Considerable play in the transmission is pretty normal, mostly in the three differentials, but a little bit at every splined joint and set of gears. And it all adds up, especially with the centre diff unlocked. 
But normally it has little impact on driving unless the driver is pretty unskilled. However, if it is noticeable, it is usually the result of the handbrake dragging. This can be simply because of poor adjustment, a sticking cable, or more commonly because the rear seal on the transfer case is leaking oil onto the brake. Easy to check, either by jacking up the back (remember to chock the front wheels) and get under and check the prop shaft turns completely freely, or simply go for a drive and then check that the handbrake drum is not hot (careful in case it is!).
John
				
			 
			
		 
			
				
			
			
				John
JDNSW
1986 110 County 3.9 diesel
1970 2a 109 2.25 petrol
			
			
		 
	
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