The invention relates to a pusher device (8) that includes a rotary bearing (10) having an inner periphery (11) that is off-center relative to the outer periphery (12). In order to compensate for wear, the bearing (10) is rotationally urged in one direction (F) by a spring (10) and is thus pressed against the back (9) of a rack (3) that is then pushed back against the teeth of the steering sprocket (5). The rotary bearing (10) is rotatingly mounted in a housing (13) that is in turn mounted on a steering casing (2) so as to be capable of sliding in a direction (B) parallel to a plane (P) of the teeth (6) of the rack (3) and orthogonal to the axis (A) of said rack. Shock-absorbing spring means (20, 21) are arranged between the sliding housing (13) and the steering casing (2) for absorbing the straightness defects of the rack (3).