Community Forums

calhyatt · 07-15-2012, 10:49 AM

Just got back from a 3000 mi. trip with my 2003 3905 Kountry Star. My right front tire is starting to cup, on the inside of the tire on just 1/2 of the circumference. Is this balance, alignment, shocks ?. I can't seem to get a definitive answer from anyone I contact. I don't want to go on a goose chase, just get it fixed, first visit. Any help from you Forum experts would be great. My local Newmar dealer sends all this out to a vendor so they have been no help in diagnosis..

Tom-NC · 07-15-2012, 11:00 AM

Hi Cal,

Cupping can be caused by tire balance and wheel out of round. I was in AK and lost a tire weight that was on my right front tire and it caused cupping. It was so bad I had to have tire replaced as the cupping will not go away after you have tire balanced. I had the other front tire checked and it was out of balance but because of steel wheel being out of round.

Interestingly I learned that is why 18 wheelers use aluminum wheels on their front wheels as they never get out of round.

Hope this solves your problem get them balanced and preferrably while wheel is on vehicle.

DonDee · 07-15-2012, 12:59 PM

I would start with balance.

stuhly · 07-15-2012, 01:57 PM

If the tires are the same, move it to the rear and move a rear forward. The cup will stop on the back.

GaryKD · 07-15-2012, 06:00 PM

Hi calhyatt,
My coach is similar to yours. Do what has been previously posted. In addition, if you still have Bilstein shocks, get rid of them. Put Koni shocks on the front. If you have the $s put them on the rear also. A front end alignment would put icing on the cake.

calhyatt · 07-16-2012, 06:38 AM

Quote:

Originally Posted by Tom-NC

Hi Cal,

Cupping can be caused by tire balance and wheel out of round. I was in AK and lost a tire weight that was on my right front tire and it caused cupping. It was so bad I had to have tire replaced as the cupping will not go away after you have tire balanced. I had the other front tire checked and it was out of balance but because of steel wheel being out of round.

Interestingly I learned that is why 18 wheelers use aluminum wheels on their front wheels as they never get out of round.

Hope this solves your problem get them balanced and preferrably while wheel is on vehicle.

Thank you for your advise on my tire cupping problem. I will now go to a reputable truck tire store and do as suggested.

calhyatt · 07-16-2012, 06:39 AM

Quote:

Originally Posted by stuhly

If the tires are the same, move it to the rear and move a rear forward. The cup will stop on the back.

Hopefully the front tire is in good enough shape to move it to another position. Thanks for the advise.

clyon51 · 07-16-2012, 08:27 AM

Cupping can also be caused by under inflation and has always been the problem for me. Never on my RV though, I'm a stickler for tire pressure there

calhyatt · 07-17-2012, 08:05 AM

Quote:

Originally Posted by GaryKD

Hi calhyatt,
My coach is similar to yours. Do what has been previously posted. In addition, if you still have Bilstein shocks, get rid of them. Put Koni shocks on the front. If you have the $s put them on the rear also. A front end alignment would put icing on the cake.

Thanks for your advise Gary. Getting things looked at tomorrow.

calhyatt · 07-18-2012, 08:35 PM

Got the front end checked today. There was a toe out condition but not much. All back to factory now.. The main reason for the cupping was the shocks on that wheel. It is shot. Bushings bad, possible leaking. Moved some tires around and got alignment and shocks. Tires re-balanced. All is well. Thank all of your for your advise and help..