johnnyroper

as above need some advice on a 2.5 x3 2005 model year

when decellerating or coasting i am getting a whine type noise from 40mph down to 30mph does not happen at any other speeds,if i am decellerating in gear the noise stops if i touch the accelerator pedal.

i have read that the transfer box's can cause noise but i am more inclined to think rear diff.all fluids have been changed and it made no difference,there was no sign of metal in the old oils.

are there any common problems/things to check as i do not want to change transfer box only to find the diff is at fault.

thanks