rameller Report post Posted June 14, 2015 I have a 2007 Monaco Knight with a RR8R chassis. Two years ago with approximately 32,000 miles the driver side front tire outside rib was totally wore out and needed to be replaced. I went to a local commercial Goodyear Tire shop and asked for a front end alignment and 2 new tires. They informed me the front end was within spec and my problem was the rear axle alignment which was a negative 5/32. They informed me how the repair adjustment is done and I told them to proceed. Now, 2 years later with 20,000 miles on the new front tires the driver side outside rib is wore out. I went back to the same tire shop and they did another 4 wheel alignment and the rear axle is off a positive 3/32. The tech who did the first alignment is no longer their. My question: Why is the same driver side front tire outside rib wearing out? The axle was adjusted from a negative to a positive position and I would have thought the passenger side front tire would have been wore out. The motorhome is currently at a frame alignment shop and getting a laser 4 wheel alignment. The frame alignment shop confirmed the Goodyear alignment and that the front axle is within specification. They are adjusting the rear axle. I just purchased 6 new tires and want this problem to go away. Share this post Link to post Share on other sites
wolfe10 Report post Posted June 14, 2015 rameller, Welcome to the FMCA Forum. Exactly what were they adjusting on the rear axle? Share this post Link to post Share on other sites
rameller Report post Posted June 15, 2015 The frame shop will be moving the rear axle 3/32 (trailing arm adjustment) so its straight and square. I spoke with an individual with Monaco in Oregon and I said 3/32 is not that much off center. He replied when you take that angle out 27 feet it would be about 5 inches. I understand the geometry. He said they referred a number of units to Josam in Orlando for 4 wheel laser alignments and repairs. I have a frame alignment store approximately 20 miles from my home who does laser alignments and repairs. I telephoned Josam and communicated with a service writer. He wanted copies of the 2 Goodyear alignments which I e-mailed to him. He believes I have a front suspension problem and the driver side tire wear is not being caused by the rear axle being off 3/32. Again, I am really confused by the same tire wear result from a negative 5/32 to a positive 3/32 change to the rear axle. Share this post Link to post Share on other sites
hermanmullins Report post Posted June 15, 2015 rameller, Is your tire wearing out all the way around or cupping? Severe wearing on only one tire and on one side is an indication of Positive Top Camber. Again contact Monaco with your coach number and ask them for your alignment specifications. Although the shop close to you has 4 wheel laser alignment can they do motor homes? If yes and you trust them take the specs. to them and let them align you coach. FYI the specs for our 2002 Dynasty camber is: Left 0 degrees (+ or- 7/16 degrees) Right -1/4 degrees (+ or - 7/16 degrees). Herman Share this post Link to post Share on other sites
willtory Report post Posted June 15, 2015 I have a similar problem on a Freightliner chassis ('04 Itasca Meridian). Have had numerous alignments to include laser alignment of drive axle - he reported axle out 3/4 inch and cannot be adjusted. Freightliner says it can. Local Freightliner Service Center checked ($100) and said it was "within tolerance". Total spent for 4-point alignment was $425. So, I'm at a loss as to what is causing the right steer tire to wear abnormally. This is the 4th tire in that position. Share this post Link to post Share on other sites
rameller Report post Posted June 15, 2015 hermanmullins, The tire is wearing all the way around. The outside rib is gone and smooth. The driver side camber is a positive .2 degree. The passenger side is .0 degree. I will contact Monaco for the camber specifications. Thank you. Share this post Link to post Share on other sites
rameller Report post Posted June 15, 2015 WillTory, I do know a rear axle that is not straight will cause some rear tire wear. When my rear axle was out negative 5/32 inch it caused one of the 2 passenger side drive tires to have excessive wear. I had put 2 new tires on the front and moved the one good tire from front to rear. When they moved the rear axle they moved it to a positive 3/32 inch position. Now 20,000 miles later with 58,000 total miles I needed to replace the rear tires and the wear was pretty even. Share this post Link to post Share on other sites
willtory Report post Posted June 15, 2015 No argument with that....the truck laser alignment technician told me that the rear axle was out 3/4 inch, and the axle (Neway) on the Freightliner chassis could not be aligned. Freightliner told me that it could, indeed, be aligned and directed me to the local Freightliner Service Center. Here are the Service Invoice comments: "Set the coach up on the alignment rack to check the rear alignment. Found the ride height 3/8 low on the right. Adjusted as needed to level the coach. Measure the rear axle offset. The rear axle is only 1/8" on the target over the length of the coach. Good. No further action taken for the rear axle." The coach has new tires (all 6) so you know i will keep a close look at tire wear. Share this post Link to post Share on other sites
