What causes tag axle tires to scallop?

eagle19952 · October 12, 2011, 04:55:29 PM

Maybe...I can shed a tiny bit of light....
Luvrbus' theory (the down force) seems dead on to me, and here is why.
I bought a brand new two axle 16 foot trailer and hauled it 6000 miles (home) empty, no noticeable tire wear.....then I hauled it the exact same 6000 miles back...overloaded/full.
Because it was not level the tires on the front axle "scalloped".<BADLY>

$:-\$

the weight was primarily on the rear axle.
Being as thrifty as i am and cuz it was a trailer i rotated my tires every 1500-2000 miles to get my $$ out of them.
The next set of tires, no problem, and all i did was drop the hitch ball 2 inches.
Then again i could be full of mud.

belfert · October 12, 2011, 06:33:58 PM

Quote from: Len Silva on October 12, 2011, 12:50:04 PM
http://www.amazon.com/Gabriel-85314-FleetLine-Heavy-Absorber/dp/B004K7XQ2S

Notice that Amazon says it takes 1 to 2 months to get. Most of the results I found on Google were search engines that pointed back to Amazon or a few other sites. Some sites had no price listed. Ryder Fleet Products says up to 4 weeks to get. It really doesn't matter to me if it takes a month to get these as they aren't going to get installed until next year.

belfert · October 12, 2011, 06:51:38 PM

I really have no idea what the correct weight distribution between the tag axle and drive axle should be. Is there a hard and fast rule?

ruthi · October 12, 2011, 07:51:20 PM

Hmmm, this got me to thinking. When we are going down the highway as a certain speed, I think around 60, we get a vibration that seems to be coming from the tag axle area. If we speed up or slow down, the vibration goes away. Would that be from wore out shocks?

RJ · October 12, 2011, 09:27:24 PM

Ruthi -

Could be a tire, worn shocks, bad bearings in tag, or possibly a u-joint in the driveshaft starting to go.

FWIW & HTH. . .

ruthi · October 18, 2011, 08:30:33 AM

Thanks RJ

belfert · November 07, 2011, 03:45:05 PM

I took the bus over to Precision Frame in Elk River, MN today to get their opinion on my strange tire wear on my front tires and my tag tires. Dick the owner helped me out and said that there are no issues with the shocks or the suspension. He said the issue is with the tires themselves. One front tire has issues and one tag tire has issues. The tires are out of round and possibly not balanced properly. He said the front tire could be trued up, but that the tag tire is beyond hope. The tires may not have mounted properly to cause the out of round issue.

It looks like the best bet will be to get two new steer tires and rotate the steers to the tag axle.

Busted Knuckle · November 07, 2011, 04:23:37 PM

Brian,
Funny you should mention that.

A couple yrs ago I had a loaner coach from SETRA that rode so bad I parked it and told them to bring me another.
(this was after hauling a load of farmers to a CO-OP sponsored event and they told me they had tractors that rode better than the bus did.)

Several even told me they could make it ride better. When I asked how they told me to "start driving it in fields!"

SO Setra had me take it to a tire dealer that could balance the tires on it.
Which I did I took it to Best One Tire in Paducah and Setra paid them to take all the wheels off and balance them.
After that it rode somewhat better, but still rough.
Setra didn't think Best One did a good job balancing them and had me take it to another place where they tried to balance them and told me that some of them were so out of round balancing wasn't the problem or cure.
Setra told them and me we were crazy all it needed was balanced.

Well I parked it and only used it after the last of the 2 80's model MCI 96A3's we had then had left the yard.
When Setra finished our bus we took it back to them and I had the main guy over customer service got for a ride with me in it.
He immediately agreed it was terrible and told the service manager "I don't care what it is have it fixed TODAY, our reputation as well as our customers are being damaged by it!"

Well they tried telling me their local tire shop balanced them. But several weeks later when I was back over there I looked @ it and it had 8 new Firestones and I did not see one weight anywhere on the outside of a rim!

I now have all my tires done @ Best One in Jackson, TN and they inflate them laying on the ground lying flat and if it doesn't balance after the second time they call another tire up from the warehouse and send that one back. I watched 'm send back 3 out of 8 one day! But when I hit the rode that bus rode better than ever! (they have there own warehouse next door)
It cost me $150 or more per tire than it used to when I was buying my Kumho's directly from the tire warehouse in KY and having my local guy install them, but hauling people the ride is worth it.

BK

belfert · November 07, 2011, 05:03:09 PM

At least the front tires have weights on them so they were balanced when I had the tires put on. Balancing may not be the issue at all since the Precision Frame didn't actually pull the tires to check the balance.

At some point I will take the bus to a tire shop and see if they have the same opinion on the tires.

RichardEntrekin · November 07, 2011, 06:41:04 PM

This is a lot easier than arguing with tire shops.

First put a dial indicator on the tire. Micheline says anything over .050 is too much.

Second thing, kind of along the lines of what BK said, is to deflate the tire and rotate it 180 degrees. It isn't the rotation that does anything, its breaking the tire loose from the rim that is the key. Inflating it stretches the tire bead just a little, many times it will self center if you deflate it, break it lose from the rim, and reinflate.

Only after that, should you call foul on an out of round tire.

This is straight from the Michelin shop manual for truck tires, and from my sister who works customer service for Michelin truck tires.