Was sitting at a red light after it went green I started accelerating as normal and got up to about 10 mph and the rear end locked up. So naturally I put the car in park and back into gear and sure enough I get nothing. No power to the trans but the speedometer acts as if the car is moving. When the car is in park it doesn’t engage and the vehicle can be pushed both forward and backwards. I’m really hoping it’s not a bad trans but I checked fluid and it’s at a good level, and doesn’t smell burnt. Shift linkage also works. Any help is greatly appreciated

Transfer case in neutral maybe. Could also be a failed rear differential. Broken axle.