A full fluid change on the transmission takes about 10 quarts. The transfer case takes about 1.25 quarts. The torque converter is part of the transmission and not the transfer case. If you drop the pan you will only change a small part of the transmission fluid. To change it all requires pumping it out of the transmission. It runs about $80.00 at a transmission shop and about $130.00 at a dealership in most areas around the country.
Dave