JLUR - right rear tire offset?

[xeon]

The question is..... are there any other JL owners that have this odd characteristic where the rear right wheel is 1/2" further out than the left rear wheel?

I picked up my new JLUR on 4/21 and now with over 2000 miles I am used to the twitchy driving characteristics ("the wiggles") it gets when at speeds over 50 mph. I have taken the it back to the dealer to check alignment, tire balance, etc..... no changes and they swear it drives like all the other JLURs out there. I have the mopar 2" lift along with 35" BF KO 35" x 12.5. With all this said....I have noticed that the right rear wheel sticks out further from the fender than the left side. I thought my eyes were deceiving me but after measuring its exactly 1/2" further out that than the left side. The front tires are even under the fender. I have measured fenders to make sure one set was not narrow and they are fine. Checked tire widths in case the new tires were same...and they are equally 10" of tread on each and 12.5 over all.

I am wondering if this offset is contributing to the "wiggles". The next question is do I need to worry about 1/2" of offset.... I rather have the tire under the fender more. I haven't taken off the rims and measured those yet...thats the next step. Just wondering if its just me or if others have this issue too. Not to many JLs out there for me to look at and compare.

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[Jkohler]

Sounds like you need a adjustable track bar to bring the rear back to center

 

[xeon]

Rear adjustable track bar. Seems pretty reasonable for cost but wondering why a new JLUR would be that far off? Great option for a fix....thank you.

 

[xeon]

Here is are some pictures of the issue. Measured from rear door sill 1ft to center an iPhone leading edge.

 

[Jkohler]

it happens with lift kits. You are changing the factory geometry. Most the bigger kits come with adjustable bars.

 

[xeon]

From everything I am reading the track bar is the solution. I am wondering why the Mopar 2" kit didn't come with one. Since I am new to jeeps and lifting them as well. I am guessing I should get two ... one front and one rear? Would you have any recommendations for good track bar? Thank you again for your help.

 

[Jkohler]

Rough country has one out for the front but not the rear at this point. I'm not sure who is selling the rear by itself at this point.

 

[xeon]

Thank you for the insight...I will been my quest there..

 

[Rusty Teeth]

That is really odd, can you see if its the rotor, wheel offset tire. Just looked on my jlu sahara, similar tread. I can see same raised print on inside of tire. Does not seem the tires are directional. Yet the tread looks like it should be. Will look at the dealer and measure one on sales floor.

 

[xeon]

Oh my... didn't even see the subtle difference in tread pattern until you brought it up...sure looks unidirectional. The tire with the offset is the passenger rear. Not sure what you mean by "see if its the rotor, wheel offset tire". Going to pull off the wheel and see what I can find.

 

[Pressurized]

I'll try to put some clarity to this discussion. On a track bar or panhard bar suspension, the axle does NOT move in a linear up and down motion, it actually swings on an arc that is controlled by the track bar. The fulcrum point is where the bar mounts to the frame. In the rear the frame mount is on the passenger side. So as you lift, the axle swings out to the passenger side. It should be noted that this happens during any suspension movement too, while you are driving. As the suspension extends, the entire axle moves out to the passenger side and as it compresses, it moves towards the drivers side.

The front axle has the same characteristics, it just moves the opposite way since the fulcrum point is on the drivers side so when the suspension extends, it moves the axle to the drivers side. Axle shift is not a cause of driveability issues.

The new rear axle in the JL already has a high track bar mount for proper roll center. On the JK's, we added a rear track bar bracket to raise the roll center which also meant that the stock track bar would still be very close to centering the axle. Raising the roll center gets it closer to the COG which reduces body roll when cornering. On the JL, there is no need for roll center correction, so no bracket is included. So now when you lift it 2" in the rear, the axle shifts about 1/2" making it stick out on the passenger side about 1" farther than the drivers side.

The same is happening in the front, just to the drivers side... On a JK it was common to be able to keep the stock rear track bar and add an adjustable front bar and you were good. On the JL, if you want to be centered (my OCD says yes, it must be fixed) on both, it will likely require adjustable track bars front and rear.

One thing that rings true on the JL, just as it has on every other Jeep, is that all Jeeps are a little different. I have already seen 3 JL's with the Mopar kit that had opposite effects. One had the rear axle out but the front was still very centered, another had the rear that looked great and the front needed correction and the last one had both out and needed both bars to correct.

The million dollar question? Why aren't they included in the lift kit? Every manufacturer builds a kit to hit a certain price point... I'd say that Mopar didn't think the extra $400 was going to look good on the price tag.

 

[Pressurized]

For what it's worth, Rock Krawler is showing their rear adjustable JL track bar in stock.

http://www.rockkrawler.com/ProductDetails.asp?ProductCode=RK06692

 

[xeon]

Fantastic write up. Explained what I was just not understanding so thank you. With respect to the big question of why MOPAR did not address this issue, given the cost difference of $400, is just insane. Am I going to spend $400 to get the geometry right...of course I am. So why would they not included it. Makes no sense. At this point I am thinking they didn't spend much time engineering the MOPAR Lift - bowing springs and now we need two adjustable track bars.....something tells me we might need something else soon. At least I know there is a simple fix in my future. Thank you

 

[Rusty Teeth]

I gather the wheel is not plum or no longer 90 to road as it moves in an arc. Per illustration

Need get a bubble on that

 

[Pressurized]

I gather the wheel is not plum or no longer 90 to road as it moves in an arc. Per illustration

Need get a bubble on that

The wheels are perpendicular to the axle and the axle stays parallel to the ground, so all of that geometry stays in line appropriately. While the axle does travel in an arc, there is a pivot point at the axle that allows it to stay parallel with the road surface.

Cheers!

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