The back differential box gave out on me. Audible constant grinding of gears and leakage from the box. Underneath of car feels like itas jumping around and sounds like a chain in dragging. No prior issues or warning signs/lights beforehand. Had hit a pothole, and this terrible grinding noise started. Took to my local NTB and they didnat know the problem, thought a drive shaft initially. Took to Nissan for a second opinion and was quoted $4700 for a new back differential. I cannot drive it, as I donat feel safe, and its apparent gears have either shifted out of place, or broke inside there. Decided not to spend the money to fix, considering the car is 9 years old and isnat worth even $4700.