'97 Explorer, Vibration/bearing noise

[ChrisH001]

My '97 explorer has devloped a very noticeable vibration which sounds like a knackered bearing. The noise appears to be coming from the transfer box (but difficult to tell with noises from inside a moving car!). Put it on the ramps and tried to find evidence of loose UJs etc. All I can find is that if I grip the rear output shaft (near where it exits the xfer box) and push it I can feel movement of about 1/16" which I don't think should be there! No leak of fluid though. This might be the cause of the vibration if that bearing has collapsed. Can someone confirm there should be absolutely no play here?

 

[liqhx2]

i would check the fluid level in the xfercase