Increasing vibration

[Teligence]

I have a powertrain vibration that has been slowing increasing over the last 10,000 miles. The rear end was rebuilt about 20,000 miles ago. There is no (radial) slop at the rear end input shaft, no play in either of the U-Joints, but a little bit of radial play (side to side and up and down) at the front slip yoke. Is this normal, or is it time to pull the extension and replace the extension seal/bushing/bearing?
2003 Ram 1500 Laramie - 5.7L - 545RFE tranny.

 

[Bloody_Knuckles]

Not normal.