A limited slip differential assembly comprising: a differential casing defining first and second output shaft openings that are co-axially aligned along an axis of rotation of the differential casing ; a first and a second side gear rotatably mounted within the differential casing , the first and second side gears being co-axially aligned along the axis of rotation of the differential casing , the first side gear defining a first axle shaft opening configured to provide a first torque transmitting connection with a first output shaft received within the first output shaft opening, the second side gear defining a second axle shaft opening configured to provide a second torque transmitting connection with a second output shaft received within the second output shaft opening; a pair of pinion gears mounted between the first and second side gears , both of the pinion gears being rotatably mounted on a cross shaft that is fixed for rotation with the differential casing ; a clutch pack disposed within the differential casing and including a plurality of annular plates interleaved between a plurality of annular friction disks , the clutch pack arranged on a first side of the cross shaft ; an actuator assembly disposed outside the differential casing and comprising a piston received in a piston housing , the actuator assembly configured to actuate the clutch pack , the actuator assembly arranged on a second side of the cross shaft , opposite the first side, characterized by a lug formed on one of the piston and piston housing ; and a groove defined by a groove wall on the other of the piston and the piston housing , wherein the lug is received by the groove and engagement of the lug and the groove wall inhibits rotation of the piston around a central piston axis . a differential casing defining first and second output shaft openings that are co-axially aligned along an axis of rotation of the differential casing ; a first and a second side gear rotatably mounted within the differential casing , the first and second side gears being co-axially aligned along the axis of rotation of the differential casing , the first side gear defining a first axle shaft opening configured to provide a first torque transmitting connection with a first output shaft received within the first output shaft opening, the second side gear defining a second axle shaft opening configured to provide a second torque transmitting connection with a second output shaft received within the second output shaft opening; a pair of pinion gears mounted between the first and second side gears , both of the pinion gears being rotatably mounted on a cross shaft that is fixed for rotation with the differential casing ; a clutch pack disposed within the differential casing and including a plurality of annular plates interleaved between a plurality of annular friction disks , the clutch pack arranged on a first side of the cross shaft ; an actuator assembly disposed outside the differential casing and comprising a piston received in a piston housing , the actuator assembly configured to actuate the clutch pack , the actuator assembly arranged on a second side of the cross shaft , opposite the first side, characterized by a lug formed on one of the piston and piston housing ; and a groove defined by a groove wall on the other of the piston and the piston housing , wherein the lug is received by the groove and engagement of the lug and the groove wall inhibits rotation of the piston around a central piston axis . <EOS>