Bolt strength

[Bill Cleveland]

I have a problem shearing one of the bolts in my low-mount alternator bracket. It's happened twice. First time the custom chrome socket head bolt that came with the kit broke in the block; EZ Out got it out and replaced with a regular grade 8 bolt. Now it has failed again, but fortunately left enough thread that I could grab it with vice grips & extract it. There is a bushing in the bracket that should help with the shear loads, but I have to keep the belt quite tight since it squeals if there is any slack at all. Any suggestions? Would stainless offer more shear strength?

[Kevin Seward]

Hey Spanky, I have had similar problems with mine also, think I broke 3 or 4 bolts over the years. I finally put a straight edge on all 3 pulleys and shimmed carefully for as close to perfect alignment as possible and knock wood, so far the bold has held up very well ever since.

Hitec

[Bill Cleveland]

OK, here's what I have done: upgraded the stressed bolts to Grade 9 from McMaster-Carr, and added a steel strap between the alternator pivot bolt and a bolt holding my fuel pump block-off plate. This seems to have stabilized it a good bit. We'll see . . .
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Alt bracket.jpg (48.49 KiB) Viewed 213 times

[Rolla Hessel]

Spanky if you need a stronger bolt, give me a call. The ones I have here are 38% stronger than Grade 8 but if you are having Shear issues, it’s not the bolt that’s the problem.. You definitely don’t want to use Stainless!!! Only equivalent to grade 2.