Tire Cupping and Front Wheel Alignment

[gordonsick]

Normally I park my Berk with the front wheels pointing ahead, but I recently had to maneuver at a fuel stop and left my front wheels pointing to the right. For the first time I noticed that the inside rib of each front tire was cupping and wearing heavily. Obviously, it needs a front wheel alignment at 35,000 km (22,000 mi). I've never snagged the front wheels on anything, so it must have been this way from the factory. My local Goodyear dealer (Fountain Tire) says that they see a lot of vehicles from the factory that aren't aligned.

I think I'll opt for a new pair of Goodyear front tires. I'm tempted to go with Michelin, but the dealer says he can get better pricing on Goodyear, because I already have Goodyears on. He claims that Goodyear does a bit of an adjustment in the price.

This seems like an obvious topic, but I think it is worth posting because I am surprised at how I got caught out on it. I'm sure it will lead to a bunch of subsequent posts from people saying that I'm a fool, incompetent or a dangerous RV owner. I'm not, so some of you might get caught like me, even though are diligent about your care and maintenance.

I've often been under the front end of my RV: servicing the generator, greasing the suspension, draining the air lines and checking the tire pressure. But, I've never done this with the wheels turned, so I never noticed the cupping. The inside ribs were always poorly lit.

Moral of the story: when you decide to clear the water from your air lines every month or so, turn the front wheels to make the job easier. And, have a good look at your tires.

–Gordon

[zuckerburg]

Gordon GY has had a bunch of issues with their tires doing exactly this. I know several people have had the same issue. I believe Paul had GY pay for new tires on his. Check with him. Also when you get a front end alignment have them give you the paperwork on how far it was out. This show give you the ammunition to get GY to stand behind the tires.

[gordonsick]

Originally Posted by zuckerburg

Gordon GY has had a bunch of issues with their tires doing exactly this. I know several people have had the same issue. I believe Paul had GY pay for new tires on his. Check with him. Also when you get a front end alignment have them give you the paperwork on how far it was out. This show give you the ammunition to get GY to stand behind the tires.

That's interesting. Who is Paul?
–Gordon

[Mmnsc]

Gordon
Good Year has a problem with tires on Motor Home wearing out on the edges. They call it "rivering". Check with TMMAR who has had the problem and also has had alignment done. Tom should be able to tell you what he knows about the condition and any remedy.

[padcarroll]

I recently discovered the same thing on a Legacy. I had a front end alignment done and the tires rotated to the inside rear. I was told that this condition is caused because the original alignment was probably done with a empty coach. A loaded coach requires different adjustments than an empty coach.

[mikey]

Gordon, besides looking at alignment your shocks are probably worn out as well. Cupping is generally a shock issue, so change to a quality (Koni or Bilstein) shock to solve your problem. Your worn tires won't heal themselves so they need to be addressed soon. If cupped badly enough, they won't make it to the change date based on the date code on each tire. If you elect to continue them in service, a steering stabilizer would be in order (Safe-T-Plus) to assist in the event of a front blowout!

Travel safe, enjoy your journeys

[jcowles3]

Be sure to check alignment of the rear tires as mine was 1/2" off so no matter what I did front tires would get chewed up... I get my rig aligned every now and again as $200 is way cheaper than new tires. And yes once the ware pattern is on a tire it will never stop. I also have rivering on 2 tires...

[zuckerburg]

Not much they can do on the rear alignment. I was told that would require grinding the welds out and re-welding.

[Mmnsc]

When I had my new XLT aligned the tag was out of alignment. FL straightened it out and gave me the spec sheet before and after.

How come there does do not seem to be reports of tire cupping or rivering on Berks with Michelin tires. The problem is with Good Year tires.

[gordonsick]

Good news. I just got back from picking up my Berk at Fountain Tire, which is the Goodyear franchise in our area. They installed 2 new front tires G670RV 255-70R22.5 with a value of C$1496 for no cost. I paid for the alignment, balancing and installation, which came to C$322.76. That includes 5% sales tax and a tire recycling fee of C$18.

I was pretty pleased, of course.

The alignment was out, but I guess the Goodyear rep (who did come to the shop to look at the tires), concluded that the tires were substantially at fault. The total toe-out was 0.22°, where the acceptable range is 0.03° to 0.15°.

The rear axle is also out with a Thrust Angle of 0.4°, where the specified range is -0.04° to 0.04°. As someone noted in an earlier post, these rear axle settings are welded on, so they can't be changed. I guess the MH will always drive with a slight skew. I'm not as worried about that as I am with the toe out problem.

My MH has 35,000 km (21,748 mi) on it.

–Gordon

[gordonsick]

In my investigation of my Goodyear tire wear problem, I learn that it is called "Rivering". It involves heavy wear and cupping on the innermost or outermost tire rib (or the one next to it).

But, I also found that Michelin has a problem that they call a "Zipper", which is a surface separation of the rubber at the interface of the sidewall and the tread.

So, both manufacturers have a problem with RV tires at the approximate point where the belt that runs next to the road meets up with the radial plys. This must be a difficult design problem, because both tire manufacturers know what they are doing.

It would be interesting to see whether there is a higher incidence of rivering on Goodyears than zippering on the Michelins. Since FR is switching their production from Goodyear to Michelin, it looks like this forum will have future postings describing both problems.

–cheers, Gordon

[zuckerburg]

FR doesn't spec the tire brand. Freightliner had awarded GY their tire Contract several years ago but failed to keep up with production. FL at that time nullified the contract and went back to Michelins. A good move in my opinion.

[zuckerburg]

Glad that you were able to get the tires replaced. My 2011 is also out of alignment on the rear. I forget the exact amount. It wasn't enough to warrant the amount of work to make it straight. I keep an eye on my tires because of that.

[gordonsick]

Looking more carefully at the before- and after-figures for toe on my Berk, they are all positive. After alignment, they are less positive, but still positive. The specified range for toe is 0.2° to 0.8°, which is also positive.

I always thought that a vehicle would be set to have a slight toe-in for better stability, so it must mean that a positive toe number is for toe-in, since the spec calls for a positive number. I checked this in Wikipedia and it confirms that a positive toe figure is toe-in. https://en.wikipedia.org/wiki/Toe_(automotive)

Now, my tires were rivering on the inside rib, which is consistent with toe-out, not the toe-in that I had before and after alignment.

This is probably why Goodyear provided me with a free set of front tires. The wear pattern couldn't be explained by mis-alignment. This might explain why some people get a concession for the tire and some don't.

–Gordon

[dan-nickie]

Just noticed it on my front tires also. I need to find some kind of Tire shop to take it to. But I'm not sure what kind of shop to search for?

[gordonsick]

Dan,
My Freightliner shop recommended that I go to Fountain Tire, which is the major Goodyear dealer here. The first Fountain Tire franchise that I went to couldn't handle truck tires and chassis, so they sent me to an industrial one with the same owner.
The important issue is to get a suitable Goodyear tire dealer to do the alignment. Then, when they approach Goodyear for/with you to get some compensation, Goodyear will trust their alignment changes.
I don't think this would happen if you had the alignment by one shop (say Freightliner) and then went to a Goodyear dealer to see if you could get some warranty compensation on the tires. In other words, Goodyear trusts the alignment specs of their dealers.

–Gordon

[mikeborny]

Originally Posted by gordonsick

Good news. I just got back from picking up my Berk at Fountain Tire, which is the Goodyear franchise in our area. They installed 2 new front tires G670RV 255-70R22.5 with a value of C$1496 for no cost. I paid for the alignment, balancing and installation, which came to C$322.76. That includes 5% sales tax and a tire recycling fee of C$18.

I was pretty pleased, of course.

The alignment was out, but I guess the Goodyear rep (who did come to the shop to look at the tires), concluded that the tires were substantially at fault. The total toe-out was 0.22°, where the acceptable range is 0.03° to 0.15°.

The rear axle is also out with a Thrust Angle of 0.4°, where the specified range is -0.04° to 0.04°. As someone noted in an earlier post, these rear axle settings are welded on, so they can't be changed. I guess the MH will always drive with a slight skew. I'm not as worried about that as I am with the toe out problem.

My MH has 35,000 km (21,748 mi) on it.

–Gordon

Gordon, i just noticed this on mine and called the goodyear dealer and does not know of any situation where they replace the tires for free. Any advice from your experience?

Thanks, Mike

[mikeborny]

Is this what the rivering looks like?

[dan-nickie]

Originally Posted by mikeborny

Is this what the rivering looks like?
Attachment 176340

That's what it looks like. I had it on one tire last year.

[gordonsick]

Originally Posted by mikeborny

Gordon, i just noticed this on mine and called the goodyear dealer and does not know of any situation where they replace the tires for free. Any advice from your experience?

Thanks, Mike

Your picture shows a worn shoulder but I don’t see scallops like I had.
Check with another dealer if you can find one. Our Goodyear dealers are independent franchises. You need one that handles truck and motor home tires.
Having said that, if there are no scallops you won’t get vibrations. And you’ll replace the tires long before they wear out. I can’t see any safety issue if you have no cracks.
Gordon