FIRST, I am not clear about something. You say the wheels roll when the car is off the ground. But, do they roll under power in drive and reverse? Or are you just rolling them by hand? If I were you.... I would get the car safely up in the air. Start car with foot on brake. Pull it into drive, and see if the wheels still resist moving. Hit the brake again, to get the wheels completely stopped. Then do the same in reverse. That MAY tell you more about the condition. Then, I would pull the pan and drain the fluid. look and see if there is much debris or metal particles in pan. Pull the filter and check for obstruction. Let us know what you find.