Thanks guys I have never changed the fluid in 5 years except when I replaced the flexi hose to the steering box it only makes the noise for about half mile then goes away but only started doing it a few weeks ago
Well thanks for all the info guys taking everything into account I think I will be sticking with the original transfer box and putting my complete disco 300 r380 box up for sale so if anyone in spain needs 1 call me
thanks again guys