Run out on the wheels and tires at 50 thousandths does not seem excessive to me and I think that if that was the cause of the vibration, it would not go away but would increase at higher speeds(revolutions). When you pulled the rear prop shaft and the vibration went away, I believe you have narrowed the cause of the vibration to the prop shaft and rear end. I had a GM Cutlass that had a weight hanging off the front end of the pinion housing that was there to remove vibration(but that was a coil spring car) I am now of the opinion you have a pinion angle problem or a bad U joint. This would cause a vibration at certain speeds, but not at higher or lower speeds. Have you put an angle gauge on the pinion and the carrier bearing? Maybe the prop shaft is out of balance; but again, I think if it was, the vibration would get worse at higher speeds. I can't believe the springs would have anything to do with it because even if the springs were froze solid, the shackles would absorb a lot of the vibration of something that was out of balance in the driveline. I gotta be truthful with ya, I've drove a many of these trucks 1/2 ton to 3 ton and I have never felt anything in the seat of my pants the way you guys are talking. Joe
