...I get a sort of 'whine' in low gears (almost like the sound of a sequential box) and it is very noticable with windows open and driving in an enclosed space...more noticable on the overrun....I think this is normal and has somthing to do with the shape of the teeth on the cogs....every 197 I've ridden in has the same characteristic...not sure if this is the same noise you are having