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mojoracing · 03-09-2016, 05:50 AM

I have weighed my coach several times since new although have never had it weighed on all four corners. Once I explain my problem, I dont think having a weight for all four corners will really pertain to this issue. That being said, I recently notice a problem with both steer (front) tires. Both outer edges on both tires have worn excessively. The outer rib on both the outer and inner edge of the tire has worn down to wear there is actually a sort of step down. This is happening on both front tires. I run 80 psi in the front which matches usp with Michelin's inflation chart for weight. The Tires are Michelin XRV's 235/80/22.5. My common sence says this is an under inflation issue but again, according to weight it should be spot on. Should I try running higher pressure to correct or at least stop it from getting worse? Is there a name for this type of wear? The tires have 22000 miles on them and are 3 years old. They are perfect in every other way and the rears are wearing really well.

Ranger Smith · 03-09-2016, 05:53 AM

It appears to be low tire pressure.

jenandjon · 03-09-2016, 05:53 AM

put in a 100 psi and maybe an alignment.

twinboat · 03-09-2016, 06:01 AM

Wear on the inside or outside tread indicate alignment.

Balance will give you cupping.

Wear both inside and outside indicates under inflation, unless you have a Ford twin I beam suspension.

What psi does the MH manufacture recomend ?

spritz · 03-09-2016, 06:24 AM

Running over the white line is also not good for them.
JMO< Tim

barmcd · 03-09-2016, 06:36 AM

Even wear on both outside edges is a sign of under inflation. 80 lbs sounds pretty low for most Class A RVs.

Gary RVRoamer · 03-09-2016, 07:25 AM

If it is just a single ridge and looks like a step, that is NOT an inflation issue. Under inflation would wear both sides of the tire in a smooth fashion.

What you describe is called erosion wear, or sometimes "rivering" if the wear line is a bit wavy. It is a common phenomena on the free rolling tires (e.g. steer axle) of some vehicles and some types of usage. The tire industry does not consider it to be a problem, since the whole tire normally wears out (or ages out, in an RV) well before the ridge becomes a problem. These photos from Michelin show the problem:
https://www.michelinb2b.com/wps/b2bc...ects_Steer.pdf

Or if you want to really understand what is going on, see this tire analysis guide for all types of tire symptoms:

http://www.euroratas.lt/galery/_euro...ysis_guide.pdf

larry koenn · 03-09-2016, 09:00 AM

Gary is spot on. The problem is not your motor home but the tire. I fought it for several years on my Monaco because I was such a fan of Michelin tires. The Same thing occurs on many motor homes and big rig trucks with Goodyear tires. Both Michelin and Goodyear will not address the problem.

I could not get more than 25,000 miles out of a set of Michelins on the front of my coach and switched to BF Goodrich ST tires three years ago under advice from a long haul truck driving friend. I now have a little over 35,000 miles on the front tires and they still look like the day they were installed. The ride and stearing is also better than with the Michelins.

Michelin will never get a dollar out of me again.

Good luck
Larry

Mike and Cha · 03-09-2016, 10:55 AM

Mojoracing, we have similar MH's in size and weight and mine do the same thing. Mine doesn't sound quite as bad as yours, but enough for me to have had the alignment/balancing checked even though it drives great. I was told this is normal for Michelin tires. I run my front tires at 92 psi and it keeps the wear difference to a minimum.

Bigd9 · 03-09-2016, 12:01 PM

Does it look like this? Picture is from Motorhome Magazine, but looks exactly like my front Goodyear tires looked when I noticed the problem. They got a LOT worst fast. The Goodyear dealer I took them to said "oh we see that all the time, and its normal". I left there and bought Bridgestone tires.

mojoracing · 03-10-2016, 05:23 AM

mine does not look like that. It is a well defined step on both the inner and outer ribs. The center few ribs are fine and it also does not have the wave, it is an evenly worn step, roughly 1/3 to 1/2 the outer and inner rib. Looks like the second pic in michelins tire guide that Gary posted. The third example in that tire guide is hard to discern although the description they give sounds right other than the wave pattern. The RV drives perfectly, no reason to check alignment or balance. In a previous life I was an certified auto mechanic but never dealt with large chassis vehicles and have never seen tire wear like this. To me, the classic sign of underinflation is more evenly spread to the outside of the tire, this is different. I went up in pressure hoping like someone else said to stave off the effects and hopefully create a more even wear. I have checked my tires consistently and this only started to show itself in the last 2=3 thousand miles.

mojoracing · 03-10-2016, 05:38 AM

After looking at that Michelin tire wear chart, I take back what I said. The second example labeled step wear kind of got me because its labeled step wear and thats what I have but that corresponding picture seems to show smooth wear to the outside ribs and that is not what I have. Mine looks more like the third pic labeled errosion/river wear but with no waves that I remember. I have to stress that there is a well defined step that I can definitely see and feel with a finger. To me, if it continues this way, the outside edges will wear down much quicker to unsafe/worn out levels while the inside ribs will still have tens of thousands of miles on them. Funny, I just commented on another post a week ago about Goodyears doing the same thing and told the guy how happy I was with my Michelins. Will Michelin do anything about this? Is there a place that sells Michelin that is more responsive to this issue? I really love the way the tires ride and handle but to me this is a defect and should be handled by warranty. Michelin says it themselves in that wear guide, they themselves call it "an IRREGULAR TIRE WEAR CHART"! Their solution is literally to do nothing and keep running it. I will follow anyones advice here that has dealt with Michelin and give them the benefit of the doubt but if they do not help out and warranty the issue it will be the last set I ever buy. My previous motorhome had Michelins and they went 80,000 miles. I cant see this as normal in any way shape or form.