18" Stock Wheels- Question

[tomdietrying]

O.K. I'm running 285/60/18 Nitto Terra Grapplers. I've had them 13 months, about 15,000 miles. A couple of weeks ago I started noticing a vibration when I got over 20 mph. The first thing I did was go to Dicount Tire and had them rebalence them. It got a little better but not much better. I then thought it might be internal. I took it to a place that used to be an Isuzu dealer. The same Isuzu techs are there, but they no longer sell Izusus. Anyway, they ran a diagontic. They couldn't find anything wrong. They didn't charge me because nothing came up, but they speculated it was the tires. I then went to another Discount Tire. They rotated the tires. It was still the same. I felt comfortable going 55-60 mph. Anything more than that it got too load. They then sent me to still another Discount Tire where they had a this special machine that would really balance them. It's called a Road Force Balancing. After they did that it did help. I felt comfortable going 75mph, after that I didn't feel safe. Usually 90 mph and it rides really smooth.

Here's my problem. The last guy that balanced my tires tells me....."You know those tires are too big for that rim." Now, I know if you punch in VehiCross in the Discount Tire computer it says anything over 245/55/18 cannot fit. Now does that mean that the wheel is too small for anything bigger than that or Izusu wants a smaller tire for a smoother ride?

I've been running 285/60/18 for over 5 years. Did my tires suddenly go bad and shoud Discount replace my tires.

What your take on this?

Peace.
Tom
012009

[Ldub]

I'm still thinkin' it's a crooked (seperated) belt in the tire...try to find another tire vendor locally (not a Nitto vendor) & have them look for a belt seperation.
Could also be a bent wheel, but if you haven't had any run in's with immovable objects,(curbs etc.) not as likely.

[rowhard]

tom, are you feeling in your seat or the steering wheel? Reason I ask. I have been noticing a bit of a shutter in the seat of the pants, 20 mph +. Wasn't sure IF it was wheel or drivetrain. Today, I had a 20k X-mission fluid change and you know what, I think it is better, but I won't swear to it,... yet

[tomdietrying]

Rowhard, I feel it in the steering wheel and it ne seat. Scott came over and he sat on the back floor (I took out the back seat). He thought he felt it in the rear.

Ldub, how do you check if there is a seperation. That's what the guy speculated at the first dealership I went to. I told Discount that and they said...."those tires will not seperate....the only way they will seperate is if you have a tear in the steal belt and then use something like Fix a Flat."

Peace.
Tom
012009

[Ldub]

Rowhard, I feel it in the steering wheel and it ne seat. Scott came over and he sat on the back floor (I took out the back seat). He thought he felt it in the rear.

Ldub, how do you check if there is a seperation. That's what the guy speculated at the first dealership I went to. I told Discount that and they said...."those tires will not seperate....the only way they will seperate is if you have a tear in the steal belt and then use something like Fix a Flat."

Peace.
Tom
012009

The statement ...."those tires will not seperate....the only way they will seperate is if you have a tear in the steal belt and then use something like Fix a Flat." , is just "blowin' smoke"...there's not a tire made that hasn't had a few failures...it's the nature of the beast.
If they put it on a balancing machine, (tire verticle) & give it a spin by hand, you'll see the tread wobble (L-R, or R-L)...My thinking on this is, if you take it to a dealer that sells a non-Nitto brand, they'll be more likely to point it out.
(cuz they want to sell you new ones)

Have them use tire chalk to mark the problem area, if found. Then take it back to Discount Tire.

Hope you find the source of your vibration.

[tomdietrying]

I think I found out what was causing the wobble/vibration. I took it to one of the last remaining authorized Izusu dealers in Texas. The mechanic turns out to be very knowledgeable and a former VX owner. He immediately suspected the U-Joint. I should get it back on Monday.

He seemed pretty convinved that would solve my problem. I'll let you know.

Peace.
Tom
012009