mphilleo

First off, I'm glad to be here! This is my first JK, but I've had numerous XJs, ZJs, a WJ, even a couple YJs, so I'm definitely a Jeep guy. That said, this is kind of a long post, but I'd appreciate any input if you have a couple minutes to burn reading to the end.


So, here's my '12 JKU Sport. She came with a very used up Rough Country 3.25" lift (with 32.5" tires) that was very tired and had some issues. I started off by installing some Rancho geometry correction brackets, then took it to the alignment shop. They suggested adjustable track bars would be a good addition so they could correct the thrust angle of the axles. Although the ride/steering quality improved a lot, I was still having some issues with tracking and also rubbing of the rear sway bar on the passenger side tire. I took it back to the alignment shop and the master tech took it for a test drive and had it for 4 hours. He said he went over everything with a fine tooth comb and although he agreed about the steering and handling, there weren't any other adjustments to make. According to him, getting the axles in line exposed other issues, like faulty shocks (true) and that a stiffer sway bar would improve handling and wind buffeting overall (I live in North Dakota).


The Rough Country 2.2 shocks that came on it were toast, so this seemed plausible. I took a day off of work and took my time giving her some overdue love, putting on new Mopar front sway bar links, a beefier Hellwig rear sway bar, and Rancho RS9000XL shocks on all four corners. After all that, the ride is much improved and the Jeep definitely tolerates wind buffeting a lot better. But the steering feels like it either turns left or right, with little on center freeplay. You turn it a little left or right and it will start going that direction. I'd describe the tracking as "straight to a fault" in that the JK wants to follow the crown of the road slightly enough that I need to make minor steering corrections for it fairly often. But if I put myself on a flat road, it doesn't really wander. The other issue is that the rear sway bar is that the Hellwig sway bar is still very close to the rear tire, enough for a good amount of sidewall flex to rub (maybe 3/8 to 1/2 inch). I've since confirmed that the axles are indeed aligned, and tried to readjust and re-secure the sway bar, but it just keeps finding its way close to the tire.


Either way, thanks for reading through to the end if you made it this far! But I'd be curious if any of you ever heard of or experienced this? Can you suggest a solution? I can't tell whether these are "JK things" or I'm just being knit-picky.

resharp001

I would say your biggest issue is the 6.25” backspacing on the factory wheels. Solution would be running 1.5” adapters or moving to a wheel with a BS that will accommodate the larger/wider tires most want to run. I would not have changed the rear swaybar, but too late for that. Many people don’t even run a rear sway bar on these things, and the factory sway bar in back being a bit wimpy allows for that rear axle to flex a bit. Your stiffer sway bar is going to limit articulation. I’d worry about the wandering issue if it was doing that on a flat road, but if you correct for it wanting to follow the crown of the road, it’s only then going to wander when on a perfectly flat road.

nthinuf

Certainly not a cushy luxury car, but no, I'd suggest you keep asking and gathering data rather than just write it off as a jeep thing.

Just for some added background info:

Did the alignment guy give you a printout? If so, what are the current specs? (my thought here is that the lift came with components to raise the Caster. Then you added brackets to raise the Caster again. Curious if the tech left it alone, lowered, raised...)

So after looking at it yourself, you agree that the axle is centered left-to-right under the jeep? Or you looked at the printout and called it good?

What is the sidewall size of the tires, the load rate, the psi?

mphilleo

Thanks for information. I've been avoiding putting on spacers, not because I'm too cheap, but because I'm told that puts additional strain on the bearings and some suspension components. Truth be told, once these tires are worn out, I'd probably buy a tire with an aspect ratio that's in between this and stock. I suppose the alignment shop was right to say that a guy needs adjustable trackbar(s) to center the axles when I asked them to perform the service the first time. But I measured the trackbars after adjustment and they're very close, if not the same, in length as my stock ones...so maybe that wasn't necessary like you had said. Dang it.

Thanks for following up with me. I don't have a picture of the alignment print outs on hand, but I will post the first and second ones when I get home tonight.

Regarding the axle centering, The only thing I could do on my own last night was measure the distance from a common fixed point on the frame (in this case the middle body mount bolt) to the center of the rear wheels. They matched each other from that measurement. I did the same thing for the front axle from the front body mount bolt to the center of the front tires and they matched too. Funny enough, I don't think the print out actually has anything for thrust angle. I didn't calculate my own degrees/radius since those values seemed correct. Not to go overboard on detail, but I had decided to measure the length of the now-adjusted adjustable front and rear track bars and they were roughly the same length. So either the adjustment needed was very small or virtually nothing.

I've included a picture of my tire, it's Nitto Terra Grappler G2. I currently have them all at 32 PSI, which I did to see if it helped with the Jeep wanting to follow the crown of the road as well as comfort.

Sixty4x4

I think Nuthinuf is on to it with the caster issue. You should be between 4.6ish to 5.5 max positive. When I did my 3" MC system I did not put the adjustable lower control arms on and it wandered. Once I installed the LCA's and adjusted caster to 5.5 it was a different vehicle to drive.

mphilleo

Thanks for the feedback! One thing that was interesting was when I initially brought the Jeep in for its first alignment after the Rancho geometry correction brackets were installed, I provided the specs from Rancho for correcting caster with the brackets installed. But it looked like they never actually took the sheet I provided for them. Would you think it might be worth taking it to an alignment shop that will get me lined up with those specifications? It's possible that if that was never properly done, along with all the other changes I've made, that I'm out of whack.

nthinuf

When you post that alignment info, also let us know which version of correction came with the lift. (cam bolts, fixed arms, etc). At least it will help us with whether Caster could be a contributing factor, and if so, how much adjustability you might have.

mphilleo

Like I mentioned, the previous owner was the person who got the lift, but I'm 95% sure this is it (due to having the trackbar relocation bracket and measuring the suspension also verified this for me):
Rough Country 3.25 Lift Kit

Here's the pictures of the alignment. The first one is the initial alignment I got after having the Rancho geometry correction brackets installed:




Here's the second and most current alignment after the adjustable front and rear track bars were installed. When I picked it up, I noticed the location of the rear sway bar had not moved off the tire, so I had them take it back in and align the axles (I asked for this and apparently they didn't). The 3rd visit I had after their lead tech looked at it after 4 hours had no print out with it.



Hopefully that clears things up a bit. If I can provide any other info, let me know. Thanks!

EDIT: These 30570R17s are getting a little long in the tooth anyway. The wife and I are toying with the idea of putting stock 25575R17s on so we'd be down to 10" wide tires. Can any of you confirm whether this would resolve my clearance issues? I assume the lift with stock tires should work fine, right?

mphilleo

Any insights from anyone based on the alignment results I posted?

resharp001

I think the alignment specs look fine. Caster is well within an acceptable range for a lifted JK. I don't believe caster is the issue. If the jeep drives straight as an arrow on a flat road, but wanders when the road has a crown, I don't believe there is anything to do. More narrow tire or a wheel with decreased BS should fix your issue rubbing issue. I know I said that before but I'll stick to it. The only thing I might say about decreasing tire height by over 1.5" and width by 2" is it might look a little disproportionate with that much lift. All subjective though.