Making my own suspension arms

[The Stickman]

Ok my car is a 1984 Oldsmobile Custom Cruiser wagon. There are many parts for these cars and I have a wife that is a welder so I figure why not make them. It has the for suspension arms on the rear end.. They are pretty simple in design so shouldn't be too hard to do. I will be using box tubing with round tubing for where the bushings go. My question is how thick should the wall thickness be for the box tubing. Also what are the advantages to adjustable upper arms?

[bbcc]

Just some constructive criticism, don't do it. I was all gung ho about making some wicked control arms for a custom camber curve, my own track width, different spindles for easy big brakes, and so on. When you look into it, it's really not worth it. At least for me it wasn't. The amount of time doing research, stress analysis, modeling, jig creation, material sourcing, welding, and post machining, my god those are mulit thousand dollar control arms! I'm an engineering student, so I'm expected to do some questionable things on my free time, but holy smokes! Sourcing control arms isn't to bad. I'm willing to bet you share the same suspension parts as something more mainstream that you can adapt to your car.

Not trying to kill a dream bud, just trying to save you a little bit of time and money.

Cheers, Ryer.

[oestek]

Maybe just box your rears.. save some time and materials like Ryer said, but still make an improvement. Here's some we did:

http://v8tvshow.com/content/view/632/43/

[The Stickman]

Just some constructive criticism, don't do it. I was all gung ho about making some wicked control arms for a custom camber curve, my own track width, different spindles for easy big brakes, and so on. When you look into it, it's really not worth it. At least for me it wasn't. The amount of time doing research, stress analysis, modeling, jig creation, material sourcing, welding, and post machining, my god those are mulit thousand dollar control arms! I'm an engineering student, so I'm expected to do some questionable things on my free time, but holy smokes! Sourcing control arms isn't to bad. I'm willing to bet you share the same suspension parts as something more mainstream that you can adapt to your car.

Not trying to kill a dream bud, just trying to save you a little bit of time and money.

Cheers, Ryer.

Well I don't plan on changing any geometry. I just plan on making a jig from the stock rear arms much like what oestek posted. I had considered boxing them but thought an all new piece would be better. Esspecially as i need to make a custom swaybar mount. You see the B-Body wagons are wider than regular Bodies sedans. So the suspension arms are further apart and the swaybar is slightly wider. So here I could kill 2 birds with one stone.

[bbcc]

Oh man, I appologize. When I first read your initial post I thought you were doing the rear aswell as the fronts. Ya, the rears are quite a bit easier than the front control arms. Kevin thats a great how-to for stiffening up your stockers. If you want to do the tubular thing, remove your old control arms. Lay it on a welding bench, put a couple bolts through the bushings and weld the bolts to the table. This will give you your length. Some C.R.S. 1020 tubing, around .1-.15 wall should be enough for the rears. Depends on what you have available. Maybe check with some other people for what they have used. You should be out and rocking within a day or two.

Again, sorry for coming off so rough. I really gotta work on slowing down when I read.

Cheers, Ryer

[Twentyover]

May want to consider something like Johhny Joints rather than bushings on the arms to permit articulation non-parallel to the bolts. And remember the upper and lower arms travel in arcs- you dont want uppers too stiff or they'll try to bind the suspension

[The Stickman]

Oh man, I appologize. When I first read your initial post I thought you were doing the rear aswell as the fronts. Ya, the rears are quite a bit easier than the front control arms. Kevin thats a great how-to for stiffening up your stockers. If you want to do the tubular thing, remove your old control arms. Lay it on a welding bench, put a couple bolts through the bushings and weld the bolts to the table. This will give you your length. Some C.R.S. 1020 tubing, around .1-.15 wall should be enough for the rears. Depends on what you have available. Maybe check with some other people for what they have used. You should be out and rocking within a day or two.

Again, sorry for coming off so rough. I really gotta work on slowing down when I read.

Cheers, Ryer

No problem. I was planing on doing it the way you said. I just wasn't sure of things like wall thickness. I also know some aftermarket bars for other cars the uppers are adjustable length and wasn't sure of what that did for performance or why.

[The Stickman]

May want to consider something like Johhny Joints rather than bushings on the arms to permit articulation non-parallel to the bolts. And remember the upper and lower arms travel in arcs- you dont want uppers too stiff or they'll try to bind the suspension


You mean Heim joints? Should I use them one just the uppers or both upper and lower. I would think just one end would be best, right?

[Norm Peterson]

Link (http://www.jonaadland.com/Z28/Mods/LCA/AluminumLCAs.html)

Make two sets, lengths as appropriate. Note the "Double Rod Ended LCA's ride too harsh for you? Try Rubber in one end:" part.

Adjustable length UCAs allow you to fine-tune pinion angle and center the axle under the chassis. Adjustable LCAs allow pinion angle and thrust angle tweaking.

Rod ends in one arm end eliminates one of the two sources of "roll bind", presumably the larger especially with either boxed or tubular cross section arms that are torsionally much more rigid than the OE stamped open-section arms. It takes two per arm to eliminate all of it.


Norm

[slowcamaro]

Link (http://www.jonaadland.com/Z28/Mods/LCA/AluminumLCAs.html)

Make two sets, lengths as appropriate. Note the "Double Rod Ended LCA's ride too harsh for you? Try Rubber in one end:" part.

Adjustable length UCAs allow you to fine-tune pinion angle and center the axle under the chassis. Adjustable LCAs allow pinion angle and thrust angle tweaking.

Norm


It might be cheaper in the end just to buy premade ones from hotpart or a similar supplier if you can find them in the correct lengths. I made my own and after paying for quality rod-ends I think I ended up spending more.

[The Stickman]

Link (http://www.jonaadland.com/Z28/Mods/LCA/AluminumLCAs.html)

Make two sets, lengths as appropriate. Note the "Double Rod Ended LCA's ride too harsh for you? Try Rubber in one end:" part.

Adjustable length UCAs allow you to fine-tune pinion angle and center the axle under the chassis. Adjustable LCAs allow pinion angle and thrust angle tweaking.

Rod ends in one arm end eliminates one of the two sources of "roll bind", presumably the larger especially with either boxed or tubular cross section arms that are torsionally much more rigid than the OE stamped open-section arms. It takes two per arm to eliminate all of it.


Norm

WOW thanx for that link. I have some of that tubing and never considered it for suspension arms. I didn't think they would be strong enough. Not only would they be stronger but tons lighter. Very little fab work too. That changes the whole game now doesn't it. Thanx so much.

[jackfrost]

you could also use Currie Johnny Joints instead of rod ends:
http://www.currieenterprises.com/CESTORE/product.aspx?id=1262

[claytonisbob]

I've been contemplating buying some normal tubular control arms, cutting one of the bushing housings off and welding a johnny joint on one side... untill I came across this thread.

The link mentioned earlier in this thread to:
http://www.jonaadland.com/Z28/Mods/LCA/AluminumLCAs.html#Update

The guy makes some really simple looking lower control arms using rod ends and 6061 hex aluminum. They are light and pretty good looking too.

https://static1.pt-content.com/images/pt/2009/01/NewOldLCA2JPG-1.jpg

Now I'm not wanting to use Heim joints, but johnny joints with threaded studs (one side only) and bushings on the other side.

https://static1.pt-content.com/images/pt/2009/01/ce9112sp-1.jpg + https://static1.pt-content.com/images/noimg.gif + https://static1.pt-content.com/images/noimg.gif

The rods are only $16 to $17 each, jjoint ~ $40 each, the bushing ends are ~ $32. All in all, should be looking at $200 total after shipping and misc. I'm planning on using a rear sway bar that doesn't attach to the lower arms, so thats not an issue to me.

What do you think? For not having to weld anything, and to have nice, strong, light arms I think is pretty cool. I might be missing something though.

[slowcamaro]

Save yourself the trouble at the $200 price point its very likely that you can find something that fits your needs already produced.

here is something similar, though not adjustable.
http://www.hotpart.com/shop/index.php?l=product_detail&p=85

Click through their other products before you decide. As I stated before, by the time I built mine I could have just ordered them complete.

[claytonisbob]

If they had those for a Chevelle for that price I may buy them, but I haven't seen them.

Currie used to make arms similar to those for A bodies, but they changed them to billet aluminum and raised the price. I haven't found A-body arms with those joints other than those from currie, and their new (aluminum) ones are almost $400 for a pair. For $200 I think putting some together may be a little trouble, but I think it would be worth it.