Rear axle u-bolts - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Doghouse · 06-19-2007, 02:28 PM

I'm removing the rear lift blocks from my 71' Jimmy. Looking at some of the pictures on the board, I've noticed the u-bolts mounted nuts down and some are mounted nuts up? Also the u-bolts are mounted front to back on the front axle, beside the leaf springs, and side to side on the back axle, stradlling the leaf springs? Can anyone clear this up for me? Thanks, Bob.

hgs_notes · 06-19-2007, 10:45 PM

Yeah, I just replaced mine. The front axle has completely different mounting. The rears are supposed to be nuts down, through a backing plate. GM changed this in 73 I think. Depending on the style of backing plates used on yours, is how you would mount it. If the lift used the newer style backing plate, then you can use them with the correct bolts. The originals were square bent, newer are U bent. Just bring the current bolts to the parts store so they can measure them for what you need. BTW, I went to NAPA and they wanted $15 for each U bolt. I later went to an Auto Value store and got a complete set for $20.

Hope this helps.

florida4x4 · 06-19-2007, 10:54 PM

If you're going to do ANY offroad then you want the U bolts with the plate above the springs. Imagine dragging the threads over obsticles on the square bolt / thread down design. R.I.P.

hgs_notes · 06-20-2007, 12:51 AM

Quote:

Originally Posted by florida4x4

If you're going to do ANY offroad then you want the U bolts with the plate above the springs. Imagine dragging the threads over obsticles on the square bolt / thread down design. R.I.P.

Good point. I will probably be switching mine once I actually start using it. I needed bolts at the time because they were cut and I needed to move it out of the junkyard. I'll probably do a lift of some sort and switch them then.

If he wants it back to original though, I wanted him to know which way was correct.

Doghouse · 06-20-2007, 01:26 PM

Thanks guys. Went to the local tire/spring shop yesterday afternoon with the backing plate and lifted u-bolt. He confirmed what you said. The plate sits on top (nuts up). The u-bolt was a square type, mounted nuts up, so the PO had them mounted upside down. The spring guy set me up with some shorter rouned ones. Thanks again, Bob.

06-19-2007, 02:28 PM	#1
Doghouse Registered User Join Date: Apr 2007 Location: Wyoming, Ontario. Posts: 10	Rear axle u-bolts I'm removing the rear lift blocks from my 71' Jimmy. Looking at some of the pictures on the board, I've noticed the u-bolts mounted nuts down and some are mounted nuts up? Also the u-bolts are mounted front to back on the front axle, beside the leaf springs, and side to side on the back axle, stradlling the leaf springs? Can anyone clear this up for me? Thanks, Bob.

06-19-2007, 10:45 PM	#2
hgs_notes GEARHEAD Join Date: Aug 2003 Location: MN Posts: 6,126	Re: Rear axle u-bolts Yeah, I just replaced mine. The front axle has completely different mounting. The rears are supposed to be nuts down, through a backing plate. GM changed this in 73 I think. Depending on the style of backing plates used on yours, is how you would mount it. If the lift used the newer style backing plate, then you can use them with the correct bolts. The originals were square bent, newer are U bent. Just bring the current bolts to the parts store so they can measure them for what you need. BTW, I went to NAPA and they wanted $15 for each U bolt. I later went to an Auto Value store and got a complete set for $20. Hope this helps. __________________ If no one knows what you're doing, they can't tell you you're doing it wrong HG's Dream Car Build - Shelby Cobra Kit Build your own adjustable track bar 71 Long Fleet C/10 72 Jimmy 4x4 (Junkyard Jimmy) HG's Plow Truck '78 K35 Dually Bigass Farm Truck HG's thread of miscellaneous stuff

06-19-2007, 10:54 PM	#3
florida4x4 Registered User Join Date: Dec 2002 Location: tally FL Posts: 74	Re: Rear axle u-bolts If you're going to do ANY offroad then you want the U bolts with the plate above the springs. Imagine dragging the threads over obsticles on the square bolt / thread down design. R.I.P. __________________ 1972 GMC Jimmy - 383SBC \| TH350-NP203-NP205 \| D60PL \| 14FF Detroit \| 42 TSL's \| 4Xeyes \| Heavy FOotE "Trail in. Trash out." Florida4x4 dot Com

06-20-2007, 01:26 PM	#5
Doghouse Registered User Join Date: Apr 2007 Location: Wyoming, Ontario. Posts: 10	Re: Rear axle u-bolts Thanks guys. Went to the local tire/spring shop yesterday afternoon with the backing plate and lifted u-bolt. He confirmed what you said. The plate sits on top (nuts up). The u-bolt was a square type, mounted nuts up, so the PO had them mounted upside down. The spring guy set me up with some shorter rouned ones. Thanks again, Bob.



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