Manual Worm and Roller Steering

The manual worm and roller steering gear is used by various manufacturers. This steering gear has a three-turn worm gear at the lower end of the steering shaft. Instead of a sector or tapered peg on the pitman arm shaft, the gearbox has a roller assembly (usually with two roller teeth) that engages the worm gear. The assembly is mounted on anti-frictional bearings. When the roller teeth follow the worm, the rotary motion is transmitted to the pitman arm shaft, pitman arm and into the steering linkage.