Hey all,

I got a 2012 JKUR and new to Jeeps and 4x4 wheelin world in general.
I recently put on a TF level kit (2" front/ 1" rear) and 35s and it seems to not drive straight on speeds above 40+ mph. Steering wheel is straight but I need to constantly adjust if that makes sense. Its sometimes nerve wrecking in heavy rain because it feels i am all over the road.

I think what I am experience is called "wandering" but I also see the term "flightiness". Do these terms basically mean the same thing?

Also did a wheel alignment and got my front toe in to 20 degrees. My caster angles were like 3.1 (left) and 3.2 (right) for the front. I noticed everyone this board is stating I need 4.5 (minimum) and should go up to 6 degrees castor. Is this correct?

I am also assuming i need to buy expensive lower control arms to
get the caster angle in the prefer 4.5-6.0 degree range. Any input on this would be great!


Just figure a jeep noob would ask the experienced folks on this board on some questions!

Love mah jeep!

Thanks,

Shin0bi1

 

What you are describing sounds like what people refer to as flightiness which happens a lot after a basic lift install when stock control arms are still used. Lifting your vehicle with stock arms usually results in lowering your caster. I think factory caster is set to around 4-4.5 degrees. So your readings are a bit low...not terribly low but low. This "could" be what's giving you the flighty steering. The problem here is that it will be difficult to diagnose it 100% without increaseing your caster to see if its fixes the problems. Only ways to do that are installing a set of cheap cam bolts (which 99.99% of the people here will scream NO!!!!!!!), or getting adjustable control arms (either front upper or lower....most do lower as its easier to adjust) or looking for an alternative like the AEV drop brackets.

If/when you do try any of these, the issue becomes what is the right number. My lift company told me 4.5 degrees would be ideal for my 3.5" lift. Mine is currently at 4.4 and it drives great. Some people here will say 6 to 8 range but that is far too much for a leveling kit of your height. In fact, if you go too high, you introduce more potential driveline issues. I got a lot of vibration when I tried going to 6. I would say 4.5 degrees would be perfect.

If it's not caster, it could be a number of different things but you have to start somewhere. And caster is usually the best starting point.

 

Hey thanks for the quick response! I will look into lower control arms to correct the flightiness issue. Are these hard to install and what brand(s) do you recommend?

Thanks!

-Shin0bi1

 

I had the same issuse when I installed my lift. Seemed like you could never take your hands off the wheel or eyes off the road. I installed a set of cheap adjustable control arms. RC flex series. 150 bucks shipped. Cheapest set I could find. Anyways I dialed it in to 4.5-5 degrees of caster. Drives great now. Like night and day. My lift was a 3.5 inch if that would make any difference in caster degrees.

 

What's your tire psi? ~29psi seems to work good, & once my tires got a few miles on them it improved greatly.

 

I will look into RC control arms. Is that all I need for caster adjustment? I notice no one mentions rear control arms so is it right to assume getting front suspension stuff will fix this problem? Aslo Is there a difference between upper and lower for my needs?

And Mopar, I run between 29-32 psi on my 315/70/r17 duratracs. I do a lot of highway and don't like the feel of anything lower than 30 psi at 60+ mph.

Thanks!

 

You will want to keep your rear driveline angles neutral as well but they will not effect handling as much as the front. Also since you only gained 1 inch in the rear I would not expect it to have been comprimised much if any at all.

I would suggest evaluating what your end game is (at least for now). In some cases it is best to stick with a single manufacturer if you are piecing together chassis parts. In some cases it is perfectly fine to mix and match. From a consumer perspective there is certainly benefit to having a manufacture to go back to and ask for support on there product without mudding the water by adding other manufacture parts to the equation.

Not to say that geometry is not geometry, clearly not only can experienced individuals build a perfectly good rig out of mixed vendors "stuff" alot can do the same thing with stock plate and dom tubing its just worth considering.

I may be partial to TF, its what is on my rig and one of the many vendors whose products we sell but if a few bucks didnt make a huge difference to me i would stick with them.

Welcome to the "Jeep" world, glad to have you and hope you enjoy it as much as us!!

Just my 2 cents

 

Front upper or lower arms will do the same thing for adjusting caster. If you look at some lift kits like Rock Krawler, they will include lowers in their basic kits to dial caster in. Other kits like Full Traction will include upper arms in their basic kits. They both do the same thing but most people fid lower front arms are easier to install and adjust since you can do it with tires on the ground and with little effort.

With regards to install...if you don't have someone helping you, the best way to install lower front arms is to remove one side at a time and get the new arm in first before starting other side. Since the control arms will be longer than stock, the hardest part is getting the mounting holes on the Jeep aligned with the arm. I found having a long screwdriver on hand to pry them in made it easy.

Rear control arms will not help your steering at all. The main reason to go with adjustable control arms in the rear is to properly adjust the pinion angle on your driveshaft. 4 doors usually don't have too many issue with a stock rear driveshaft and a lift because the driveshaft is longer so any pinion change isn't usually huge. With 2 doors, the driveshaft is shorter so people could have more issues like driveline vibrations.

If you go to an aftermarket driveshaft like Coast or Tom Woods, you are usually changing the style joint to a CV style which doesn't handle angles as well so most people have to move to adjustable upper control arms in the rear to get pinion in line.

Other lift's use rear adjustables to push the axle back to re-center the wheels after being lifted. My X-Factor from Rock Krawler, for instance, does this where the entuire axle gets pushed back 1" which helps re-align the wheel to the center of the wheel well and help reduce potential rubbing on pinch seems and other parts when moving to bigger tires.

OK...long explanantion but for you, adjustable front lowers are all you need. And then keep your fingers crossed that it fixes the problem!!

 

Loosen up the lower control arms/trackbars, rock your JK back and forth while it's on the ground. Then retorque. You do not need adjustable control arms/ drop brackets or cam bolts for this kit. Typically flightiness is from bound up control arm bushings.

 

^^^^^^^ Yeah...this too!

Sorry...I assumed you already did this when you installed your leveling kit...