EXPANDABLE PISTON ASSEMBLY
An expandable piston assembly for a clutch pack includes an apply piston, a stator, a rotor, and at least one side cover fixed to the stator. The stator is fixed to the apply piston and includes a first arcuate segment and a first radial protrusion extending from the first arcuate segment and including a distal end. The rotor is axially aligned with and rotatable relative to the stator. The rotor includes a second arcuate segment extending proximate the first radial protrusion distal end and a second radial protrusion extending from the second arcuate segment and including a distal end proximate the first arcuate segment. In some example embodiments, the first and second arcuate segments, the first and second radial protrusions, and the at least one side cover collectively form a portion of a first chamber for receiving a pressurized hydraulic fluid to rotate the rotor relative to the stator.