Has anyone figured out the cause for the vibration. I have a very similar situation. Drive an 02 f350 crew cab long bed. 102,000 miles on it. I can't say that I can make it happen, but I noticed laying on the pedal does seem to get rid of it. It seems to happen randomly, but I notice I'm doing about 40 mph. Sometimes less though. Garages don't seem to know either, because I can't always make it happen. The whole truck seems to vibrate. if I don't hit a bump or apply gas, it stays. Put it in nuetral and it's still there. Tried turning off overdrive, still there. Checked front wheel bearings and ball joints and took apart locking hubs and cleaned and packed with grease. Still there. Any help would be appreciated.