front d-shaft vibes

89 xj auto, have some slight play at the front axle pinion nothing huge, and I have some pretty good vibes at 55mph, and they are gone when the shaft is removed.all u-joints are tight, will that little centering ball cause vibes like that?Feels good when in 4wd and below 50mph

It sounds like it might be out of balance, but you're going to have to take it to a drive line shop to find out.

could be the cardan joint at the top wants rebuilding.
Pull the front shaft and look at it closely.
Mine had both the u-joints gone, but the centering ball was alright.
Two new u-joints and it's been fine.

Replaced the front, rearward joint and the centering ball, SMOOTSAILING, who would have though that little devil would cause so much vibes!!! 15 miniutes re+re and 20 minutes on the shaft , smooth!!!, That little centering ball was 70$ canadian!!