Lower Control Arm U-Bolts - The 1947 - Present Chevrolet & GMC Truck Message Board Network

MStokes · 09-08-2003, 10:35 AM

Are the 4 U-bolts that hold the front lower control arm shafts to the frame supposed to be the same size? I noticed I have two that are slightly larger than the other two. If two are supposed to be a little larger, where do the larger ones go?

**1971Stepside** · 09-08-2003, 10:50 AM

Mine were all the same size.

**Classic Heartbeat** · 09-08-2003, 11:16 AM

Sounds like someone only replaced U-bolts that were bad at one point. Some of the origanals were the smaller ones, however they would have all been that way. The larger ones were produced to replace the smaller ones, and all that are available now. You probably have two different size holes in your crossmember also, so if you want to reuse the U-bolts then the larger ones will not fit in the smaller holes. If they do then it realy doesn't matter where they go. I wouldn't re-use them myself, the nuts are self locking and may not work as well the second time around. WES www.ClassicHeartbeat.com

MStokes · 09-08-2003, 11:20 AM

Thanks for the details Wes. Should I be able to get suitable replacements with self locking nuts at a bolt supply house or would I need to special order them from a part vendor?

71HUGGER396 · 09-08-2003, 11:48 AM

I just bought these parts at napa, the new bolts were 9/16". I thought I would have to drill the holes out but they just fit.

MStokes · 09-08-2003, 11:51 AM

Should these U-bolts be grade 8?

Hugger · 09-08-2003, 12:04 PM

I just re-did my front end this past weekend...
In the picture you posted one has flat washers, and the other has lock washers.
I replaced my self locking nuts with grade 8 nuts, and lock washers.
Anybody se a problem with using lock washers, instead on self-locking nuts?

Fred T · 09-08-2003, 02:54 PM

Quote:

Anybody se a problem with using lock washers, instead on self-locking nuts?

They take a lot of vibration and can work loose. Use red Loctite.

I purchased 1/2" grade 8 flanged locknuts with black oxide coating at the hardware store, they were over a buck each!

09-08-2003, 10:35 AM	#1
MStokes Registered User Join Date: Aug 2002 Location: Meridian, Idaho Posts: 164	Lower Control Arm U-Bolts Are the 4 U-bolts that hold the front lower control arm shafts to the frame supposed to be the same size? I noticed I have two that are slightly larger than the other two. If two are supposed to be a little larger, where do the larger ones go? Attached Images __________________ 1972 C-10 LWB, 400/350, 2WD 1972 C-20 Custom Camper, 350/350, 4WD (Converted)

09-08-2003, 10:50 AM	#2
1971Stepside Almost Satisfied Join Date: Mar 2002 Location: Springfield, MO Posts: 2,932	Mine were all the same size. __________________ 1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3200 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Finally back on the road in 2021. "I can't complain, but sometimes I still do. Life's been good to me so far."

09-08-2003, 11:16 AM	#3
Classic Heartbeat Project Junkie! Fishing Poor!! Join Date: Dec 1999 Location: Olympia,Wa. 98512 Posts: 10,766	Sounds like someone only replaced U-bolts that were bad at one point. Some of the origanals were the smaller ones, however they would have all been that way. The larger ones were produced to replace the smaller ones, and all that are available now. You probably have two different size holes in your crossmember also, so if you want to reuse the U-bolts then the larger ones will not fit in the smaller holes. If they do then it realy doesn't matter where they go. I wouldn't re-use them myself, the nuts are self locking and may not work as well the second time around. WES www.ClassicHeartbeat.com __________________ On-line catolog Classic Heartbeat Pickup Parts WEHEPP@comcast.net Call us Toll Free (888) 338-2502 Like Us on Facebook No appointment necessary. 72 BB Chevy Custom Deluxe / Custom Camper 67 I-6 (Soon to be 5.7 LS1) Panel 68 BB Chevy Short Bed 72 6.0 LQ9 Short Bed Chevy 4X4 Olympia's fastest growing truck parts supplier. Olympia's home for Wayward Chevys

09-08-2003, 11:20 AM	#4
MStokes Registered User Join Date: Aug 2002 Location: Meridian, Idaho Posts: 164	Thanks for the details Wes. Should I be able to get suitable replacements with self locking nuts at a bolt supply house or would I need to special order them from a part vendor? __________________ 1972 C-10 LWB, 400/350, 2WD 1972 C-20 Custom Camper, 350/350, 4WD (Converted)

09-08-2003, 11:51 AM	#6
MStokes Registered User Join Date: Aug 2002 Location: Meridian, Idaho Posts: 164	Should these U-bolts be grade 8? __________________ 1972 C-10 LWB, 400/350, 2WD 1972 C-20 Custom Camper, 350/350, 4WD (Converted)

09-08-2003, 11:48 AM	#5
71HUGGER396 Confirmed Truckaholic Join Date: Oct 2000 Location: Sarver,PA 16055 Posts: 732	I just bought these parts at napa, the new bolts were 9/16". I thought I would have to drill the holes out but they just fit.

09-08-2003, 12:04 PM	#7
Hugger Registered User Join Date: Mar 2003 Location: Wichita, KS Posts: 137	I just re-did my front end this past weekend... In the picture you posted one has flat washers, and the other has lock washers. I replaced my self locking nuts with grade 8 nuts, and lock washers. Anybody se a problem with using lock washers, instead on self-locking nuts? __________________ 72 LWB - Hugger Orange 350/350 3.73 Next; 335hp GM Crate

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