Jeep Geniuses,

Need some help/ shared experience on a control arm question. I am putting together a 3" lift for my 2DR JK and have been getting mixed message about the necessity of control arms and which arms to buy. From reading the awesome "newbie" area of the forum, I see that front upper and lower control arms are suggested to adjust caster and that a new double cardin rear driveshaft is suggested due to drive shaft angles. I have been told by a couple of reputable 4WD vendors that front lower and rear upper control arms alone will control/fix/improve both the caster and rear driveshaft issues.

Any thoughts on which one is right? Can these adjustments be done with this control arm set up? I'm obviously trying to do this on a budget so saving $250 by only using one set of arms would be great.

THX

 

Yep. If you only want to buy four arms then front lowers and rear uppers are the way to go.

 

That is contrary to my understanding. I believe uppers adjust angle and lowers adjust distance (center axle) regardless of front or rear.

 

This is correct but getting front lowers will allow for minor caster adjustment just as cam bolt would - without having to notch out your axle mounts of course. Optimally, you would want both as just doing lowers alone might cause your coils to warp a bit and enough so that they might make contact with your bump stop tower.

 

Is there anything to look out for if you do ONLY front/rear uppers to adjust drive shaft angle/castor?

 

The rears will be fine and there shouldn't be anything to look out for but up front, you might find that some uppers cannot be shorted enough to give you the caster that you want.

 

I have some FT front uppers on the way (rears as well). Would you expect these fronts to adjust short enough (no lowers)?

 

You will be ok with just the uppers, I is just not the recomended way to go. I had to buy my lift in stages for pricing reasons. I started with the the front lowers and bought the rest as the money came along.

 

You can get about +5 by extending your front lowers, with stock uppers on the front. If you want more, then yes, you will need front uppers as well. I picked my stuff up in stages as well and now I do have all uppers and lowers. I did, at one point, just haver front lowers and rear uppers with no problems. I'm just not a fan of shortening my control arms, that is what you will end up doing if you just have front uppers.

 

Thanks for the info all. So here is a follow up question...if you had to choose (current mod budget limit) for the front lower and rear upper control arms or the new rear driveshaft, which would be "better"? Does the control arm install provide more benefit (caster and pinion angle improvement) than the driveshaft upgrade? This is probably an "apples and oranges" thing, but if I'm spending $400-$500 I'd like to get the most bang for my buck. If I do the control arms, I'd likely be running the stock driveshafts for another 10K miles or so (hopefully!)