What a confusing debate!!
dazc2, on what are you basing the statement:
'Disco's, 90's and 110's all share the same transmition and are NOT.......i repeat NOT permenant 4x4'?
I am sure my Defender 90 was permanent 4x4 and it was always spinning all four wheels when doing serious off-road work. There was certainly no option to select 2 wheel drive, only a high/low shifter...