The power ball and nut steering gears are widely applied to heavy duty trucks and jeeps like Isuzu, Styer and GM as well as cran

The recirculating ball construction results in a friction free contact between thenut and the worm. When the steering wheel turns to the left, the ball bearingsroll between the worm and the nut and work their way upward in the worm groove.When the ball bearings reach the top of the nut, they enter two ball guides andare directed downward into the worm groove at a lower point. When the steeringwheel is turned to the right, the ball bearings circulate in the opposite direction.

GM Saginaw 525 Manual Steering Box