wont shift to 2nd locks down trans/rear end what could be wrong?

AOD Transmission when time to shift to 2nd gear at roughly 30mph locks rear end believe transmission or torque converter possibly. lifted car off ground and tried when hitting 2nd gear second point locked up passenger rear pulling wheel and driver rear kept rolling. What could make it do this help. with it on the stands should i be able to turn the wheels with the car in park. the driveshaft does not turn but the wheels do the pulling wheel goes forwards and the driver wheel spins backwards at same time by locks with it on stands soon as it gets almost 30mph the driveshaft stops sudden and the pulling wheel locks in place like e brake and the driver rear keeps spinning until it stops on its on
Is this the sytmptom of broken band, gear or what in a transmission thanks. Always ran fine til one day locked up going in gear towed home.