I have a '99 E350 passenger van I have been trying to figure out a vibration problem. All the way up to 67 mph it is as smooth as a Lincoln, but from there up a vibration emerges from where I think is the front driver side area. I have done new rotors/calipers, because it needed them, balanced tires numerous times, have put the fronts in the rear and those have not fixed the vibration. The van has 100k on it and I love owning it especially with the big V10. The vibration is just enough to be annoying and when driving it is almost like it cycles for 4 seconds for the vibration then smooth for 6 seconds. Any ideas or things to look into would be great.

 

I have been reading quite a bit here on the site and have read about starting with checking the ball joints, rubber bushings and tie rod ends, for wear and loose things that need to be replaced. Is there an easy way to check for a bad rim?

 

I had the tires balanced and rotated a few nights ago and I have now drove it enough to realize the vibration for the most part has moved to the rear. Tonight I checked bushings and ball joints for wear and everything seems pretty tight. I took the spare off and replaced it with the tire/rim that I thought was the problem and there was a huge difference. It has a slight vibration now that will be hard to pinpoint but it now rides like I expect. Fairly smooth but a huge improvement over what it was. I almost think one more rim is slightly bent but I will be driving it 3 hours tomorrow night so I will know more if that could be another problem. When I had the tires balanced last week I wanted them to take the spare tire rim and swap it with the one I thought was bad. Their answer was the spare was worse than the one I wanted swapped. Kind of ****ty when you want something done but get treated like you know nothing. That's not the first time that has happened to me.

 

A tire could be out of round and cause this.
Jack up the suspect wheel and spin it.