1998 ford van vibrations at 65 - 80. All began after new tire mounting 2 yrs ago. Have had it checked several times with different services and even ford dealer. Replaced tires and new bearings in drive shaft with no remedy. Can it be rims were damaged even tire dealer did not admit same. Should I consider a road force balance?
It could be damaged rims. If you move the tire to the front andsee if it changes then it could give you a hint. But if you put the rim on a balance machine an dspin it you shold be able to tell if it's bent or not. Youi could also have had a weight fall off another tingto check is the pinion where the driveshaft bolts to the rear end as they can be out of round as well you can 'try a fwheel balance on the truck as it may be a bad drbrake drum if it's got drum brakes as well, they have weights as well and one of those may have fallen off