A system and method reduce starting torque for initial rotational displacement and assure smoothness of motion for continuing displacement of a rotary joint. A rotary joint (either cylindrical or spherical) has a first annular joint member and a second annular joint member separated by a fluid-filled annulus. The second annular joint member is adapted for rotary motion with respect to the first annular joint member. A module fluidly communicating with the fluid-filled annulus creates vibratory micro motions in the fluid of the fluid-filled annulus which is between a pair of seals extending between the first annular joint member and the second annular joint member. The vibratory micro motions induce micro motions in the seals of the rotary joint. The micro motions in the seals reduce the initial torque for the initial displacement and assure smoothness of continuing displacement of either or both of the joint members.