F150 vibration at high speeds

[fgross2006]

My 98 F150 vibrates when I hit 50 MPH.

I have 4 new Cooper tires just balanced.

Over the summer I replaced upper control arms, bushings and ball joints, Lower control arm bushings and ball joints, front hub bearings, shocks, U joints, rear shocks, rear leaf springs.

My mechanic says he thinks the source of the vibration is the transfer case, which is under the back seat. Before I go for a bushing and seal kit to rebuild the transfer case Id like to get opinions on this.

The vibration does feel like its coming through the power train, definitely not a tire balance issue.

[83gt351w]

I'd suspect the driveshaft to be the culprit. Have you checked for any missing weights? Heck, a dent would throw it off.

[fgross2006]

I'd suspect the driveshaft to be the culprit. Have you checked for any missing weights? Heck, a dent would throw it off.

I did change one U joint 2 years back but I would try re doing it.

Can the driveshaft be balanced off the truck?

[83gt351w]

Yup. Balanced just like a tire.