Steering gear shall be approved by the chassis manufacturer and designed to assure safe and accurate performance when a vehicle is operated with maximum load at maximum speed. If external adjustments are required, a steering adjustment mechanism shall be accessible. Changes may not be made in steering apparatus which are not approved by chassis manufacturer. There shall be a clearance of at least 2 inches between the steering wheel and cowl instrument panel or any other surface. Power steering is required and shall be of the integral type with integral valves.