So I just bought a 2010 JKU Saharacon...lol Sahara with Rubicon axles 5.38 gears, lockers, 4" RC X Series lift 35 12.5 20 Nitto Trail Grapplers on Trail Ready not really bead lock wheels. Pretty happy with the Jeep but the handling on the highway above 60mph or so is real darty. I set the toe in to about 1/8, the caster is just shy of 5 deg according to my angle finder, and the previous owner installed an axle mounted track bar relocation bracket without doing anything with the draglink so there is some bump steer.

Aside from a few potential alignment issues, do the 20 inch wheels handle poorly on these Jeeps or is there an opinion about that? I had an 06 Mustang that we went from 18 to 20 inch wheels and never got it to handle right again.....just curious on this.

Thanks for the input.

 

Not exactly sure on the wheel size question - a 35" tire is definitely not going to feel great on a 20" wheel though. Regarding feeling a bit uneasy I personally suggest you try a Fox ATS stabilizer - I think it will minimize your issue. I never really felt any difference using a stabilizer before and for a while even ran without one. It was fine but definitely didn't feel close to factory and I did feel bump steer or uneasy on cornering at higher speeds. Many people will argue and say "you don't need one, check your alignment and blah blah blah" but my alignment was perfect and although I didn't "need one", running my ATS is killer. I can hit anything with two fingers on the wheel and she stays perfectly straight...corner faster and it feels more stable. In general just so much tighter...even better than factory.

 

Thanks for the response. Funny thing, the jeep is good cornering it is trying to drive a straight line that is un-nerving and the faster you go the worse it seems to get. Actually, I have a 5" lifted CJ7 with lockers and 35's and I am far more comfortable at 75 in it than I am in the new JK and frankly that seems VERY wrong to me.

 

Do you find it's pulling you in any specific direction (e.g. Always to the left) or is it a bit all over the place?

 

If it is darty on the highway at speed i would first look to see what your pinion angle is. Mine was that way when I first lifted it,, then measured the front pinion at 2.2 deg,,,, adjusted to 4.6 deg and the diff was enormous!!! totally planted feel after the adjustment.

 

Where did you take the pinion angle measurement from? Are you sure you aren't talking about caster...only ask because 4.6 is close to the caster recommendation.


There is no distinct pull left or right just darty. Some of it is bump steer I think but at speed it is hard to decifer what is what.

 

Just throwing it out there. Stock ball joints are know to be weak. Stock control arm and track bar bolts are know to be to narrow and allow movement?