Took our coach to the shop to have our tires inspected before heading out this summer. All looked good except right front which had some minor cupping on the inside shoulder. I had them switch the outside rear with the right front as a precaution. Without any symptoms of that alignment, or out of balance, what are the potential things I should be looking for as the cause of this where pattern.
Doesnt that change the tires rotation? I avoid that for the big tires.
The switch was passenger front to passenger rear outside. Same rotation.
Andy,
There can be several causes of cupping. The cause is the tire bouncing because of:
Out of balance tire
Worn suspention componants
Tire out of alignment.
Run over a smooth road at different speeds and see if you can detect even the slightest vibration in the steering wheel. Go up to at least 65 mph.
If you can't do it yourself have that wheel lifted so the suspension is not bearing any weight then check for worn or loose components.
If all is OK have the alignment checked at a place that does big truck alignments. A good machine will be a computer aligner that will not only check front end but rear as well as front to rear alignment.
Keith
Can the rear be adjusted if its out? I was told by the alignment place they could not but I have never looked to see if it was able to be done but they do not want to do it.
If the coach is not crab crawling there is nothing an alignment shop can do. If it is crab crawling something is worn out or broke.
My top 3 reasons Trailing arm bushings slop, Panhard bar bushings slop, or bulkhead joint failure.
Mike
Could the cupping possibly have been the tire rubbing on the bottom of the rearmost air bag?Remind us,have you installed new shocks recently?I would consider having the balance beads installed or getting the concentric system.
Arent the rims flipped from outside to front?
Mike - dismounted and remounted.
John - new Koni's in the last 3 years. Since they're 295's from previous owner that may be a factor. Gonna have a closer look at the airbag mount tomorrow.
I asked because we just saw one of Bob's (journey roam and explore)tires with a gouge that could have been mistaken for a
cupped tire.
Could be a loose or failing RF wheel bearing. If you take it in for an alignment it might be a good idea to have both front wheel bearings checked for clearance/failure before doing the alignment.
They track poorly with loose bearings. Wander etc. Zero plus a pinch .