Quick question for you all. I have 1 REAR tire (driver side) cupping. What could cause this?

I noticed it after I bought the truck used. Tire was fine then, after a couple hundred km I saw this, had tire rebalanced... but still sort of doing it. Seemed ok for a while.... most driving is city, 8km a day up and down the mountain to the train station.
Just was in having brakes inspected, and asked the tire/muffler/brake mech shop their opinion. They didn't have one, no idea what could cause it. I was going to rotate to the front, but they said to not as it wouldn't be as good up there. They instead rotated it to the passenger side on the rear.

Guess I'll see how the other tire now wears or if it follows the wheel.

Any other ideas?

 

Bring it to an alignment shop that can check the front and back wheels for proper alignment. I'm not sure if a bad wheel bearing would cause that or not. Did they actually make any adjustments on the weights of that tire, was it already out of balance?

 

Cupping
Cups or scalloped dips appearing around the edge of the tread on one side or the other, almost always indicate worn (sometimes bent) suspension parts. Adjustment of wheel alignment alone will seldom cure the problem. Any worn component that connects the wheel to the car (ball joint, wheel bearing, shock absorber, springs, bushings, etc.) can cause this condition. Worn components should be replaced with new ones. The worn tire should be balanced and possibly moved to a different location on the car. Occasionally, wheels that are out of balance will wear like this, but wheel imbalance usually shows up as bald spots between the outside edges and center of the tread.

 

in addition to the above it can also be the tire itself, a belt separation will cause the tire to cup.

 

Weak shocks can let the tire bounce on the road.

 

i had a set of mud tires that all 4 of them that had like a wave pattern wear into them the front of the lug was taller than the back of the lug. my tire guy said that back shocks can cause that and cupping also. he also said once you get cupping or uneven wear you can't even it out you either have to deal with it or replace the tire

 

I believe the tire was a bit out of balance... I saw them add one at any rate. Its an aggressive tire, so some odd wear can be expected, but it seems odd to only be the 1 tire and on the rear. Now that its been swapped to the other rear position, I guess we'll see what happens. There isn't much that can go wrong on a rear axle.... a bearing or a shock. That is it. There is airbags installed on this truck, and for the first while there was no pressure in them. For the last 2 months I had 5lbs in them, not sure if that would change anything... probably not enough time has passed as I don't drive it much, and rarely at highway speeds for any length of time. Perhaps the balance and air in the bags has solved it and I just haven't drove enough to find out. I'll be taking the RV on a long trip Sept 1st (2000km round trip) so then I'll know for sure. Or I'll need a new tire...

Thanks guys.

 

I'm guessing that just before you bought it, the tire was rotated to the rear. Definitely get the front end checked out, unless of course, the rear diff could have shifted in the perches, but then you'de be drivin down the road crooked.

 

The tires were all even when I bought the truck, almost like new. This has happened while I've had it. Not saying the dealer I bought it at didn't change the tires or anything like that.... but the wear was definitely happening while the tire was in the rear driver side position since I bought it. The wear is only on the outside edges, the center is normal. Inside is worse than outside.

As said, I moved the tire over to the passenger rear side. I'll watch the tires for continued or new wear. That should give me the answer as to whether its wheel/rim/tire or position dependent. These tires were made in 07, and being on the rear they have more wear than my fronts overall (which had an 08 manufature date). I'll probably just run them off on the back and replace them in the future. There is still lots of life left if the cupping has stopped.

Thanks for the opinions.