Tire wear

[rchaines]

The front tires on my 05 Diplomat PAQ are wearing odd. They have 15000mi, just over one yr old and right front tire is wearing: second treat from outside by cupping. They are 22.5 Goodyear front truck tires, not RV. Left tire shows no wear or do other treads on right. Installing dealer is trying to blame shocks. Would shocks do this? I am thinking of getting two axle alignment at a tractor/truck shop and rotate to other side and re balance. Does anyone have other ideas as to cause. Maybe you experienced same wear. Roger Haines

[Mike Canter]

Cupping is not caused by front end alignment on MH because you normally have no camber adjustment and caster does not wear tires. Toe in adjustemt will wear both front tires across the middle. It can be caused by worn suspension components, bad shocks. Or the tire out of balance. We do have a problem with Goodyear RV tires rivering which is wear on the second tread in which is a Goodyear problem but it should not be cupped. Take a close look at your shocks and see if there is any oil leaking down on the lower tube. Also try taking the tire and wheel how it is and put it on a balance macine and see how far off it is.

[gregk]

Roger - Did you ever get to the bottom of your tire wear issue. I am having the exact same wear issue on the right front of my 07 Endouver. 19,000mi I may go ahead and change front shocks just for the ride improvement but would like to know for sure that I have solved the issue.

[Diplomat Don]

Roger....I have the same coach and had similar issues. I developed a bulge in the sidewall of my left front tire at 30000 miles. I replaced both fronts with new tires, had them spun balanced and had the front end aligned. I replaced my shocks within the first year to the Koni FSD's. I've done several things to make my coach ride it's best. The shocks were a huge improvement in eliminating the short frequency bone jarring ride. Next I checked my ride height and found it off by an inch both front and rear. Correcting the ride height smoothed out the coach even more. I weighed the coach and adjusted tire pressure to GoodYear's tire chart + 5psi.

Last summer when I replaced the tires I had a wheel wheel alignment done (first alignment since coach was new). The toe-in / toe-out was set at zero. The alignment tech said this would cause the tires to toe-out under driving pressure/force. He set the front end with a slight toe-in and this was another noticeable change in how the coach tracked.

When I replaced the bad front tire, I moved the other good one to an unmouted spare.

I would do the following in order of what you want to spend:
-High speed balance front tire (don't swap front tires-will cause issues and possible tread separation) set tire pressure to weight chart. Moving any of the rear tires forward and the fron tires back will cause an issue in height between the duals.
-Replace front shocks
-Replace front tires.
-Align front end.
-Replace rear shocks for overall better ride (pricey) Easy to do yourself if you're capable and have 1/2" impact gun.