my car will start but won't move

What is your question?

My explorer ran fine up until 3 days ago. I was about to turn in my drive way when the car lost all power, kinds bogged down feeling and the belt starting squeeling. I immediately turned in , put it in park and turned of the ignition. Determined the altenator locked up. Replaced altenator. Cranks adn purrs like a kitten but won't move. I have tried everything. Drive, over drive, reverse. Doesn't feel like its going into gear. But then I put it in Drive and gave it all the gas I could adn it tried to move. Kinda like when the emergency brake is on but its not. I checked. I even put it on and released a couple of times to see if it was stuck. I've checked all fluids, vaccumm hoses and everything is fine. We tried putting it in nuetral and getting it rolling then putting into gear and it continued to roll. Any suggestions?