# rear control arms-tubular/boxed and adjustable/not



## russosborne (Dec 6, 2010)

Looking at Summit Racing, and getting some ideas for the 70 Lemans. Was wondering what the general consenus is on the rear control arms. I won't be racing this car at all, but want it to handle well and not have to worry about anything breaking. Figure I will have to replace these at some point, so might as well upgrade, just dont' want more than I need. 
Thanks,
Russ


----------



## Eric Animal (Oct 28, 2007)

Boxed lowers, adjustable uppers. Sweet and simple!:cheers


----------



## dimitri (Feb 13, 2009)

I removed my rear control arms, boxed welded them, replaced all of the rubber bushing with new rubber bushings. I also put a 7/8" sway bar. New KYB shocks and new heavy duty springs. The car handles great. Never go larger than 7/8" with stock rims. Front sway bar you can go as big as 1.25".


----------



## BearGFR (Aug 25, 2008)

Eric Animal said:


> Boxed lowers, adjustable uppers. Sweet and simple!:cheers


X2 - This is the easiest solution. On the uppers, spend a little extra and get adjustables that also have some sort of spherical/fully articulated joint at the chassis end. This allows the rear axle to have much more freedom of movement, especially in turns or other "body roll" situations. The triangulated geometry causes the factory uppers to bind and forces deflection in the rubber bushings. Using hard polyurethane bushings in the factory arms only makes the binding problem worse. Adjustable uppers also allow you to correctly set your driveshaft operating angle / pinion angle.

For the same reason, factory lowers also bind during body roll and force bushing deflection, and actually twist the arms a little. It's not as bad as on the uppers though, so using boxed lowers with urethane bushings is a good idea. If you've got the budget, fully articulated lowers that allow the arm to twist freely without binding are "better", but you may never see the difference unless you're big time into carving corners. One more slight advantage in having adjustable lowers is that they permit doing "4 wheel" suspension alignments to make sure all 4 wheels are tracking perfectly in line with each other. 

Bear


----------



## russosborne (Dec 6, 2010)

Thanks for the info.
I happened across these 64-72 CHEVELLE ADJUSTBLE UPPER CONTROL ARMS while cruising craigslist. I just reread about the articulated ends, and I don't think these have them, but other than that do they sound ok if on a budget?
The company is essentially local, which means no shipping. 
Thanks,
Russ


----------



## BearGFR (Aug 25, 2008)

russosborne said:


> Thanks for the info.
> I happened across these 64-72 CHEVELLE ADJUSTBLE UPPER CONTROL ARMS while cruising craigslist. I just reread about the articulated ends, and I don't think these have them, but other than that do they sound ok if on a budget?
> The company is essentially local, which means no shipping.
> Thanks,
> Russ




I can't tell for sure from the photos, but if the bushing ends are free to swivel with the adjusters tight then these might even allow good articulation. I'd ask. They look pretty good.
Bear


----------



## Eric Animal (Oct 28, 2007)

here are a few pics of a 4 link system with articulated ends. You only need the "ball in socket" joint on one end. Street Rod Garage Made these for me. Eric


----------



## geeteeohguy (Feb 2, 2008)

I just re-bushed all my rear control arms when I did a rear diff swap recently on the '67. the car had always had a thrust angle issue (since I bought it in '83), but it had gotten worse over time. I found when I yanked the diff, that one of the upper arms was twisted and the bushings were off center. I replaced the arm with a straight one, and installed the Moog rubber bushings. No more pulling to the right when going down the road! There was no way to see how bad the arm and bushings were with the rear diff installed in the car. Only when I removed the arm was I able to see what was going on. Those stock arms are remarkably thin and cheesy, and it's amazing they work and last as well as they do. I would think that an upgrade to the adjustable arms as mentioned above would be an excellent improvement.


----------



## BearGFR (Aug 25, 2008)

Eric Animal said:


> here are a few pics of a 4 link system with articulated ends. You only need the "ball in socket" joint on one end. Street Rod Garage Made these for me. Eric


Man Eric, my mouth waters every time I see photos of your project...

Bear


----------



## Eric Animal (Oct 28, 2007)

Thanks Bear! I can't wait to start "putting her together". I am waiting on a Wilwood Brake Kit (next week). Then I can put wheels on. Then off to the body shop for fitment......Then engine/tranny mock up....Then complete disassembly of chassis, and off to the powder coating shop.....Then......arty:


----------



## BearGFR (Aug 25, 2008)

Eric Animal said:


> Thanks Bear! I can't wait to start "putting her together". I am waiting on a Wilwood Brake Kit (next week).


Wilwood "kit".... ::shudder::  ---- I put Wilwood "kits" on both ends of my GTO too, in fact I just finished buttoning up the complete hydraulic system yesterday. The "kits" lacked some significant pieces that were required to actually install and hook everything up. Little things like inverted flare fittings, flex lines, hub "protectors", parking brake cables....

Their instructions said to safety-wire "everything" too, so if you don't have a set of safety wire pliers.... I got some from Eastwood.

Bear


----------



## Eric Animal (Oct 28, 2007)

Bear, I got all the lines from SRG....I think I will be OK. I am not sure about the parking brake issue. I will probably have some fabing to do there as the chassis is not stock either:confused....such is the nature of the hobby! i will post when the kit arrives and things start happening. Eric


----------



## BearGFR (Aug 25, 2008)

Eric Animal said:


> Bear, I got all the lines from SRG....I think I will be OK. I am not sure about the parking brake issue. I will probably have some fabing to do there as the chassis is not stock either:confused....such is the nature of the hobby! i will post when the kit arrives and things start happening. Eric


The Lokar parking brake cable kit I got is actually a "universal" kit. It has the correct hardware to connect to the Wilwood brake actuators, but the rest of it is a "cut to correct length and assemble" proposition, so perhaps it would work for your setup too.

Bear


----------



## Eric Animal (Oct 28, 2007)

Bear,Thanks for the info! Eric


----------

