Abstract: A steering assembly (10) for turning steerable wheels of a vehicle in response to rotation of a vehicle steering wheel (11) comprises a housing (30) and a member (32) which is movable axially within the housing to effect turning movement of the steerable wheels. The member (32) has an externally threaded screw portion (40). A ball nut (72) is disposed in the housing (30). The ball nut (72) extends around the screw portion (40) and has an internal thread (90). Balls (98) are disposed between the internal thread (90) on the ball nut (72) and the externally threaded screw portion (40) for transmitting force between the ball nut and the screw portion to cause axial movement of the member (32). An electric motor (60) provides a drive force to move the member (32) in response to rotation of the steering wheel (11). Gearing (112, 114) transmits the drive force of the electric motor (60) to the ball nut (72).