Uneven Tire Wear - What's the Cause?

[five]

Of my six 295/80R22.5 GY 670s, with 25k on them, five are totally even in wear. However, the right front appears to be totally even in wear, except the outside band (about an inch) is showing much more wear than the rest of this tire or the other tires. The wear seems to be all the way around the tire. All tires are well under their gross weight rating and are properly inflated.

Any suggestions as to the cause and/or a fix would be appreciated.

[dickandlois]

Allegiance40x, Check the ride height on the the front right.

The Camber angle might be off, set to positive.

Tow out ? is a static alignment made to minimize tire scrub and rolling resistance, that develop when a vehicle is cornering.

Rich.

[tireman9]

My first thought is Alignment with Camber being the most likely culprit. Toe is more likely to cause uneven wear of both front tires but just getting the alignment checked and set to spec will cover both.

One thing to ask fo is a printout of both the Before & After measurements.

[five]

Thanks guys. I'll check it out and let you know what happens...or doesn't happen.

[five]

Okay, making progress. Went by, without the MH, and talked to the service manager of the big rig alignment place. Since I have independent front suspension, he said he could align the front end fine. However, since then I've been reading about aligning the "thrust line." That is supposed to bring "the rear wheels into coincidence with the vehicles geometric centerline." Then the front wheels are aligned to the identical geometric centerline/thrustline. This results in "total four wheel alignment insuring all wheels being parallel and the steering wheel and the steering geometry being centered as the vehicle moves in a straight line." Translation...it's like four wheel alignment we get on our cars.

Is this something normally done on one of these rigs?

Appreciate the help.

[wolfe10]

In a word, YES. 4 wheel alignment is common on all vehicles.

[dickandlois]

This is an item that is missed on a number of larger chassis and was often missed on older cars.

When the rear of the vehicle, viewed from behind tracks to the left or right of the front, we always called it dog trotting. They always look like there running at an angle when traveling is a straight line.

Rich.

[tireman9]

In a word, YES. 4 wheel alignment is common on all vehicles.

x2

[mpierce]

I ALWAYS get all axles aligned on our Class 8 Peterbilts. If the rear axle/axles are out of alignment, they will "push" the front end. Once the rear is straight, then the front can be aligned correctly. Find a good, heavy duty alignment facility, where the big rigs go! Don't mess around with RV or medium duty places. The big boys know what they are doing.

[five]

Talked to another big rig tire/alignment shop on Sat. He said my MH had no way to align the rear wheels...guess he doesn't understand MHs.

[wolfe10]

Suspect he means there is no EASY way to align the rear wheels/axle.

[five]

Suspect he means there is no EASY way to align the rear wheels/axle.

Okay, so is it something I should find a shop that is willing to do...is it worth the cost? Any idea what that cost would be?

[wolfe10]

Let us know where you are and perhaps someone will know a shop in your area.

And, we really have no idea if it is needed or not. Only putting it on the alignment machine will tell.

Cost can vary quite a lot. Again this is not a real common issue, but to fix it often requires breaking welds that locate the rear axle, alignment and then rewelding. For more information on what would be required, do a search on the model of your rear suspension (you chassis maker is a good source of this information).

[five]

Okay, thanks. I'm in NW AR...Fayetteville/Springdale/Rogers/Bentonville and Fort Smith, is to the south. It's an American Coach on a Spartan chassis, I'll call them in the AM.

[dickandlois]

Allegiance,

There should be reference points on the frame to measure from, to a point on the rear axle; when these measurements are equal the rear should be aligned. This information should be in the the Spartan chassis maintenance manual.

I travel with the Chassis Manual for our coach because not all service centers have the proper information.

You might give Spartan a call and see if you can get a copy of the rear alignment information along with the proper settings for the front.

Like Brett said, there is no easy way to set the rear alignment and it takes a shop that has the proper equipment to do the job.

Rich.

[five]

Here's what I did.

Called Spartan, got a very knowledgeable and helpful guy. He gave me the specs for both the front and rear axles. Then went to a big rig truck alignment shop. The tech checked the rear, it was WNL, then checked the front...off considerably. He aligned the front and gave me a print out of 'before' and 'after.'

Appreciate the help from all.

[pmarth]

I want to get my 2006 Damon Daybreak alignment checked. Can anyone recommend a good shop in San Antonio? Thanks