A torque shaft assembly includes a hollow tube with a central axis disposed between and fixedly connected to first and second crankshafts at first and second distal ends, respectively, of the tube for movement of an array of connecting members such as push rods. A hollow interior of tube between the first and second crankshafts is filled with a sufficient quantity of flowable inertia material or damping media to absorb vibratory energy by friction during operation of the engine. The hollow interior is preferably filled with a quantity of damping media to a level by volume of about 98% and a preferred flowable inertia material is round steel shot. A plurality of spaced-apart clevises are fixedly attached to a tube wall on an outer surface of the tube wall surrounding the hollow interior. Each clevis includes connection means disposed away from the wall outer surface for connection with an actuator for movement of the array of adjustable devices such as variable stator vanes.