Front Prop shaft

So I was changing the oil yesterday and lying there on my back waiting for it to finish draining I was looking around at bushes and bulkhead, just generally having a nosy. I gave the front prop a twist expecting it to turn a tiny bit but it revolved at least half a turn. The car was in neutral but I still wasn't expecting that much play.

Is it normal or is something in the transfer/ front diff badly warn?

half a turn would be excessive ,theres allways some as both diffs and gears have freeplay in transfer box and diff ,crown wheel and pinion ,drive member ,half shafts do as well in front axle ,remove plastic hub caps and check drive members

Sounds like diff could do with backlash adjusting. My disco doesn't quite have that much play but I get about a quarter of a turn from the front.

The other place that gives play is in the transferbox. If you take the PTO cover off you can inspect the splines for wear. But it's quite common for most of it to have some play which then amounts to a lot at one end