Harsh (Jarring) side to side after lift

[rolling7high]

I had all the same issues you described with my 4runner after the lift. This has been my experience: All the rear control arms and tolerances are set for factory height. When a 4runner is lifted the angle of the control arms change, rear axle moves forward, and the tolerances are exaggerated. What I mean be rear axle tolerances are exaggerated is that the rear axle is to be squared with the front tires within 3/16 of an inch, when the 4runner is lifted it changes how square the axle is. The back axle not being squared is causing the back "waggle." I learned this all the hard way. To solve the problem, I installed adjustable rear upper, lower control arms, and adjustable pan hard. I adjust the pan hard so the axle was centered within the frame and then I squared the rear axle to the front tires by adjust the control arm. Once I did this, the 4runner drives like stock again.

 

[Slodrivr]

I recently put 255/75/17 Cooper S/T Maxx on. Was previously on 265/70/16 Cooper M+S. I immediately noticed less stability and tracking at speeds over 50 mph. Rear end waggle over big bumps and expansion joints definitely increased. I haven't chalked the new tires yet, so inflation may be part of the issue. Or it may be the tread pattern. Hard to say since so many people like these tires. Also it's kinda hard to believe that 10mm would such a big difference in handling. I've got a set of spidertrax spacers to see if increasing track width will restore sports car like driving pleasure at mid to upper double digits.

Rolling7High - where did you get adjustable upper arms?

 

[4Runnin2000]

So I'm starting to think I just need to live with the way it drives. I will check a few things this weekend that have been mentioned on this post and see if there are any little things that might help. I will check Panhard bar and get a pry bar on the control arms. Maybe one of those will help. If not, I will just live with it as long as it's not damaging anything.

 

[4Runnin2000]

I had all the same issues you described with my 4runner after the lift. This has been my experience: All the rear control arms and tolerances are set for factory height. When a 4runner is lifted the angle of the control arms change, rear axle moves forward, and the tolerances are exaggerated. What I mean be rear axle tolerances are exaggerated is that the rear axle is to be squared with the front tires within 3/16 of an inch, when the 4runner is lifted it changes how square the axle is. The back axle not being squared is causing the back "waggle." I learned this all the hard way. To solve the problem, I installed adjustable rear upper, lower control arms, and adjustable pan hard. I adjust the pan hard so the axle was centered within the frame and then I squared the rear axle to the front tires by adjust the control arm. Once I did this, the 4runner drives like stock again.

Thank you for the explanation. It makes sense that by lifting it, it throws off all the geometry of the suspension. I guess they need to just start lifting them from the factory. Haha

 

[psraff]

I had all the same issues you described with my 4runner after the lift. This has been my experience: All the rear control arms and tolerances are set for factory height. When a 4runner is lifted the angle of the control arms change, rear axle moves forward, and the tolerances are exaggerated. What I mean be rear axle tolerances are exaggerated is that the rear axle is to be squared with the front tires within 3/16 of an inch, when the 4runner is lifted it changes how square the axle is. The back axle not being squared is causing the back "waggle." I learned this all the hard way. To solve the problem, I installed adjustable rear upper, lower control arms, and adjustable pan hard. I adjust the pan hard so the axle was centered within the frame and then I squared the rear axle to the front tires by adjust the control arm. Once I did this, the 4runner drives like stock again.

I would like to know more about this. I've searched some in the past without luck about at what point, height wise, should we start to look at adjustable Uppers and Lowers? The panhard bar is a given... If we need to get the rear square again to the front, what is the stock measurement from front to rear? Or do we care, as long as it's square? What are the steps in doing so? Set the lower first, or uppers, or.....?

I searched a few times for these issues without luck. Does anyone have any insight?

 

[JRZEE2000TR4LTD]

I had the exact same problem with the exact same setup. Adjustable Panhard bar fixed me up. Look at where your tires are on each side. Does one side stick out more than the other? Mine was out about an 1" after the lift.

 

[4Runnin2000]

I had the exact same problem with the exact same setup. Adjustable Panhard bar fixed me up. Look at where your tires are on each side. Does one side stick out more than the other? Mine was out about an 1" after the lift.

My tires are even on both sides. Although I believe the Panhard drop bracket is what fixes that. But I'm wondering if my bar is a little loose from side to side. Just seems to easy to take in and out.

 

[rolling7high]

I would like to know more about this. I've searched some in the past without luck about at what point, height wise, should we start to look at adjustable Uppers and Lowers? The panhard bar is a given... If we need to get the rear square again to the front, what is the stock measurement from front to rear? Or do we care, as long as it's square? What are the steps in doing so? Set the lower first, or uppers, or.....?

I searched a few times for these issues without luck. Does anyone have any insight?

I would say it depends. If the 4runner's rear alignment is out of square then steps are needed to re-square the rear axle. The only way to square the axle is with the adjustable lower control arms and adjustable pan hard. First, adjust the pan hard so the axle is centered. Second, adjust the lower control arms to make square. I first crossed measured for square and then measured front to back. Upper control arm changes pinion angle.