how much play in rear half shafts

I have a noise in the rear when I have my 96 legacy wagon in 4 wheel drive.I have checked the drive shaft and it appears tight. the wheel bearing seem tight and good . My have shafts have about 5 degrees rotational play in them on the diferential side. any suggestions.
Himie

The play is due to backlash in the gears, I wouldn't be concerned about that - the same thing exists in your gearbox.