Individual U-joints shouldn’t have any noticeable play when twisting on them hands on each side/ The overall linkage from the transmission output, through the driveshaft, then differential, and then axle shaft will normally have some play though. I did that measurement on my truck’s rear wheels recently, around 4 degrees of play at the wheel as I recall.
Common causes for these sorts of clunks
- idle rpm too high
- worn u-joint
- 2 part driveshaft needs its splines to be re-lubed
- suspension system , especially the springs & spring mounts