Is it possible to only use adjustable upper rear control arms?

[box12360]

I'm in the process of doing a 4 inch lift. My questions is I have metalcloak adjustable control arms- a set of lowers and upper rears. I'm piecing this lift together. Is it possible to only use the upper's in the rear and stock lowers to adjust my pinion angle for the sye/DC drive shaft? Use the adjustable lowers up front and stock uppers to make adjustments for the front.

The end game is to have all adjustable control arms but for now with all of the other cost to run a (well put together) 4in lift If i can make this work I will, if not i will bite the bullet.

 

[Chris]

Yes, all you technically need is the adjustable rear uppers to set the pinion angle. However, at 4" of lift, you really want adjustable control arms all around, so that you can also dial in the caster in the front as well.

 

[jjvw]

It can be made to work. But there will be compromises. Cycle the axles to see what those are.

 

[box12360]

It can be made to work. But there will be compromises. Cycle the axles to see what those are.

By compromises do you mean front Caster angle? Or that it will possibly bind (front and rear)

 

[jjvw]

By compromises do you mean front Caster angle? Or that it will possibly bind (front and rear)

Maybe. Among other things.

If all the control arms are adjustable, then the axle can be better positioned to accommodate all the various movements it goes through during the travel cycle.

There is an idea that the upper arms adjust one thing and the lower arms adjust another. This is very inaccurate. All the arms are used to position and roll the axle within it's space. By not having the greater adjustability of all four arms, there is the risk of creating interferences with the gas tank, wheel openings, steering and track bars, etc. These may require more bump stop extension than might otherwise be needed.

 

[-T.]

I've run my Jeeps forever with that set up in the rear. You may have a little issue with the rear trackbar touching the gas tank skid, but it can be clearanced a bit. A better option is to add an adapter to relocate the track bar. I have the one from JKS that moves the track bar up and forward a bit, so it relieves a little stress on the bushings created when you rotate the rear axle to point the pinion up. I also had to add brackets to move the rear shocks out a bit to keep the shock bodies from contacting the rear spring perches. I'm not sure that adjustable lowers would alleviate any of these issues, as I just don't have any significant experience with them. I've always run fixed lowers. Either stock or aftermarket.
For the fronts, the adjustables may be a good idea to try at 4". I had one early TJ with the Dana 30 and I was able to run fixed arms all the way up to 5" and had enough adjustment in the front with the standard cam bolts, to keep it going down the road well. However, on my newer TJR, I was fighting death wobble after installing OEM arms on it. Then I noticed the aftermarket fixed arms that originally came with the Jeep when I bought it (Superlift) were slightly longer than the stock arms, so I put them back on and it helped, although I was replacing a lot of parts around the same time. This is why I say it might be good to have some additional adjustment up front. Best bet is to just try it all out, but I think the rear should be fine running adjustables on top only. It will be interesting to hear what you come up with.

 

[bobthetj03]

It's working for me right now, but it's not ideal. My rear track bar kisses the gas tank skid at full droop.

 

[box12360]

Well looks like im going to be running a Metalcloak/Currie hybrid, guy had a set up brand new Currie adjustable uppers for the front for a price i could not pass up... Ha I could get Currie lowers and see if the Metalcloak or Currie’s last longer If anyone has any lower adjustable CA Currie, Metalcloak, Savvy I could be interested, lets get real saucy and do a Metalcloak/Currie/Savvy build lol

 

[Gollywomper]

The axles do not pivot on the centerline when adjusted with only uppers or lowers. The axle moves forward or backward depending on whether tops or bottoms are adjusted.
So in the rear, if you only adjust the uppers, the axle will move backwards as well. This is because how the lowers are mounted in relation to the axle centerline. So doing it with just uppers sometimes causes the diff cover gas tank clearance issue or tires rubbing the rear of the wheel well. With all adjustable arms you can put the axle where it needs to be in relation to bump stops and centering your tires when they are stuffed to prevent unnecessary rubbing. I didn’t really understand it until I cycled my rear and made adjustments to center my tires at full stuff. What you have will work, but all 8 adjustables are ideal for proper setup.

 

[Nep1303]

Yes, all you technically need is the adjustable rear uppers to set the pinion angle. However, at 4" of lift, you really want adjustable control arms all around, so that you can also dial in the caster in the front as well.

Would I be fine doing only upper rears for a 3 inch lift? Or would it be recommended to do all adjustable

 

[Gollywomper]

Would I be fine doing only upper rears for a 3 inch lift? Or would it be recommended to do all adjustable

It probably work. Ideally you want adjustable lowers as well. Just tilting the pinion up using only uppers causes the axle to move back aways and can cause it to hit the gas tank skid or tires to hit rear fender openings when flexed or hitting large bumps.

 

[Chris]

Would I be fine doing only upper rears for a 3 inch lift? Or would it be recommended to do all adjustable

It would work but it’s not ideal. I’m a firm believer that you do something the right way and you do it once.

 

[Nep1303]

It probably work. Ideally you want adjustable lowers as well. Just tilting the pinion up using only uppers causes the axle to move back aways and can cause it to hit the gas tank skid or tires to hit rear fender openings when flexed or hitting large bumps.

Would a long arm kit work the same as an adjustable kit?

 

[Nep1303]

It would work but it’s not ideal. I’m a firm believer that you do something the right way and you do it once.

Would that mean do upper and lower or front and rear?

 

[never monday]

Would a long arm kit work the same as an adjustable kit?

No

 

[never monday]

Would that mean do upper and lower or front and rear?

Upper and lower

 

[jjvw]

Would a long arm kit work the same as an adjustable kit?

If the long arms are adjustable then they should adjust as well as a short arm with adjustables.

 

[never monday]

If the long arms are adjustable then they should adjust as well as a short arm with adjustables.

You’re leaving out the good parts

 

[jjvw]

You’re leaving out the good parts

The good parts get tiresome to repeat over and over!

 

[Chris]

Would that mean do upper and lower or front and rear?

Yes, a complete set of 8.