A viscous clutch assembly (100) includes a rotational input structure (110), a rotor (104) attached to the rotational input structure (110), a selectively rotatable member (102) surrounding the rotor (104) and rotatably supported by the rotational input structure (110), an electromagnetic coil (108) positioned relative to a driven side of the rotor (104), a valve assembly (106) supported by the rotor (104), and a magnetic flux circuit for controlling the valve assembly (106) with magnetic flux generated by the electromagnetic coil (108). The valve assembly (106) includes a cover plate (140) for regulating flow of a shear fluid. The rotational input structure (110) comprises a material capable of conducting magnetic flux. The magnetic flux circuit is configured to include no more than four air gaps (G1-G4).