PBR...You're making me worry now. I recently bought my VX used and have noticed a whine just as you are describing with yours (foot on the go pedal=whine, no go pedal=no whine). I think I'm going to do like jbregar and see if changing the oil will help. I'm hoping that the additive is just worn out and the oil back there needs to be replaced. I'm thinking that the person before me didn't go by the recommended maintenance schedule. If that doesn't work though, isn't the rear gears covered by warranty?