Steering Gear - Power: Description

Gear is variable ratio recirculating ball bearing type. Steel ball bearings work as a rolling thread between steering gear worm shaft and rack-piston nut. Worm shaft is supported by a thrust preload bearing and 2 conical thrust races at lower end, and a bearing assembly in adjuster plug at upper end. This design provides continual spring loaded pressure on worm shaft to prevent loss of thrust bearing preload for life of gear.

Adjuster plug provides initial preload adjustment and service adjustment when servicing gear. As worm shaft is turned right, rack-piston moves upward in gear; turning worm shaft left moves rack-piston downward in gear. Rack-piston teeth mesh with sector which is forged as part of pitman shaft. Turning worm shaft turns pitman shaft which turns wheels through mechanical linkage.

NOTE: Model 605 (Small Gear) is similar to the model 800-808 (Large Gear) described above with the following exceptions:

Small gear has a round side cover held in place by a retaining ring while large gear has a rectangular side cover held in place with 4 bolts.
The worm and rack are directly mated rather than separated by recirculating ball bearings as in the large gear.
Thrust bearing adjustment is at lower end of gear by hex -driver instead of at stub shaft end with spanner.