[pineaufamily1]

Getting some body vibration at 55+ MPH. rear drive shaft u joints seem tight (I was unable to see movement when trying to twist the yokes) and are rust free. I then checked the rear half axles. I would expect in and out movement for suspension travel but I get vertical movement and visible movement where the shaft meets the diff. when I move the shaft
vertically. The portion in the image rocks up and down. The front axles don't do this. Is this normal or are the CV joins worn? Thanks!

 

[speedlever]

Have you checked the center support bearing?

What year and miles do you have?

I didn't see any specs in the FSM regarding up/down motion for the drive shafts. Unless I misunderstood your intent.