I have a 2001 F150 4x4, V-6, auto, regular cab, short bed pickup. I've got about 43000 miles on it now.

Not long ago I began to notice an intermittent vibration in the driveline. By a process of elimination I've concluded the source has to be after the tranny.

I did a search of this site for similar problems and found some posts, specifically one by Edgex describing the same problem.

It seems to me the likely candidates are u-joints, drive shaft or discs/rotors. I don't see how anything else could be intermittent. I also can't imagine how the drive shaft could suddenly become intermittently unbalanced unless there's some kind of internal structure that is working loose.

I'd be grateful if Edgex or someone else, who's had and resolved this vibration issue, would tell me how they resolved it.