So my car has had this whinning noise now for a lil and its gettting annoying . ive searched and read for a while and it seams to be either the rear diff is going bad or this is a normal sound from an sti . for a while i thought it may have been a wheel bearing but i think i ruled that out since the tires dont have any play when i lifted them and rocked them . another thing it seems to be is possibly a carrier bearing on the diff . the noise comes when im going 35+ and when my foot is on the gas or when the cruise control is trying to accelerate. as soon as i release the gas the noise goes away . i found a clip on youtube from an audi that has the exact same noise. he describes it as rear diff whine , and nothing else. later down on the comments he says it was a bad pinion . has anyone ever heard of a rear diff making this noise. or is this a normal sound the sti makes . im thinking there gotta be somehting wrong , ive just never messed with a rear diff or any of its internals .