Replacing control arm bolts
#1
Replacing control arm bolts
Is it a good idea to replace your front control arm bolts when upgrading to poly bushings? I was thinking that since they work a little differently than the stock rubber ones they might do better with just plain grade 10.9 bolts rather than the reduced shaft bolts that were used originally. Also, it's nice to have new bolts on such critical parts rather than old, rusty 35 year old ones. I'm thinking the reduced diameter bolt design is designed to provide a more even torque potential.
#2
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Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: Replacing control arm bolts
Not really.
The bolt clamps down on the sleeve, which is then held captive and immobile in the brackets. As long as the bushing sleeve fits tight on the bolt, there is no difference.
Now if your particular poly bushings have a larger ID sleeve, then...
None of that has anything to do with 10.9.Or old rusty. (beyond the obvious of course) If it fits, it works.
Never heard of "more even torque potential". Sounds like marketing mouth diarrhea to me.
The bolt clamps down on the sleeve, which is then held captive and immobile in the brackets. As long as the bushing sleeve fits tight on the bolt, there is no difference.
Now if your particular poly bushings have a larger ID sleeve, then...
None of that has anything to do with 10.9.Or old rusty. (beyond the obvious of course) If it fits, it works.
Never heard of "more even torque potential". Sounds like marketing mouth diarrhea to me.
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#3
Re: Replacing control arm bolts
Here's something I found that explains what I was trying to describe about why bolt shanks are reduced when they are in tension: https://www.nord-lock.com/insights/b...f-bolt-shanks/ . Manufacturers used these kind of bolts for a reason.
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Re: Replacing control arm bolts
That's about bolts, not cap screws. Look alot the same but are not.
#5
Re: Replacing control arm bolts
Zero issues replacing a-arm bolts.
stock bolts are all rusted and probably full of oxygen embrittlement.
I used fancy Zinc coated flange head bolts from BellMetric on my 92.
A-Arm bolts:2x:m12x1.75-110mm2x:m12x1.75-90mm
I got away with using 2x 100mm bolts with flange head lock nuts. But they were almost too short. I have maybe 1 thread past the nylon part of the nut
Unrelated pic of my old a-arm powder coated from leftover powder.
.
stock bolts are all rusted and probably full of oxygen embrittlement.
I used fancy Zinc coated flange head bolts from BellMetric on my 92.
A-Arm bolts:2x:m12x1.75-110mm2x:m12x1.75-90mm
I got away with using 2x 100mm bolts with flange head lock nuts. But they were almost too short. I have maybe 1 thread past the nylon part of the nut
Unrelated pic of my old a-arm powder coated from leftover powder.
.
#7
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Car: 1991 BandittII Firebird
Engine: 5.7 HSR
Transmission: 700R4
Axle/Gears: 3.27 9 bolt
Re: Replacing control arm bolts
Zero issues replacing a-arm bolts.
stock bolts are all rusted and probably full of oxygen embrittlement.
I used fancy Zinc coated flange head bolts from BellMetric on my 92.
A-Arm bolts:2x:m12x1.75-110mm2x:m12x1.75-90mm
I got away with using 2x 100mm bolts with flange head lock nuts. But they were almost too short. I have maybe 1 thread past the nylon part of the nut
Unrelated pic of my old a-arm powder coated from leftover powder.
.
stock bolts are all rusted and probably full of oxygen embrittlement.
I used fancy Zinc coated flange head bolts from BellMetric on my 92.
A-Arm bolts:2x:m12x1.75-110mm2x:m12x1.75-90mm
I got away with using 2x 100mm bolts with flange head lock nuts. But they were almost too short. I have maybe 1 thread past the nylon part of the nut
Unrelated pic of my old a-arm powder coated from leftover powder.
.
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#8
Re: Replacing control arm bolts
One of our customers is a third party inspector for the Nuclear industry, their standard regarding Nylocs was the end of the bolt had to be at least flush with the nylon portion of the nut, it could not be below flush with the nylon portion. The way I see it if the Nuclear power industry is good with it, so am I.
#9
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Car: 1991 BandittII Firebird
Engine: 5.7 HSR
Transmission: 700R4
Axle/Gears: 3.27 9 bolt
Re: Replacing control arm bolts
Isn't the rule of thumb you're supposed to have at least two threads showing past the end of the nut when fully tightened? I'm not a big fan of nyloc nuts unless I'm using them on something that had them on to begin with. To me the all metal top lock nuts seem much more substantial and impossible to come loose over time.
Not saying that a nylon nut can't fail, because there's always the potential for and mass produced fastener to fail but in the 20+ years of using nylocs in the power distribution industry I've never witnessed first hand of a nyloc nut failing, maybe I'm just lucky that way
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