Decades ago, sports cars established this type of system as desirable due to its precision and response, and today most passenger vehicles have it as standard equipment.
Glossing over reference to rack-and-pinion steering in specification charts is easy to do. We tend to dismiss it because that's what all vehicles seem to have. (However, other systems do remain on the market.) Understanding rack-and-pinion steering and its benefits will contribute to appreciating what makes a Subaru, a Subaru.
With the action of turning the steering wheel to cause a vehicle to change direction, a number of components come into play. Although enhanced by other systems, here are the basics of rack-and-pinion steering:
- The steering wheel rotates the steering column.
- The teeth on the pinion gear at the end of the steering column engage with teeth on a rack in the steering gear assembly.
- The rack assembly moves the tie rod assemblies to which it's connected.
- The tie rod assemblies push or pull on the steering knuckles connected to the front wheels, causing the direction in which the wheels are pointed to change from one side to another.
The point of the steering system is to transfer the driver's rotational force into a lateral one that alters the direction in which the vehicle is traveling. The steering force from the teeth in the rotating pinion gear becomes a lateral force via the gear teeth on the rack.
All Subaru steering systems have power assist. Hydraulic pressure provides added boost at low vehicle speeds to help the driver turn the steering wheel. Pressure is reduced at higher vehicle speeds.