I did some searching on this and didn't find it, so I apologize if it is a repost.

Is it better to change upper or lower control arms? Every time I have bought a lift in the past it has came with lower control arms. I have seen lately many people changing their uppers instead? Wouldn't adjusting the uppers inward pull the axle forward out of its original alignment with the springs/sway bars/ etc?

I am about to get rid of this 2" superlift and go with a OME HD kit which will net 3" I have read and I don't want to have any issues. I also don't want to spend cash I don't have to. So with the OME kit will I need adjustable uppers, lowers, or stock control arms to maintain proper steering and control?

 

Front lowers and rear uppers will set you straight.

 

I have the same question.

Why not the front uppers only? Why are usually just the lowers replaced. Al you need to do is move shift things a few degrees. Is there an advantage to one over the other?

 

I actually went with the FT uppers first, 'cause it was cheaper and it gave just enough adjustment to set the caster to about 5 degrees with the OME HD front springs and 3/4" spacers (FabFour front bumper, Warn 8000 winch).
I have since added the lowers but was pleased with how it drove with the uppers only for sure.

But if doing it over I'd spring the extra for the lowers only, it would give greater adjustability, as well as space the axle out the little bit needed with the lift.
However, it could cause your front trackbar to be closer to your differential cover.
It might have been an issue with my FT front trackbar and the ARB cover I'm running if I hadn't done the uppers first.
See, I have my FT upper control arms 1/8" shorter than stock and then I added the lowers which are extended a bit further to give 7.1 degrees of caster.
With full length upper control arms it'd be damn close by my estimates, 'cause there ain't much clearance now but it's never hit.

Consider your components carefully.

 

Font uppers only does get the job done. However, when doing just the uppers you end up with an arm that is shorter than the factory arm. Longer is always better, so do the lowers and make them longer.

 

Plus, most after market lowers will take alot more punishment than stock arms, I have the Teraflex lowers and they weigh twice as much as stock arms.

 

Now that is a great reason.

Other than that though, I am not sure I get it. Why is it better to have longer than stock arms rather than shorter?

Technically, to be perfect, you would replace both upper and lower, shortening the uppers and lengthening the lowers, right? This would keep the axle exactly where the factory put it, just change the caster angle.

Lots of things get said here, but I am wondering "why is one better or worse than the other?", and I am not hearing that. I had a tech at an unnamed off road parts store tell me that I could not replace just the uppers...because no one does...just because.

 

What he said. ^ if you need more info than that read this. https://www.jk-forum.com/forums/modified-jk-tech-2/multiple-manufacturer-assembled-suspension-lift-44547/

 

I appreciate that, and I really like the way you did your lift. You get what you want and nothing you don't need, and keep the cost down. Very smart, I think. Kits I was looking at either had stuff I already had or did not want, or did not have things I wanted and would have to buy seperately later anyway. I did mine kinda the same way, but I still have a ways to go. I did not do mine all at once.

Having said that...We still do not have an answer to the upper vs. lower control arm question.

I know that both is best, but you proved that both are not necessary, at least right away.

Now to the question of, "Is one better than the other, and if so WHY?"

I am heading towards having a fabrication buddy make my uppers adjustable for next to nothing, as long as there is not a real good reason to do the lowers first.


I am not hearing any informed reasons not to go with upper adjustable arms, so I may just do it and see for myself.

Still open to informed advice, if it answers the question.

 

Uppers only do not afford you enough adjustability before you run into problems with the frame body and axle pinion angle.

As was said before for adjustability you need front lowers and rear uppers only. In fact I have proven that all you need is front lowers to bring the flighty steering into control. I ran all stock control arms on 4 inches of lift for 5 months without a problem.