I did try the brand new unused spare on the near side rear but it didnt make any difference. Reading some of the other threads the noise could be loads of things but seems to point to tyres, rear diff or transfer box.
I currently running well worn vederstein wintrac4 extreme tyres ( second set ive had on) and im wondering if its worth replacing the tyres ( but do i spend £500 on tyres and then find theyve made no difference and i still have the problem.)
I really like my FL2 but if i have to spend more time / money on it than neccesary it will be getting off loaded as i dont need the hassle / cost.

Ive had the car over the pit and jacked both rear wheels up.
Spinning the right hand wheel theres no real noise from the wheel bearing or the diff.
Spinning the left hand wheel there is a noise coming from the diff and not the wheel bearing.
Out of interest i took the oil out of the diff and found 700 ml of brown dirty looking oil. Ive replaced it with new 80/90 gear oil and ran the car. The oil did seem to quieten it down slightly but i know that isnt a proper fix.
I phoned a dealer today and they were a bit coy about it but didnt acknowledge this issue isnt new and will cost me £450 to fix!