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U-bolt torque

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Old Nov 24, 2015 | 04:28 PM
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Default U-bolt torque

Can these things be on too tight? I've read a lot of varying numbers for the proper torque.
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Old Nov 24, 2015 | 06:20 PM
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Originally Posted by jg22
Can these things be on too tight? I've read a lot of varying numbers for the proper torque.
Kinda vague link....
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Old Nov 24, 2015 | 06:47 PM
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Originally Posted by cruiser54
Kinda vague link....
I've seen as low as 40, some say 100+, some say as tight as possible, some say depends on the ubolts. I'm getting all this info from using the search function.
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Old Nov 24, 2015 | 06:58 PM
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Leaf spring u bolts?

55 pounds for 1/2" bolts and 100 for 9/16" bolts. from the factory service manual.
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Old Nov 24, 2015 | 07:19 PM
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well consider this, when i went from 1/2 to 9/16 on my 8.25 i thought well 100 ibs is right for 9/16. so i tighten to that. drove around a few days & noticed my drivers side was sitting lower then the pass. side in the rear, measure it & its a 1/4 " difference. it was always dead even before the u bolt change, so i crawl under & start looking. the u bolts had crushed into the housing tube on that side by a 1/4 ". to get it level i had to loosen all 4 u bolts , put a 1/4 " shim on the drivers side perch. then i retightened all 4 to 65 lbs. been fine ever since. i have never seen anything like this before, so looks like you can go too tight at least for the housing tube that is. wierd thing is it only dented in on the one side ?
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Old Nov 24, 2015 | 08:05 PM
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Appreciate the responses. The reason I ask is because on my 8.8 swap I torqued to 100 (they are 9/16). The tops of the u bolts that would get cut off are now not completely straight up and down after torqueing the bolts.
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Old Nov 24, 2015 | 08:49 PM
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The BOLT specifies the torque....>>NOT the FSM.

The 9/16 grade 8 bolts that I used called for 75lbs.

Yes, you will crush the tube.
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Old Nov 25, 2015 | 03:53 PM
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So I called ECGS today to find out the torque specs. They said torque to 105....
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Old Nov 25, 2015 | 04:18 PM
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Originally Posted by Jeep Driver
The BOLT specifies the torque....>>NOT the FSM.

The 9/16 grade 8 bolts that I used called for 75lbs.

Yes, you will crush the tube.
Huh? The FSM differentiated the torques according to U-bolt size......
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Old Nov 25, 2015 | 06:34 PM
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Originally Posted by cruiser54
Huh? The FSM differentiated the torques according to U-bolt size......
What grade 9/18 ubolt came from the factory?

You want to bet it was a grade 5?

Will a 5 stretch more than a 8?
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Old Nov 25, 2015 | 06:36 PM
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Originally Posted by Jeep Driver
What grade 9/18 ubolt came from the factory?

You want to bet it was a grade 5?

Will a 5 stretch more than a 8?
Who knows?

I've never put a torque wrench on a ubolt in my life and I've (gasp!) re-used ubolts.
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Old Nov 26, 2015 | 11:34 PM
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I didn't know a u bolt had a torque to number and i have reused them also.
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Old Nov 27, 2015 | 06:31 AM
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Originally Posted by andrewmp6
I didn't know a u bolt had a torque to number and i have reused them also.
we're doomed andrew.
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Old Nov 28, 2015 | 06:12 AM
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I have reused head bolts because i was stuck in a pinch and the motor still runs fine.Or a driveway alignment with a long enough piece of string or rope a few times.But i have always owned old junk you can get away with a lot more then a modern car.
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