Tire wear question

[Sal-XK]

I rotated my tires today and as usual I did my inspection. My tires have about 20K on them now and have been wearing down perfectly even. Today I noticed my passenger side rear tire tread was uneven. It wore obviously more on the out side then it did on the inside. The inside nobs were visually much higher. Any ideas on what would cause that to happen? I rotate my tries every 6k I just move the front to the back no crisscrossing. When I moved it back there it was all even so I'm lost now at what could cause this in the rear. I do know my shock wasn't seated properly for some time but can't see how that caused it. Any ideas would be great I told the wife I might need the adjustable track bar now LOL

[Matt]

That's a strange one man... so within 6k miles the outer edge of the RR tire wore more than the inner edge?

Honestly, unless your having some other symptoms, i'd say it was just due to offroading.

[Sal-XK]

Thats probably it I was spinning my tires a lot on those rocks. It should just wear back down without causing problems I'm guessing?

[Matt]

Yeah you should be good.

I would start doing a cross rotation though:
Backs straight to the front
Fronts cross to the rear

[cico7]

Check your alignment. Sounds like the camber may be off

https://theultimatejeep.com/images/imported/2011/12/camberwearJPG-1.jpg

https://theultimatejeep.com/images/imported/2011/12/TireRot2-1.jpg

https://theultimatejeep.com/images/imported/2011/12/TireRot3-1.jpg

Tire Care (http://theserviceadvisor.com/tire-care.shtml)

[Matt]

Theres no camber adjustment on the rear tires.

If it was the front tire, the 100% alignment.... but:

Today I noticed my passenger side rear tire tread was uneven. It wore obviously more on the out side then it did on the inside..... When I moved it back there it was all even so I'm lost now at what could cause this in the rear.

[Sal-XK]

I didn't notice anything unusual when I rotated the tire to the rear. I thought the tire rotation for all wheel drive was just front to rear? So your saying I was suppose to be crisscrossing just the front to the rear and move the rear straight up?

[Matt]

Yeah, you should be crossing the fronts when you bring them to the rear. The front tires get feathered from taking the loads while turning whereas the rear tires are just "following" the fronts. When you cross them to the rear it smooths out any feathering caused from being on the front.

[Sal-XK]

Ok I'll give that a try in about 6k miles :)

[criket]

I agree with Matt. Try the crossing thing and see how that goes. Can't hurt that's for sure.

You speak of the track bar to bring the rear axle back to center. I know mine is off about an inch maybe??? I wonder if the rear axle being off caused the tire to wear like so because of weight distribution? I know you carry a lot of stuff in the back so could the weight have more pressure on the inside part of the tire b/c the rear axle was shifted to one side some? Probably not....IDK.

[Matt]

https://theultimatejeep.com/images/imported/2011/12/tire_rotation_abc-1.jpg

I personally recommend the rearward cross for lifted 4x4 vehicles, especially ones like ours that are hard to keep the alignment within spec due to the types of lifts we run.

The rearward cross is the best at mitigating tire wear associated with alignments that are at the edge of their spec range by putting each tire at every point on the vehicle. So say your right-front camber is a bit off, well with the rearward cross a tire will only see that position 25% of the time whereas if you go with the x-pattern it will be there 50% of the time.

[Sal-XK]

I used the tire wear as an excuse to say I needed the track bar LOL

[cico7]

I missed that it was rear tire, but if you cross, you put the inside sidewall on the outside.
If you have blackwall tires, may not be an issue. If one side is whitewall you will look funny......

[Matt]

I missed that it was rear tire, but if you cross, you put the inside sidewall on the outside.


lol... brain fart?

The outside tread is always the outside tread regardless of where you mount the tire on the vehicle.

The only way to change this is to dismount the tire and flip it over on the wheel

Edit: think about it.. does that mean if you cross the tires then you'll see the back of the wheel instead of the front? :p

[Matt]

I used the tire wear as an excuse to say I needed the track bar LOL

It's not beyond possible man. Not from a load standpoint as much as a crab-walk standpoint. If the axle is being pulled too far to the driver side then the rear will try shifting back to the passenger side as you're driving to following the front (basically the vehicle always tries to "square" itself). Did the driver side tire wear more on the inner tread? (that would indicate the axle is trying to shift right while driving)

... i just don't see that being enough of an issue on these vehicles to cause noticeable wear after only 6k miles. Spinning the main drive tire (RR) on rocks while offroading seems a lot more probable to me.

BUT.. it's better safe than sorry, so i recommend you get that adjustable track bar *wink wink*

[Sal-XK]

Nope all three other tires looked great as usual. Like I said these tires have been wearing perfectly even the entire time. So I'll go with off road damage on this one but the track bar is needed to fix the problem LOL

[Matt]

The track bar being too short limits proper flex and accelerates the offroad wear... (sounds good! order up that fix)

[Sal-XK]

It's rough country that makes the track bar?

[Matt]

http://www.rocky-road.com/grandtrack.html


Our Rear track bar for the WK Grand Cherokee (2005 and newer) gives you fine tune adjustability for your rear axle on lift at or over 2.5".

[NeilSmith]

Ive always done the rearward cross every 6K and they are wearing wonderfully. Id say its from spinning em while wheeling. There is no camber adjustment in the rear and you say you didnt see the problem when it was moved from the front. Cross em up and see if it changes next time.

[criket]

I thought Rusty's had a JKS track bar that worked too?

[cico7]

No Matt, if you rotate the wheel, you change the direction of rotation. If you have directional tires,
you change the flow of the tread. Originally, you had to keep radial tires going the same way.
That is no longer true. Directional tires are still built to rotate one way.


lol... brain fart?The outside tread is always the outside tread regardless of where you mount the tire on the vehicle.The only way to change this is to dismount the tire and flip it over on the wheel
Edit: think about it.. does that mean if you cross the tires then you'll see the back of the wheel instead of the front? :p

[Sal-XK]

I thought Rusty's had a JKS track bar that worked too?

That's who I was thinking of. They made a track bar for there 4" lift.


No Matt, if you rotate the wheel, you change the direction of rotation. If you have directional tires,
you change the flow of the tread. Originally, you had to keep radial tires going the same way.
That is no longer true. Directional tires are still built to rotate one way.

I see so my taking the front right and putting it to the left rear your changing which direction the tire spins in. I'm guessing my tires are directional tires do to the tread pattern I'll have to look.

[Sal-XK]

I'm pretty sure someone here ordered the rusty's track bar one of the WK guys I think.

[hoaxci5]

I think Nathan (Omelet) has one.

[Matt]

No Matt, if you rotate the wheel, you change the direction of rotation. If you have directional tires,
you change the flow of the tread. Originally, you had to keep radial tires going the same way.
That is no longer true. Directional tires are still built to rotate one way.

You misunderstood what I said. Your post made it seem like you thought the inside tread (or inner sidewall) of the tire would be on the outside if you crossed the rotation which isn't true..... the inside of the tire stays on the inside regardless of where you mount it on the vehicle. So having whitewall mounted "inside" doesn't even matter, you'll never see.

Sure, the direction of rotation changes, but the inner tread is still on the inside of the vehicle.

[cico7]

...I see so my taking the front right and putting it to the left rear your changing which direction the tire spins in. I'm guessing my tires are directional tires do to the tread pattern I'll have to look.
If you dismount the tire and turn it around you can keep the same direction;however,
you would have the other side of the tire on the outside.
Back to you Matt-

[Matt]

So you're talking about dismounting the tires from the rim, flipping them over and then rotating them?

When you said this;

I missed that it was rear tire, but if you cross, you put the inside sidewall on the outside.
If you have blackwall tires, may not be an issue. If one side is whitewall you will look funny......

I thought you were talking about just doing a normal cross rotation....

If you don't dismount the tires from the wheels, the inside tread always stays on the inside. If you dismount and flip the tire on the wheel, obviously the inside tread goes to the outside. I just didn't realize that's what you were talking about doing.

[cico7]

So you're talking about dismounting the tires from the rim, flipping them over and then rotating them?
When you said this;
I thought you were talking about just doing a normal cross rotation....
If you don't dismount the tires from the wheels, the inside tread always stays on the inside. If you dismount and flip the tire on the wheel, obviously the inside tread goes to the outside. I just didn't realize that's what you were talking about doing.
Yes, I am talking about maintaining the rotation of the tire on a cross swap.
.

[Matt]

Ah. Well that explains it. :)

If you have directional tread id just do a front to rear rotation then. One of the benefits of cross rotation is changing the direction of rotation, which you obviously can't do with directional tires. It wouldn't be worth it, IMO, to dismount & rebalance all the tires every 5-6k.

[07JeepXK]

I used to do the rearward cross (rear tires straight to the front, front tires cross to the rear) robby had told me to do that when I had some weird cupping issues with my last set of MTR's. I did that for a while and my tires were still getting messed up. For the last several tire rotations I have just been rotating front to rear and keeping them on the same side of the vehicle and noticed the tires are wearing so much better. I do need the JBA UCA's though hoping they will fix my alignment issues up front. No one can get the front end into spec due to the lift so the outside of both front tires wear faster then the rest of the tire. I rotate my tires ever 1,500 and it helps a lot. Doesnt take me more then 20 minutes to rotate them with the air compressor!