It seems this rabbit hole will only go deeper. After having the center bearing support replaced, a vibration arose when taking off from a stop. After another inspection, the transmission mount was severed and the tailshaft housing was leaking and the bushing was very loose. Had those replaced tooday, and the vibration is still there, although lessened now. So that rules out center support assembly, transmission mount, and tailshaft play.

The U-joints seemed to be in good condition on the drive shaft, with no play, but they were never removed and checked. The differential oil is full. The wheels spun freely and silently while it was on the lift. Most of the vibration that was there at speed is gone, and my shifts are smoother too.

Any ideas?

Thanks,

Justin