trying to rule out.........

[mike.strout]

1999 SD F-250 7.3 turbo. just bought it a month ago. I am getting vibration on acceleration from about 35mph-45mph in 3rd gear and from 45-55mph in OD. Im hoping someone can help ease my mind and assure me that this is not a transmission problem. It shifts fine, and there is almost no vibration at all if i'm into the pedal good. if its not transmission, anyone have any ideas what this problem might be? the vibration is pretty considerable. i just don't want to make anything worse by driving it.

[powerstroketom]

have you looked at your uj's on our tail shaft?

[mike.strout]

sort of, how can i tell if they are bad? tail shaft. is that what comes out of the tranny? or is that down by the differential?