Abstract: A combination range and master clutch assembly includes a separator plate, at least one clutch, a fluid actuated main piston for engaging each clutch, and at least one fluid actuated accelerator piston. The separator plate and main piston define first and second main chambers in communication with each other. The main piston and each accelerator piston define an accelerator chamber. Sliding of each accelerator piston blocks communication between the main chambers. The assembly is controlled by providing fluid at an operating pressure which may be modulated between low and high pressures. Fluid is selectively delivered to an accelerator chamber at the operating pressure when it is below a threshold pressure level, and to both the accelerator chamber and its associated main chamber at the operating pressure when it is above the threshold pressure level.