904 auto. Transmission not shifting into gear

Hey my 73 Chargers 904 Automatic Transmission hasbeen leaking fluid for years now because I havent driven it and the other day Iwent to back in out of the garage but it wouldnt go into any gear. I checkedthe fluid and it was almost completey out so I put almost 5 quarts in and ranit and tried it again and the shifter shifts into gears, but the car wont move.The parking brake is off, so I dont know why it wont go in any gear so I canmove it? Any thoughts?
PSits been sitting in my garage for 8 years just now getting to work on it.
Author: sm73charger