An apparatus (10) for use in turning steerable vehicle wheels (12, 14) includes first and second piston and cylinder type hydraulic motors (32, 34) which are connected with a central portion of a vehicle. A steering control valve (24) is operable in response to manual rotation of a steering wheel (18) to effect extension and contraction of the first and second hydraulic motors. A rack and pinion steering gear (110, 114) may be connected with a piston rod (86) of one of the hydraulic motors (32). A secondary control valve (200) may be provided to effect operation of one of the hydraulic motors to a greater extent than the other hydraulic motor.