Power Steering Gear Basics :
Before we get into diagnosing power steering problems, let’s quickly review the basics of how power steering operates. The rotary motion of turning the steering wheel is converted into linear (side-to-side) motion through the meshing of the helical pinion teeth with the rack teeth within the steering gear. This lateral travel pushes and pulls the tie rods to change the direction of the front wheels on the vehicle

The power assist is provided by a belt-driven, rotary-type pump and is controlled by an open center, rotary-type control valve. It directs pressurized fluid to either side of a piston located on the rack gear inside the steering gear housing.

Rotation of the steering wheel directs more pressurized fluid to one side of the piston than the other. This imbalance in fluid moves the rack gear in