Long arm build questions.

[CSaddict]

I am getting ready to buy the materials to make the long arms for my XJ. I have a question. I see that Clayton uses a Johnny joint at the cross member for the lower arm and one at the top arm to lower arm joint. What purpose does this serve if the top and bottom geometry stays the same?

I plan on using a Johnny joint at the crossmember end and a urethane bushing in a sleeve at the axle and at the upper joint to the lower arm joint. Any reason I can't?

Thanks for your input. Im still on the fence of using 1.75 or 2" DOM or just use 2" square tubing. Both .250 wall. I figure the square will be cheaper and take hits better.

[KtmRacer419]

looking at steves setup (joker4ink) i remember seeing all johnny joints except for on the axle end upper control arms.

basically, as long as there are rubber/poly bushings somewhere on the arms your good.

they are basically just to keep the upper arms from flopping around and messing with your caster.

Personally I run rubber bushings on the body end of the arms for most road noise isolation (not that it matters in my jeep anymore)

having the bushings there also allows me to run shocks on my arms. (longer shock options and greater range of travel when put there) if the lower arm only twists at the axle end heim joint then the main body of the arm stays relatively in place allowing me to mount a shock on them.

[CSaddict]

Good point about the insulation but then I would need a heim or Johnny joint on the top arm too. I am also looking at mounting to the frame. Weld on some mounts on each side (like I think you did) or build a full length cross member. I think a mount on each side will do like the RK system. Got any pics of your mounts to the frame?

[KtmRacer419]

EDIT: these pics are old. my shocks are now mounted on the arms (i dont have pics of that though)





you might have some better pics on your broken camera;)

good thing you brought that up though. you need at least one rubber bushingin the "y" portion of it (stock bushing should do) to compensate for the binding inherint (sp) in a radius arm design.

I chose to run only one upper control arm. to make caster adjustments as simple as the turn of a arm (rh and lh thread)

and if you choose to run only one upper arm i strongly reccomend running all heims up there (to compensate for axle hop) and running a larger bolt at the uca axle end (10mm wont cut it)

[CSaddict]

I plan to run 2 upper arms. I think I am going to make individual mounts for each side like the RK set up.

[CSaddict]

What size tubing it that?

[KtmRacer419]

i want to say the lowers are 1.5"(maybe 1.75") solid stock. and the upper is 1.5" with a 1/4" wall.

[crosbike]

sam...whats with the sticks duct taped to your hood?

[KtmRacer419]

it was a jeepforum owning project, which was successful

[crosbike]

link? where do u go to school?

[KtmRacer419]

www.jeepforum.com/forum/showthread.php?t=436513

and

New England Tech