Slunnie replied:

On my old toyota the thing just let go, though I suspect there was water ingress from a river crossing. I find that the bearings loosen and play starts to develop in the hub, but I don't know if this relates to an impending failure or if it's just normal wear.

PETER replied:

my 1999 disco done 78000 on and off dirt. towing 17' caravan ball weight 220k although truck restricted to 150k - never a problem with bearings - regards peter

ralph replied:

Having owned a 94 model disco I have experiece with this: fistly if the wheel bearing where not checked and tightened every 10,000km this will cause bearing failure :secondly the early discos had poor build quality and quit often inferior parts where used:thirdly factory installed wheel bearings where sometimes put in wrong (you know this because you get noisy brakes and front tyres wear on inner edge to fast ) this being a negative camber problem and would wheel align to factory specs
Do not refer this to rover because they will tell you are mad (like they told me) but with alot of expense I findly found the problem.