It can take up to 9 quarts to fill a Allison. Start with 7 quarts then start your engine and check the fluid. Make sure its to the cold mark. Once at the cold mark take you truck on the road for a 1 or 2 miles the recheck and make sure its at the hot mark. DO NOT start your truck until you put all 7 quarts in or you could set code and make the trans go into limp mode. Also when you replace the spin on filter make sure you put the magnet back on it. Just so you know I am a foreman at a large GM.
10 Chevy Silverado 3500 CrewCab
6.6L Duramax with EFI Live Tuner with 5 levels
560hp 958 Max torque 3:73 gears
2015 Crusader 351REQ