driveline vibration, Shaft or U-joints?

[explorer pilot]

1994 4D 4X4. I have a rear driveline vib. I've removed the shaft and drove my front wheel drive EXPLORER, vib is gone. Has anyone had the shaft go out of balance or the slip shaft go bad? I'm changing the U-joints, but they aren't in that bad of shape(although they have 110,000). I have the usually shakes, but this is the only under acceleration vib. It is worse the harder the acceleration.

 

[88vert]

I would change the u-joints and grease the slip yoke and then go from there.Is the little weight still on the driveshaft?

 

[Byrd91]

If it's worse under harder acceleration it could be a bit of axle wrap maybe. What condition are your leafs and shocks it.