O.k i've just bought a 91mr2 and i'm slowly working through the process of getting it tidied up.I'just got a full service on it,including changing the gearbox oil.I've got a new exhaust on it which is very quiet.Now when i accelerate and then just back off,i get a whining /grinding sound,does this mean my gearbox is stuffed or the diff.It's really quite loud,just wondering if anyone with an mr2 has had the same problem