fj control arms on an xj

[hotrod07]

the lca's are 27 and the uca's are stock at the moment

 

[cal]

You think he did?


Was there anything really good on that thing? Why'd he sell it so fast?

I was trying to be nice.


The front axle was pretty good. It looked like a duck-billed platypus, but it was solid.

 

[Goatman]

the lca's are 27 and the uca's are stock at the moment

It makes a difference what joints are in these arms. I'm assuming since they are stock arms that they are rubber bushings. What width are the bushings/mounts?

Ideally, the frame side mounts would be inside the frame, but that might be hard to do with a 27" arm. That means you'll have to mount the arm below the frame rail. I'd use a bracket like this one from Poly Performance:

You'll still loose some ground clerarance with the mount below the frame, but it will be better than those who mount a 36" arm below the frame or have the links mounted to a crossmember that hangs below the frame (which is a bad idea, BTW).

If you limit the downtravel of the front axle I think you can make it work with the stock arms. It's not ideal, but plenty of things aren't ideal. The idea on limiting the down travel is to keep the pinion yoke and u-joint from binding. This will be an issue since the UCA's will be 12" shorter than the LCA's, so the arc of movement of the uppers will be more then the lowers which will rotate the pinion down when the suspension droops. If you want, you can just make sure that your shocks aren't long enough to let the axle droop to the point that the u-joint binds, with a little margin of safety.

The best thing to do would be to make the upper arms longer, like 20-22". It's not real hard to do, just material to make the arms. I went through a lot of work on my XJ moving the frame side mount of the upper arm. Then on the XJ buggy I realized that the heim joint with a high misalignment spacer has plenty of movement for the arm movement when the joint is mounted vertically rather than horizontally (the bolt vertical rather than horizontal). This makes it real easy to make a new mount since the tabs can be welded to the inside of the frame without working out how to get the bolt through the frame. Here's a pic of what I did, just plated the inside of the frame and welded on the mount.

 

[muddy xj]

i have the wj arms on my jeep and i didnt cut the bushings or anything...i just took a long bolt and a nut and spread the brackets to fit the bigger bushing and i havent had any problems with that...i will eventually be putting long arms on my jeep when i lift it to 5 or 6in but the wj arms were 50 bucks at a pick n pull and brand new from the dealer the would have cost me 200