I've just purchased my first jeep ... a 2010 JKU Rubicon. From what I can tell it has a 2.5" RE lift. It had 35/12.50r20 Toyos and actually rode pretty well, especially on the hwy. I wanted less pounding and more sidewall, so I put on 315/70r17 KO2s. I like the ride , but the swap has introduced a slight clunk that wasn't there before. I only hear hear it at low speeds and can't pinpoint the cause. It seems like it's coming from the drive side pillar or roof line, which seems odd to me. I assume it's transferring from the suspension, but who knows. I'm wondering if the wheel diameter change was enough to throw the control arms out of alignment or something. Sometimes I feel like I can slightly feel it transfer through the steering wheel ... But that may be me overthinking things. All in all, it drives great. Any thoughts?

Thanks in advance ... Chris

 

No, changing the wheels and tires will do absolutely nothing to the alignment. If the tires are worn badly or have flat spots you would notice something from that. Make sure your wheels are mounted correctly and are torqued correctly. One question. There are brake rotor retaining clips that hold the rotor on when new. They look like washers on one of the wheel studs holding the brake rotor on. Have these been removed? You'll want to remove them if your running aftermarket wheels.

 

After 10 years and having 20" wheels, have to think there's no way those retainers are still there.

Kind of strange you note clunk coming from the roofline, but then also mention feeling it in the steering wheel. If you have a hardtop you might just remove the freedom panel and double-check the one torx bolt above the driver's door (the front-most bolt for the rear section). I have had that bolt back out a bit before causing some noise going over bumps. If you're felling things in the steering wheel it's probably more related to either a worn joint in the steering system or just some feedback as a result of lower caster due to lift (if there is no caster correction installed). Definitely nothing caused by simply changing tire/wheel size. Probably more coincidence. This does assume the new tires are properly balanced.

 

Did the steering change drastically? What I mean is there will be some more tire sidewall flex now that you have more rubber height between road and rim but have you noticed a radical change like bump steer or play or or wandering or something like that? Is the noise there when going over bumps, decelerating/accelerating? I would start at one side rear or front of the front suspension with a small breaker bar or similar and start levering at the joints and bushings to see what has play if any. Check bolt torque as well on the Control Arms.

 

All ... sorry for going dark ... life. It turns out that it was the bolts in the driver's pillar had come loose. I had installed some grab handles a month ago, but they already came loose. It's odd the grab handles weren't loose at all, but the bolts weren't tight enough to keep the cross bar (whatever the proper name is) above the driver's head from causing my clunk. Going to grab some loc tite at some point. I installed the handles with my impact driver so didn't expect them to loosen up at all ... especially so soon.

Regarding what I was sensing in the steering wheel, there does seem to be some play in my tie rod so I'm looking to swap that and the drag link out ... time to start my jeep education. Any changes I've noticed in steering after swapping out the rims and tires are all for the better. My next mission is to diagnose the misc creeks and rattles under the jeep. It seems many of them originate from the various heat shields down there. How often should I expect to swap out bushings? I'm guessing this lift was installed soon after the original purchase and wondering life expectancy on shocks, springs, bushings etc. Much of the frame and components have a slight surface rust and I'm expecting to slowly take things apart and treat the surface ... so I might as well replace/upgrade these items as I go.