A hydrodynamic bearing includes a housing defining a central axis, a pad slidable relative to the housing in a direction substantially parallel to the central axis, a cylinder defined in one of the housing and the pad, a lubricant port in fluid communication with the cylinder, and a piston at least partially positioned in the cylinder. The piston is movable within the cylinder between a retracted position and an extended position in response to a flow of lubricant through the lubricant port to vary an axial spacing between the pad and the housing.