had similair happen, second bolt was a grade 8. ended up drilling out the threads & installing a heli-coil. Im thinking I may have been running the belt to tight.
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Old 05-06-2006, 04:59 PM   #5
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Re: Alternator bolt...Snap!

The bottom bolt connected to the manifold. I have these ½ inch thick spacers that I where between the manifold and the alternator bolt hole. I have it all apart right now and going to do more with it now that I have some time and the space too. But what does this rear support bracket look like??

Rich

Edit: Piss on it. dam 56k crap! I cannot upload the image. If someone wants I will email it to them and they can upload it.
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Old 05-06-2006, 04:59 PM   #6
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Re: Alternator bolt...Snap!

The bottom bolt connected to the manifold. I have these ½ inch thick spacers that where between the manifold and the alternator bolt hole. I have it all apart right now and going to do more with it now that I have some time and the space too. But what does this rear support bracket look like??

Rich

Edit: Piss on it. dam 56k crap! I cannot upload the image. If someone wants I will email it to them and they can upload it.
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Old 05-06-2006, 07:00 PM   #7
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Re: Alternator bolt...Snap!

Man i pity you. I had the same damn thing happen up front when swapping out a water pump. My tap broke off in there too. There is no drill bit on this earth that I could find that would take it out. What I ended up doing was getting a torch and heating up the bolt till it was nice and red, then we just pulled the trigger on the torch and the easy out popped right out.
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Old 05-06-2006, 07:21 PM   #8
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Re: Alternator bolt...Snap!

Just switch manifolds and call it good. If you heat it with a torch you can easily warp it. Oh, what about carbide bits?
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Old 05-06-2006, 10:27 PM   #9
VetteVet
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Re: Alternator bolt...Snap!

I have had some luck with a center punch and a hammer being able to bust the broken tap into small pieces and working them out. If you can hit the tap with the center punch. It may require re-sharpening the punch a few times.
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Old 05-06-2006, 11:09 PM   #10
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Re: Alternator bolt...Snap!

If none of the other options work an expert at welding might be able to get it out. They make welding rods that are specially designed to extract bolts broken off in holes. They work by welding to the tip of the broken bolt inside the hole and building the thing back up the surface where it's welded to a nut. Then you put a wrench on the nut and back it out. One of the special features of the rod is it doesn't weld itself to the inside of the hole.

I wouldn't have believed this was possible except I've seen it with my own two eyes. This happened on a piece of machinery at an asphalt plant when I broke off a grade 8 bolt. It's impossible to drill hardened bolts with ordinary drill bits and that's when the plant welders came to the rescue. I even saved one of the rods just so I could remember what kind they were.
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Old 05-06-2006, 11:35 PM   #11
Robert1970C20rstbukt
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Re: Alternator bolt...Snap!

Old Yeller is right, those welding rods are awesome. If you lived near me I could fix that for you quick.
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Old 05-06-2006, 11:58 PM   #12
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Re: Alternator bolt...Snap!

I did the center punch today and it broke it into enough peices to start drilling out the old bolt. Then my drill stopped working. So with that I say "screw it". I am going to sit on my ass the rest of the weekend and ponder a different manifold or taking it down to be welded out. Thanks for all the replys all Still not sure what the lower brakect looks like? The motor is a 350 from a 71 if that helps any.

Thanks again.
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