Michelin 365 XZL Very Bad Tire Shake

[trider]

I have a set of new Michelin 365/85R20's mounted on 20" MRAP steel wheels I bought from Govt. Liquidation. They still had the Michelin stickers on the tires. I finally got my deuce bobbed and mounted them a few weeks ago. On the first test drive it shook like a dog starting at 30 MPH all the way up from there. I spoke to a few tires shops about it and they said to spin test it to see if the tires are round. So I placed a 2X4 under the front edge of the tire with it jacked up and spun the tire watching the gap between the tire and board. This revealed that one of my front tires has a high spot or two and the other has a low spot. Then I tested the back they also showed not to be round but didn't appear to be as out of round as the fronts. Tonight I decided to switch and move the backs to the front to see what that did. Well it might be a little better but still shakes so bad at 30-35MPH then at 50-55 MPH it feels unsafe. I drove it for a few weeks with the stock tires and wheels after bobbing it and it drove like a dream. Here is my problem I have called all the major truck tire shops in Oklahoma about the problem. They say the only fix is to possible tune or shave the tires and have them balanced on the truck but I can find no one in Oklahoma who can shave a tire that big. I called several tires shops in Texas and Arkansas that said they shave tires and everyone says they cant shave a tire that big except one tire shop in San Antonio TX who said he might could shave them and balance them but it would be at least $200 per tire not to mention I am about 12 hours from San Antonio. I have a buddy who owns a tire shop here in town and he said if the tire is out of round he doesn't think balancing beads will do much good. He called the largest re-tread shop in Oklahoma about shaving them and they said they wont do it either. Does anyone have any suggestions? I also made the mistake of selling my 12 spare tires and wheels that came off the truck and M105 trailer last night to a guy from Texas, so here I sit with a truck that is no fun to drive and feels unsafe. I am afraid my only option is to buy another set of tires and wheels as it seems like 9 out of 10 people don't have a problem with this when switching to bigger tires.

 

[m715mike]

This is interesting, and I'm curious what knowledge and advice others have to offer. Tires being out of round is not a problem I would have contemplated. I wonder how many others have experienced this issue with tires from GL?

I have Goodyear 395's on my truck. When I first got the truck last year, there was a terrible shake at 50-55 mph. My problem was loose lug nuts. Tightening the lug nuts eliminated 90% or better of my shake issue.

 

[162tcat]

Are you sure it's not your wheel adapters?

 

[trider]

Are you sure it's not your wheel adapters?

I can not be 100% sure about that. The only thing I can say 100% is it didn't do it with the stock tires and wheels. I bought the adapter plates from Peashooter. How can I tell if its the adapter plates? I used grade 8 hex head bolts to attach the plates to the wheels.

 

[DrillerSurplus]

I read an article where a guy moved the tires around to see if the out of round tolerances of wheels, tires & mounting could cancel each other out. Might be worth a try

View attachment TIRE RUNOUT TOLERANCES Bridgestone Commercial Truck Tires.pdf

 

[162tcat]

Peashooter has sold tons of those adapters so I doubt thats it but any good tire shop should be able to check them out and see exactly where the issue is.

 

[gringeltaube]

So how much (radial)run-out are we talking about, measured at the tire tread? 1/8"; 1/4"; more than that... ???
How true was the wheel spinning, radially - laterally? 1/8 of an inch? ... less?
How was the run-out measured/ controlled? Did you drive the truck for a while, then return home and immediately jack it up...?

Of course there could be other issues as well, like "loaded" run-out vibrations, etc. But first I would start by controlling the wheels, using a simple tool like a universal surface gage: I would say maximum 2 mm, radial- and lateral run-out. If more, then I would look for ways to correct it.
Second, check the tire run-out, if possible immediately after a ride, while still warm: even radial tires tend to deform a bit after sitting for a few hours, especially the front tires, having to carry much more weight.
Third and most importantly: try to eliminate tire wheel/ imbalance...! I'm sure that's where most of the shaking originates.
There are many threads here about different balancing methods. Just search for tire balancing, or start here if nothing useful comes up...

It is very unlikely that a brand-new XZL needed to be "shaved". Not even a used one. At least I have never heard of anyone having to this! But 99% of all shaking/ vibration issues we hear about had to do with unbalance... So better focus on that (...if it wasn't loose lug nuts, of course!)


G.

 

[rustystud]

I agree with gringeltaube (Gerhard) . I also would check the rims themselves to make sure they have not been bent or damaged in anyway. I'm sure of one thing, peashooter makes an excellent product so we can eliminate them from the equation .

 

[rustystud]

I read an article where a guy moved the tires around to see if the out of round tolerances of wheels, tires & mounting could cancel each other out. Might be worth a try

View attachment 492427

Interesting article .

 

[Cleptomaniac]

I have shaved some tires the redneck way. But not on a deuce.
Chain it to something then while parked over concrete jack it up, put it in gear, and let it down slowly. It will "shave" the tire/s. Not saying it's a good idea or even suggesting you should do it.

 

[Jeepsinker]

You just need to drive it. The uneven spots will work themselves out, but only if you drive it. Adding weight will help.

 

[peashooter]

If you want to check and adjust the balance, I can send you my bearing plates that will bolt onto a spare hub (if you still have your other rear axle to take one from). Here is the balancer I made which ended up being similar to G's setup. I'd avoid putting any beads on the tire if you have runflats in there because they will probably stick to the runflats lube and make your balance worse.
Here is the balancer plates you can borrow if you want: http://www.steelsoldiers.com/showthread.php?74670-Balancing-Tires&p=1263962&viewfull=1#post1263962

 

[trider]

Well I can say I have eliminated the possibility of loose lug nuts. I just checked everyone of them with my 3/4" drive breaker bar and cheater pipe. I did get about 1/4 turn on some of them and just got back from a test drive and maybe I am just wanting this problem fixed so bad its all in my head but I think that may have helped some of the shake. It is still very bad at 30-35 MPH but almost gone until around 50 MPH and it starts to come back. I have inspected all my rims and do not see any visible damage. I have tried the backs on the front as well and still have a shake, I am thinking the odds of have more than one bent rim is very slim so I am running out damaged rims. I wish I knew for sure if there was run flats in them but I bet there is so you are right peashooter balancing beads are probably out. I have a tire shop in the next town who only balances tires on the vehicle, they told be there computer balancer broker several years ago and they never replaced it because many people were requesting them to balance them on the vehicle. I called them last week and its a small mom and pop shop. I spoke with the guys wife about it and she said I would need to talk to her husband about if he could do it due to the size and weight. She did say the rim would have to have enough of a lip on it to clamp the weights on for it to work. I have not had time to call back and speak to her husband about it but if he thinks he can do it I may let him have a shot at it. Unfortunately I got the call yesterday I am getting sent out of town to work tomorrow until probably Friday. My day job is an storm adjuster for an insurance company and this time of year I am lucky to get to come home on the weekends so if I can find a hop who might be able to balance them it would be great. When you come home on Friday and leave again on Sunday it doesn't leave a lot of time to tinker with my truck as it seems every weekend the grass needs mowed and things need done around the house. Peashooter if I strike out of finding a shop I may be renting your bearing plates.

 

[peashooter]

Nuts... Have you checked your toe in at all and played with tire pressure? I've had people tell me of having wheel hop with both too high of psi or too much toe in... No idea if that will work in your case since it does sound like balance but these radial tires do handle different from the bias type. Oh and the bearing plates are free loaners, no renting required.

 

[trider]

Yes I have played with the tire pressure for a couple of weeks. With the M105 trailer bed on it, it seems very light and the rear end. On the rears I started at 50 PSI and dropped it in 5 PSI increments and am now at 25 PSI and as crazy as it sounds thinking I may try 20 PSI as they look and feel over inflated on the rear. On the fronts I started at 55 PSI dropped it in 5 PSI increments and was at 45 PSI but when I moved the rear tires to the front last night I went with 40 PSI in the fronts. It is a wench truck so a little extra weight up front. I am thinking the fronts are rear close to were they need to be somewhere between 40-45 PSI best I can tell. I have not checked the toe in. When we were moving tires last night my dad mentioned it looked to him like we needed to make a front end alignment adjustment as it appears the drivers side tire is turned in more than the passenger side. When the passenger side tire is straight it looks like the drivers side is turned in a bit.

 

[rustystud]

OK, I know this will sound weird but check your U-joints. A U-joint going out can cause the same vibration or shack of the whole vehicle. Since you have gone to bigger tires you are putting more stress on the driveline then the smaller stock tires would. At least until you get up in speed. Maybe you caused a marginal U-joint to finally "give up the ghost" .

 

[welldigger]

I don't think this will solve your problem but just for reference I run 35 psi in front and 30 psi in the rear of my 6x6 with 395s.

 

[gringeltaube]

OK, I know this will sound weird but check your U-joints. A U-joint going out can cause the same vibration or shack of the whole vehicle. Since you have gone to bigger tires you are putting more stress on the driveline then the smaller stock tires would. At least until you get up in speed. Maybe you caused a marginal U-joint to finally "give up the ghost" .

Not his case, I think. Read post #1 again: .... On the first test drive it shook like a dog.... Then in post #4 he says: 100% sure....it didn't do it with the stock tires and wheels...


G.

 

[Scrounger]

This sounds like a tire run out problem. The tires may not be seated true on the wheels. If you take a measurement from the wheel to a mold line on the side wall of the tire at say 12, 6 then 9 and 3 o’clock are the amounts the same? Sometimes if the tires are mounted with not enough lube they with seat unevenly. If that happens there be an uneven ride, I have a tractor that has two tires that need to have the beads broken and reseated that does just what you describe.

 

[searls84]

Did all the tires have air and valve cores in them when you bought them or were they flat? I bought a bunch of 395's on FMTV wheels from GL last year than had no valve cores in them. About half of them had water inside and had to be taken off the wheel and dried. May not be your problem but worth checking at least.