A viscous fluid shear device that includes a floating wiper. The wiper defines at least one fluid channel on a surface of the wiper that faces a circumferentially extending surface on a rotor. Each fluid channel has a first portion, which is formed with a first cross-sectional area, and a second portion that is formed with a second, smaller cross-sectional area. Each of the first and second cross-sectional areas is defined by first and second planes, respectively, that extend through the central axis. The second plane is spaced circumferentially apart from the first plane in the predetermined rotational direction.