Cupped tires- what are the real symptoms?

[Larry Phillips]

How would I be able to diagnose a cupped tire, or more accurately, my vibration issue?



My symptoms include a vibration that varies with speed, and an associated sound, it sounds and feels like there's a rough patch on my tire. Right now, I can't even figure out which tire it is, though I think it's on the driver's side. When I'm going slow through a parking lot, I can feel a slight yet rough vibration in intervals. This is the second set of tires to do this. The first set were Kumho Ecsta STX tires, and now on my Hankook Ventus ST tires. Both are 285/60R17



I was thinking based on what it feels and sounds like, that the cause of the odd wear could possibly either a bent rear axle shaft (bent near the end where the lugs are) or a slightly bent rim, or an alignment problem, but I don't really think it's the alignment. I do bottom out a bit more than the average ST since I'm running on 3 inch drop blocks.



Any ideas?

 

[Hal S]

Cupping usually occurs on the inner edges and can be felt as alternating high and low spots on the tread just by moving your hand around the inner edge.

Most common cause is lack of correct rotation pattern combined with some degree of misalignment.

 

[Jim P]

worn shocks can also lead to cupping as the tire/wheel bounces too much, and does not stay in constant contact with the road surface, alignment is another cause, does the cupping happen only the front tires?? I had some A/T tires on my 03 when i bought it, and they sounded like the front bearings were totally shot, but new tires eliminated all of the noise. Might just be bad tires

 

[Axel Deneselya]

the two previous posts pere pretty dead on. the only thing I would add would be worn ball joints. they are a relativly cheap fix if that is the culprit. good luck.

 

[Wes Davis]

The cupped tire(s) will be obvious. It is plainly visible. Check the inner edge of your tire treads and you will see a wavy pattern on the cupped tires. Once it reaches the point of being felt inside the car you will have no problem seeing the cupping. On our Sport Tracs the common cause and cure is the shocks. Replace with new upgrades. If your tires are expensive you may be able to save them by getting new shocks and rotating the tires. The new shocks will cause the cupped tires to begin wearing evenly and the noise or vibrations will go away over time.

 

[Johnny O]

Causes:

1. Shocks.

2. Alignment.

3. Other worn suspension parts.

Tires that are not rotated will wear funny but that in itself will not cause cupping unless there are already other problems.

 

[Larry Phillips]

Ah, I didn't even think about my ball joints, they do need replacing. Thanks for the replies.

 

[Thomas Rogers]

Causes:



1. Ford

2. Ford

3. Ford







Okay, to be fair, the reasons I got cupped tires seemed to be:



1. Bad OEM tires...Ford's fault.



2. Bad OEM shocks...Ford's fault.



3. Bad Alignment...Ford's fault (the service rep told me that no amount of aligning of the Explorers ever gets them into perfect alignment, that they simply have too much slop to them).

 

[Lester Durst]

Had "the cupping problem" onthe wifes '02 S/T. Installed new tires and shocks that were recommended on this site. Havent seen any sign of "the cupping problem" reoccuring since and that been 20k miles ago.



I'ld have to say the undersized OEM shocks are "problem".