Tire Cupping/ Causes?

[bigfoot21075]

For what it's worth cupped tires is almost always a shock issue. The shock's job is to not only absorb the initial impact, but to also help the tire rebound back onto the road surface.

A worn shock may absorb the impact fine enough but not have enough stiffness to properly rebound it. If you're running 28 psi there's a very real chance you haven't noticed the worn shocks due to the tires themselves absorbing a significant amount of road impacts.

Replace your shocks. They last maybe 40k-60k miles at most, especially with larger tires. Just because they aren't leaking doesn't mean they aren't worn.

I agree, that is often the cause, however it is clearly not the shocks in this case. it easily passes the bounce test, the Fox shocks only have 24k on them.

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[alphawolff]

I agree, that is often the cause, however it is clearly not the shocks in this case. it easily passes the bounce test, the Fox shocks only have 24k on them.

The bounce test was really designed for a normal sedan or sports car even. I know it's old gear head theory but it really doesn't apply that well to wranglers, especially ones running oversized tires. I used to think the same thing a few years ago until I saw the evidence first hand on old my 2012 sport. 60k miles on the stock shocks and bounce tested fine, but new shocks were a night and day difference. I changed them on a whim and couldn't believe the difference. Same OEM shock, too.

I've seen shocks wear out in as little as 20k miles before, so you're still in that ballpark. I'd still strongly suggest looking into it if your new tires end up cupping as well. It's also possible your fox shocks aren't rated for your setup as well. Fox has a really large amount of options these days. I know 37s look amazing on a wrangler but they are *large as hell* and are difficult for the suspension to properly handle.

 

[bigfoot21075]

The bounce test was really designed for a normal sedan or sports car even. I know it's old gear head theory but it really doesn't apply that well to wranglers, especially ones running oversized tires. I used to think the same thing a few years ago until I saw the evidence first hand on old my 2012 sport. 60k miles on the stock shocks and bounce tested fine, but new shocks were a night and day difference. I changed them on a whim and couldn't believe the difference. Same OEM shock, too.

I've seen shocks wear out in as little as 20k miles before, so you're still in that ballpark. I'd still strongly suggest looking into it if your new tires end up cupping as well. It's also possible your fox shocks aren't rated for your setup as well. Fox has a really large amount of options these days. I know 37s look amazing on a wrangler but they are *large as hell* and are difficult for the suspension to properly handle.

Oh 100% FOR SURE. I will be watching these tires like crazy. I would think these shocks are more prone to wear given the VERY soft spring rates of the Metal Cloak suspension. I can stand next to it and push on the top with one finger and easily move it side to side compared to other lifted Jeeps. Makes it great for going over obstacles but a bit more of a handful on the highway. As good as this suspension is for off road, I would not buy another one.

I APPRECIATE the input for sure... from everyone!

 

[Ratbert]

I am not replacing the unused spare and will not be able to rotate it in. i am OK with that.

As you're aware: your cupping would be ~20% less if you'd rotated the spare in.

 

[bigfoot21075]

Yes, 100% so - but I am still not buying another $435.00 tire to do it. It does not add up in the end for an extra 9,000 miles. the cupping is a problem and should be next to zero. The combo of too low psi and cheap M/T tires along with not enough rotation is likely the issue

 

[beaups]

I have the full MetalCloak 2.5" GameChanger Suspension. I thought they replaced the stock ball joints with their Duroflex™ Joints

I rotate every 7500, but have always used that interval. i have to wonder if it is these tires. They also suffer from "radial draw".

Just to continue being a pest, FWIW the “Duraflex Joints” that come with that kit are not referring to ball joints.

The shitty stock ball joints fail in such a way they seem “tight”. You cannot really tell they failed until you tear everything down. There are a few threads on this.

 

[bigfoot21075]

Just to continue being a pest, FWIW the “Duraflex Joints” that come with that kit are not referring to ball joints.

The shitty stock ball joints fail in such a way they seem “tight”. You cannot really tell they failed until you tear everything down. There are a few threads on this.

First off, it is NOT being a pest trying to HELP me get the most out of my Jeep! It is TRULY APPRECIATED!!! THANKS!

Second, yes i know the Duraflex are not ball joints. I will probably get a set of Moog or the like in the next few weeks just to head the problem off at the pass. That is a pretty easy job I have done many times on many different vehicles. I will break out my air hammer pickle fork and have a good ole time! . I have a list of things to knock out on my vacation like my winch install, aux switch panel and possibly a 2024 grill.

 

[jeep_from_downunder]

Have an appointment June 14 to get 4 new BFG All-Terrain T/A KO2 's. Looks like they will be $435 a piece plus $29.00 mount and balance

4 of my BFGoodrich KO2 AT tires are cupping and the noise are so loud. My JLU has done 45000km (I'm from Australia). I have booked my Jeep in with the dealer to get the suspension checked out. But I do notice some squeaking noise at the rear suspension.

 

[bigfoot21075]

4 of my BFGoodrich KO2 AT tires are cupping and the noise are so loud. My JLU has done 45000km (I'm from Australia). I have booked my Jeep in with the dealer to get the suspension checked out. But I do notice some squeaking noise at the rear suspension.

Hope you can get that straightened out!!

 

[roaniecowpony]

A few years ago, I was having related issues and started researching causes. I had a stock suspension at the time. After reading as much as I could find specifically on JL Wrangler balljoints, I bit the bullet and bought the Dynatrac balljoints. Some of the testimonials included experiences with other brands of less expensive balljoints, where they had experienced short life. Specifically, I followed the experiences of @wibornz who has more miles on and off road in his JL than any other JL owner I could find. He recommended Dynatrac after trying Dana, IIRC.

As a reference, I have been using Moog suspension components in my other vehicles for decades, most recently in my GMC pickup. I have come to accept that the Jeep JL has something unique about the design that is particularly hard on the balljoints. My assessment is that they are undersize for their job, especially with 33" and up tires. Dynatrac balljoints bring high quality tool steels into the equation to improve life. They are the "gold standard" in JL balljoints at this time. The new Metalcloak balljoint also looks to have included some of the same features as the Dynatrac. It's a lot of money for either of those two, for a guy like me that's used to a $35 Moog balljoint. But I'm very pleased after a year or so of wheeling around the southwest. Place your bet on the balljoints you think will work for you.

 

[wibornz]

A few years ago, I was having related issues and started researching causes. I had a stock suspension at the time. After reading as much as I could find specifically on JL Wrangler balljoints, I bit the bullet and bought the Dynatrac balljoints. Some of the testimonials included experiences with other brands of less expensive balljoints, where they had experienced short life. Specifically, I followed the experiences of @wibornz who has more miles on and off road in his JL than any other JL owner I could find. He recommended Dynatrac after trying Dana, IIRC.

As a reference, I have been using Moog suspension components in my other vehicles for decades, most recently in my GMC pickup. I have come to accept that the Jeep JL has something unique about the design that is particularly hard on the balljoints. My assessment is that they are undersize for their job, especially with 33" and up tires. Dynatrac balljoints bring high quality tool steels into the equation to improve life. They are the "gold standard" in JL balljoints at this time. The new Metalcloak balljoint also looks to have included some of the same features as the Dynatrac. It's a lot of money for either of those two, for a guy like me that's used to a $35 Moog balljoint. But I'm very pleased after a year or so of wheeling around the southwest. Place your bet on the balljoints you think will work for you.

Sometimes you just have to buy better. The Dynatrac ball joints are worth it in the extended life of the ball joints and the ease of rebuilding them . They just handle the harsh environment of off-roading better.

 

[bigfoot21075]

For my education, "cupping" means the center is worn out before the edges? If yes, wouldn't that happen because of over inflation?

No not exactly, what you describe is under inflation wear. Cupping is where the tire has dents in it.

 

[Ratbert]

No not exactly, what you describe is under inflation wear. Cupping is where the tire has dents in it.

Correction: overinflation.

 

[jeep_from_downunder]

I got my suspension checked out by Jeep yesterday and they told me all four of my shocks need replacing. My Wrangler is still under warranty so there will be no charge. But still disappointed that the tyres are cupping caused by bad shocks.

What is the average life on a shock? My Wrangler has only done 46000km so far.

 

[SaintNick]

I personally could never wait 6000 miles. I have always done the a 5 tire rotation every 3-4000 miles. that schedule has served me well on my last 5 jeeps.

Yes. Rotate oversized or MT tires every 3K miles. Might be able to go longer with a KO2.

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