A head stack assembly for use in a disk drive is provided that includes an
actuator body, a rotary bearing, a sleeve, and a cam member. The actuator
body is pivotable about an axis of rotation. The actuator body has an
actuator bore that extends along the axis of rotation. The actuator bore
includes an actuator bore surface. The sleeve is disposed between the
rotary bearing and the actuator body and comprises a first surface that
engages the actuator bore surface. The cam member has a second surface
eccentric to said first surface. The second surface engages the actuator
bore surface.