So I popped into the workshop and they're about to do the clutch. When he pulled the rear tail shaft off there was a pool of oil sitting between the tail shaft and the transfer case... Oil level in the t/case is fine. Once he separates the gearbox and the t/case he will have a look but he has never seen this on the t/case side of tailshaft... Can clearly see where it's been sitting in the round cavity of tailshaft ...
Thought I'd ask, is there a seal that could have gone? Maybe behind that nut somewhere in the photo on the t/case ??