Fabbing Lower Control Arms

[terryd]

ok, found the awnser to size of tubing on naxja, gonna be 2"od 1/4 wall, but was wondering if the bend you see in most lca's was really needed and just what exactally it was for? i've heard of tire clearance if you're using stock wheels, but does it serve any other purpose? and for a medium core ride, are there any advantages of heims over the RE superflex joints?

[Bubba_Jeep]

To bend or not to bend your LCA's will depend on where you attach them to the frame, and what your wheel back spacing is. In other words, your particular set-up will dictate clearance issues. I'm running short-arms, 12.5 inch wide tires on 10 inch rims, and 4.5 inches of back space; my tires don't rub on the arms, so bending for clearance was not needed. The second reason to bend the arms, in a vertical plane, is for ground clearance when running long arms. Appears to work if the arms are attached inboard of the frame rails, IE, to the trans cross member. You need to look closely for potential clearance issues as the arms move upward during compression. I, personally, haven't spent much time considering bending my arms, but a cursory glance gives me reason to believe I would have problems with clearances because of my Chevy install--it pretty well occupies all of the space, and what it didn't use, my HP D44 uses
I'm using the Currie joints at the frame-end of my LCA's. There's a ton of posts discussing the pros/cons of using rod-ends. I, personally, would use the Curries, or RE's. I think they are quieter, and have a longer life (they are rebuildable) than rod-ends. I'm sure in some applications they allow better articulation, but my XJ is not on that level.

[terryd]

sweet bubba, searching on naxja, i found a thread on bending them on the verticle plain to keep them from contacting the axle bracket and limiting flex.... this is a short arm setup btw. 2" 1/4 wall strong enough to take the bend on the lower end and not get all freaky during braking or turning? also, what bushings did you use on your's, i found some on poly performance (same place w/ the superflex's) but i'm not sure i like the design.. i'd like some that just slip into a tube on the lower end instead of being inside a houseing, pressed into a tube.....

[Bubba_Jeep]

For a short arm set-up, 2x.250 tube would be OK. I'm using .125x1.5x2.5 rectangle, with a bend at the axle end. They are Tomkin arms I modified to accept the Currie large JJ (2-5/8 x1.250-12 welded stud). The axle-end bushing is the two-piece polyurethane that came with the arms--I've seen similar bushings with DOM shell advertised for DIY's. I bought the JJ's, threaded adapters, and DOM tubing from Polyperformance. Here's a shot of my passenger side arm.

[Goatman]

Originally Posted by terryd

sweet bubba, searching on naxja, i found a thread on bending them on the verticle plain to keep them from contacting the axle bracket and limiting flex.... this is a short arm setup btw. 2" 1/4 wall strong enough to take the bend on the lower end and not get all freaky during braking or turning? also, what bushings did you use on your's, i found some on poly performance (same place w/ the superflex's) but i'm not sure i like the design.. i'd like some that just slip into a tube on the lower end instead of being inside a houseing, pressed into a tube.....

You don't need to bend them for axle bracket clearance. A couple of manufacturers do it because they want their stuff to be bolt on, but it doesn't need to be done and is actually lame to do if you're building your own. You just cut or grind some metal off the bracket, which is where the shock mounts. Quite a bit can be cut off without compromising the strength of the bracket, making bending the arm needless.

Johnny Joints are good choices for arms, and any of them will work fine. Some like RE's since they are easier to tighten when they wear a little, some like Currie's because the plastic race is tougher and they last longer........you choose. You can also use rod ends, but the lowers need to be bigger than 3/4 inch, and the bigger rod ends are more expensive.....sort of defeating the purpose if you're trying to save money by building your own arms.

I think 1/4 wall is the minimum. I'm assuming you're using DOM. If using HREW, you should sleeve the arm with a smaller size tube inside the outer tube.

[Bubba_Jeep]

The vertical bend in the LCA I was referring to was not to clear the CA axle mounts. It is to add ground clearance on long-arm set-ups. My LCA's have a bend in them for axle mount clearance--I didn't know a lot back when I bought them--seemed like a good idea at the time. Now, they're totally superfolous to my set-up, but they don't hurt anything, either. Eventually, I plan on either an intermediate 4-link, or a long arm 3-link.

[Goatman]

Originally Posted by Bubba_Jeep

The vertical bend in the LCA I was referring to was not to clear the CA axle mounts. It is to add ground clearance on long-arm set-ups. My LCA's have a bend in them for axle mount clearance--I didn't know a lot back when I bought them--seemed like a good idea at the time. Now, they're totally superfolous to my set-up, but they don't hurt anything, either. Eventually, I plan on either an intermediate 4-link, or a long arm 3-link.

I knew you meant that....on the long arm setup. The Y link like from TnT is a pretty cool design. I was talking about on the short arm setup like he's going to use.....and I said when building your own arms.

[terryd]

i got to thinkin about that at work tonite. thinkin grind a little off the mount and maybe scabb it with a little 1/4 plate or something like that. i'm gonna use DOM for this, no HR in suspention parts. i took machine shop in HS and have a basic understanding of metal strength. thanks for the input!