Listen to this noise in the rear axlr

It is not between diff and prop/driveshaft, and not between crown and pinion, but on the outgiing drive shafts. The oil and cover plate are off as we determined the above. I hear nothing when driving, in either direction.
Perhaps there is supposed to be this play, but I doubt it.
How do I fix it?
(Tried to download the 5 sec video, but am not allowed to😨. It showed how one hand turns tge prop/drive shaft back and forth, creating this noise that suggests a very noticeable play in the diff)

Which car, which type axle? Read the thread from last month initiated by Andy about his 140 rear axle. It could be broken bolts on the crown gear, or bad bearings in the half shaft.

Sorry: XK 140 with original 3.54 diff

The very noticeable play is where the splined end(s) of the half shaft sits against the splines of the diff. Perhaps there is supposed to be a bit of play there. Again, I cant hear to feel the play when usung the car

Each half shaft fits into one of the horizontal smaller gears in this photo.
If the car is going straight both gears turn the same speed, but on a turn one turns faster than the other and then the other two small gears begin to work.
I’d say take the rear cover off, turn the wheels and look at the play.
But on a Salisbury from the mid '50s we expect to see broken or loose bolts on the crown.