Don't know which 4 speed you have but...I just changed the oil in my AT545. In my case I have the deep pan and I drained 4 gallons, filled with 4 gallons. Did not change the pan filter but did the inline spin on.
Don, Mary and Spooky
'00 Bluebird Skoolie Conversion
Geo Tracker/Dodge Neon/Aprilia Scooter towed