A transfer case includes a two-speed range unit, a friction clutch, a
power-operated actuation mechanism and a control system. The actuation
mechanism includes an electric motor, a geartrain driven by the motor for
controlling rotation of an actuator shaft, a range actuator assembly and
a mode actuator assembly. The range actuator assembly functions to move a
shift collar associated with the range unit in response to rotation of
the actuator shaft. The mode actuator assembly includes a mode cam and a
ballramp unit. The mode cam is rotatively driven by the actuator shaft
for controlling the clutch engagement force exerted on the friction
clutch by the ballramp unit.