My car does not go in reverse. on 2000 Ford Explorer

It was something that happened all of a sudden. It still drives forward. There is a whining noise coming from my car but I'm not sure if that's a related issue. Some friends I have talked to have said since it was something that happened all of a sudden it's probably a small fix but I'm scared it's not. Any advice on whether it's a small fix or does it sound like I need the whole transmission fixed?

Asked by for the 2000 Ford Explorer
Sorry, you need to see the transmission man! From what you posted it sounds like a broken reverse band. Trans. got to come out to fix. Shop can say for sure.