Not sure about your coach, but when I changed the fluid on mine I replaced it with Dextron III. But the transmission on mine is the Allison 3000 MH six speed. I am pretty sure yours would probably use the same fluid. But you can always call Allison and I am sure somebody could tell you for sure.
2002 Gulf Stream Scenic Cruiser
2018 Buick Envision Essence
Neway Freightliner chassis
Aventa II Blue Ox