vwhitlow

So my front tires are cupping and I don't know why or what to do about it? I have 38000 miles on my Jeep and have 235/85x16 tires on it. Please reply with any help to solve this problem.
Thanks

Mitch1196

Have you done a chalk test to ensure you are running the proper air pressure in the tire?

shabbernigdo

How often do you rotate them? do you check the pressure often?

larry0071

The first thing I would think is that your not rotating every oil change and have Rubicon/Willys MT tires. You have to be proactive about rotating them to keep them even. Air pressure doesn't typically cause cutting/cupping, it will cause center or side wear.

Blue

The Rubicon/Willys MT tires would be 255/75/17's.

tarpon4me

Sounds like it's time to upgrade to 35's. And once you do that, keep the tires rotated every oil change and run the PSI around 30 and you're golden.

mr72

That center/side wear will only matter if you are WAY outside the recommended pressure. If you are +/- 10psi then the tires will wear evenly.

But it doesn't matter. Cupping is probably caused by bent/worn suspension parts, which is entirely possible at 38K on a Wrangler. Or it could be caused by poor alignment, excessive toe out. Rotating the tires may mask it by moving the problem to a different axle where it will wear off the cupping but it won't solve it.

rob_engineer

There is nothing wrong other than you haven't been rotating enough. Put the cupped tires to the rear. All will be well again. MT tires on our jeeps can get cupped on the front without it being an indication that something is wrong. I saw cupping on mine around 18,000 miles. I was shocked and posted on here about it. I learned it was basically normal. I rotated to back and all was fine for another 15k or so.

mr72

100% disagree. It may be common, but it's not normal.

And that's my point, if you see cupping, then rotating the tires on a shorter interval can make the cupping less evident because you move the tire to the other axle before the cupping gets severe enough for you to see it, but you haven't fixed the problem that is causing the cupping to begin with.

Now, it may be endemic to the design of the suspension. It may be at least partly due to poor QC at Jeep, or extremely wide manufacturing tolerances--I have seen this a bunch on other cars. And it may be that whatever problem is cannot be repaired or adjusted out without a complete overhaul of the suspension, but that doesn't mean it's normal.

By all means, rotate the tires more frequently if you don't want to deal with cupping. It is accelerating the tire wear whether you know it or not, and it is reducing what is already horrible on-road handling performance by running the cupped tires even if the cupping is never allowed to get so severe that you see it before you move the tire to the other axle.

IMHO.

rob_engineer

I put new rubicon take offs on my 2012 when the jeep had 1000 miles on it. At mile 18,000 I had significant cupping. Fast forward a few years and I put duratracs on at 50,000 miles. I have just rotated my duratracs after putting 20,000 miles on them. There is no sign of cupping. This tells me that the design of the tire plays a large role. The Goodrich MTs from the 2012 era certainly got cupped. A coworker had the same experience as me with those tires.