Vibration/Shake at certain speeds

[golfknut]

I put new tires (Bridgestone Duravis R250's) on our 31' 2005 Jayco Granite Ridge back in July.
I believe ever since then I have noticed a vibration/shake at speeds between 38 and 50 mph.

I took it back to the chassis shop who installed the tires and they rebalanced them (found to be about an ounce off on each one). This helped a little but the vibration is still there. The shop told me normally with a balancing issue the vibration doesn't stop at a certain mph but continues on up with the speed increase.

I had it aligned when the tires were installed. The shocks are originals. Hellwig helper springs factory installed. 16,000 miles on rig. Air pressure in all tires is correct.

The shop said the drive train is as straight as an arrow.

The shop is questioning the accuracy of his balancing machine but calibrated it before rebalancing the wheels.

Any ideas what could be causing this?

I know these are stiffer (steel side wall) tires.
Could it be a shock issue?

[Old_RV]

Looks like it's fixed but perhaps the next time you have it in the shop:
Have them take a look at the drag link or center link. A worn link can cause uncommanded tire movement. Doesn't hurt to check.

[wolfe10]

Clearly, if this started after mounting the new tires, the tires or mounting/balancing was an issue.

With tires that have been balanced twice and "symptoms" still occur, the answer is to check "tire run-out". Any reputable tire store has a run-out gauge. It takes only 2-3 minute per tire.

But, a perfectly balanced "egg" will, well still roll like an egg.

I don't like to see front tire run-out of over .35".

[golfknut]

U joints were checked and are fine.

Tires were replaced 9 months after the original ones were purchased.
That couldn't be considered the same batch could it?

The chassis repair shop said they have put those same tires on several class A's and a couple of class C' s with no problems.
They were at a loss as to why they would cause an issue on our rig.

I liked the tires. They were quite a beefy tire....very heavy and looked like they would hold up very well.

[j-d]

Odd. We have R250s on our 31' Jayco that's not as heavy as your GR. They are Smooth, Quiet, and are Wearing Evenly.

Since the problem's gone away with different tires, doesn't sound like wheel or brake issues. All I can offer is this: Tires are made in big batch runs. A given warehouse could get all its inventory in a given tire from one defective batch. Replacements would still be from that bad batch.

[woodgeezer]

I would have your drive line inspected to make sure there is not a problem with the U-joints. Often the speed related vibration is caused by drive line imbalance. Sometimes it can only be corrected by having the shaft dynamically balanced. Happened on my Ford. It was masked by the bad tires that I blamed for the problem, new tires just made it more distinct.

Inspection and repair are not too bad, but should be done by specialty shop. They have the proper equipment. Seems to me I had a U-joint replaced on my little van for about $60-75. Did not have the balancing done which was $75.

[golfknut]

I thought I would give an update on this month's old issue.

After having all of the tires rebalanced last fall twice, at two different shops the vibration was still present.

All of the tires were replaced (with the exact same model) this spring and the vibration was still there.

A new set of tires was installed this morning (different brand) and the vibration is gone. WooHoo!!!!!

I have no idea why....I can only surmise that the steel side walls were too stiff for our rig. Rig too light? I don't know.

[crawford]

WOW now that's a surprise being new and when they balance it you would have see it, to think how did it be seen a second time.

[golfknut]

How is a broken steel belt diagnosed?

[Francesca_Knowl]

Long shot, only based on my own recent experience:

I was on a trip, also with new tires, when I noticed exactly the same sort of vibration only in my case at about 50 mph.

Since it started after the new tire install, I also suspected the tires, but it turned out to be a u-joint- no relation to the tires at all...

[crawford]

Like said before if you didn't have it before with old tires you shouldn't have them with new ones ,sounds like a problem with tires, but maybe a rim got bent while changeing tires. Also much tork on wheels. Also rear rims have a hole to aline rim to located valves opposite from each other. I once had my tire change and he bent the rim and pin

[RCMAN46]

If you did not have the problem before the new tires then I would also bet you have a bad tire. If they are radials there most likely is a broken steel belt in one or more tires. This can happen when they are mounted and they use a strap to get the bead to set and over tighten the strap.

[donn0128]

Bad tire. Had the same problem on a Mitsubishi once. Dealer was great, but we fought the problem for about a month before we switched to a different brand of tire. No more problems.

[CREATO]

Could very well be or could be a bad tire.