Length of adjustable lower control arms

[Jason7140]

From what I have read, Rubicon express's fixed lower control arms for their 4.5" kit set a 16". If this is wrong some one let me know. I have 4" of lift on my LJ with stock control arms and I am installing the new adjustable lowers and rear uppers this weekend.

What should I set the lower control arm length to with 4" of lift?

How about the upper rear arm length?

I believe 16" will work for the lowers.

 

[SteelHeadz]

IMO, the best answer is what the alignment specs. recommends as the optimum setting. It's final adjustment will set the caster and also will affect the camber as it tilts the axles.

 

[Bounty__Hunter]

It will affect caster but I don't see how it'll affect the camber?

If you're using fixed upper control arms in the front, you want to set the lowers for proper caster, which is about 5-8 degrees. Often it's a compromise between good caster and a good pinion angle, so you will likely be closer to 5 degrees.

I ran 17" lowers on my MJ with 5.5" coils but I also lengthened the stock uppers by 1", so 16" should get you in the ballpark, at least close enough to get it aligned.

 

[SteelHeadz]

Yup, enough tilt on the axle will roll the up and down position of the upper and lower ball joint and will change the angle of the camber due to the slight off set of the upper and lower ball joint knuckles.

 

[Jason7140]

After measuring my factory arms while installing the adjustable arms, I determined that a half an inch longer would most likely do the trick. I set the lower arms all to 16.25" and a week later the death wobble hasn't returned.