The worm gear and the pitman gear are components within a recirculating ball steering gearbox.

Worm Gear

A gear consisting of a shaft with a spiral thread that engages with and drives a toothed wheel.

Pitman Gear

A component in the steering system of a vehicle that converts the angular motion of the steering column into linear motion needed to steer the wheels.

Recirculating Ball Gearbox

An older style of steering gearbox whose main components are a worm gear on the steering shaft, a ball nut that moves on ball bearings up anddown the shaft as the worm gear turns, and a sector gear thatengages with the ball nut and transfers steering inputs to thesteering linkage.