I have a 1999 Pace arrow motor home that sits on a F53 ford chassie the vehicle wieghs in at about 14,000# I have owned it for about 1 1/2 years, when I bought it there was a vibration when you drove it, I had the tires balanced at Discount tire $ 125.00 and the vibration was still there, the next step was to go to a truck tire center as the tires are 245-70r-19.5 and I felt that maybe Discount Tire could not balance this big of a wheel, The Truck tire facility said that the wheel were out of balance and they rebalanced them $90.00 but the vibration was still there, took the coach to Chucks speed center where I had the banks header kit installed and asked them about the vibration, they hoisted the coach up on a lift and suspended the tires off the ground while loading the suspension and found that the tires were out of round $140.00 went to the goodyear dealer who informed me that the tires while were not worn beyond warentee were to old, and he also check them with a dial indicator on his balance machine and the tires were out of round, so we purchased 6 new tires $1,600.00 and while the vibration improved it was still there, took it back to the goodyear dealer and he checked the new tires with the dial indicator and one of them was out of round so he replaced that tire. (no cost) however the vibration was still there, next I called Ford and they recomended Road force variance balancing so we had Sanderson Ford do this and again there was improvement but there is still a vibration in the steering wheel, next we tore apart the front end and checked all the bearings and seals found nothing wrong and reassembled, We also check drive line angles and all the U joints, am lost on what to look for next, any ideas?

 

What speeds do you feel it? Did any of the tire work you've had done change it i.e. speed it happens or intensity? There was a TSB for tie-rod ends and drag-link,but I can't remember if it was the Ford chassis or the John Deere though.

 

you can really feel it at 68 you cannot feel it at all at 40 yes with every modification it seams to have improved

 

My suggestion would be to try having the tires balanced "on the vehicle".Chances are pretty good that the tire/wheel assembly's are balanced,but you could have a rotor or drum that's out(you probably have disc brakes all the way around though).A 40-50 lb. rotor spinning 65-70 mph that's an ounce or 2 off is like a 13'' tire/wheel out of balance.A little vibration on some vehicles isn't that annoying,but in your case your sitting on top of the tires so you'll feel everything.

 

I have not been able to find anyone in phoenix that can balance them on the vehicle. have inspected the rotors to see if I could identify a weigh that might be missing but found no evidence of this,

 

Fixed the problem, found that the centering devise on the hub is 0.020 smaller than the hole in the wheel, to fix this I loosened the lug nuts, took two 0.010 feeler gauges and placed them at 4:30 and 7:30, rotaged the wheel so that the feeler gauges were now located at 10:30 and 1:30, tighened the lug nuts and took the feeler gauges out. you would not thing that 0.020 would make that big of a difference but it did!