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Discussion Starter · #1 ·
ok to start i=off i have never heard of this happening, i took my car to the track last friday, and havent drove it much this week 2-3 times to the store and back, well tonight i went to the staor and i had the car running while i was putting air in the tires, and i got back in the car and i heard something fall so i got out and looked under the car to see my alutnator and tension laying on the ground, the bolts broke off in the block, what could have caused this, i have never even heard of anything like that happening,
 

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What kind of bolts were you using? Was it a stock mount, or aftermarket?
 

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Never heard it of it on a Ford but it happened once to my wifes Chevy Malibu. I started it up and I heard this clunk and I opened the hood and the alternator was laying on the motor.
 

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YES YES this happens. Seen it several times. What happens is the bolts got a little slack in them and things just happened that they got tension on it and they broke. That small amount of slack is what caused them to be able to be broken. Best thing to do is try to get a piece of square metal tubing spot welded onto the ends of the bolts, then you could get them out. An easy out WILL NOT WORK. A screw out WILL NOT WORK. Those bolts actually go into the passenger side head and you might have to pull that head off to get them out without damaging the threads. Are all 3 bolts broken? Or just 2? Usually the biggest one survives and if it did, you can get the March alternator bracket. It uses only the big bolt hole and attaches to the water pump so you wouldn't have to worry about the other two.
 

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Discussion Starter · #5 ·
just the 2 bolts broke, so how can i make sure it dont happen againg, thread lock, thx for all the advise it just seemed wiried to me, and i was ticked off:frustrated:
 

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It happened to me and it ticked me off too. Best thing to do is just make sure all the bolts are tight, that's about all you can do other than getting actual Grade 8 bolts to replace the factory bolts. I know how it is, I couldn't get those broken ends out to save my life or anyone else's and I wasn't tearing down the engine for them either. I got that March bracket and was done with it. It'll eliminate the smog pump though, not sure if that's an issue where you live or not.
 

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Grade 8 bolts are not good in shear installation. They can be brittle. That's why I asked what kind of bolts you used. Accessory brackets are often designed with single shear and side load on the mounting bolts. With a 5, that's OK, they'll take a lot of deformation before breaking. 8's, OTOH, will break before bending. 8's should be used when there's clamping force only, or at the most, double shear.

In Carroll Smith's book, "Nuts, Bolts, Fastners, and Plumbing Handbook", he states, "There is no place on a race car for a grade 8 bolt". I'm not sure I believe that, but there t is.
 
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