Rack & Pinions & Steering Boxes

What Is a Rack and Pinion?

A rack is a circular gear, and a pinion is a linear gear. Together, they turn rotational motion into linear motion. Simple, right? In the automotive world, this is how spinning the steering wheel in a circle makes the wheels on your car turn left or right. If the rack and pinion aren¿t working properly, then steering your car becomes a challenge.

How Does a Rack and Pinion System Work?

The rack and pinion gears are enclosed in a long metal tube. That tube connects the racks to the axial rods on one end of the tube and the pinion to the steering shaft on the other. The rack and pinion system acts as a go-between, linking parts to turn the spinning motion of your steering wheel into the turning motion of your wheels.

That¿s a lot of mechanical bits moving with the steering wheel, and it takes a lot of force. Power steering systems make this process easier for the driver, and a hydraulic piston helps turn the rack and pinion gears. Manual steering systems offer no such assistance and have steering wheels that take much more effort to turn.

Does Every Car Have a Rack and Pinion System?

It all depends on the vehicle. Most cars, small trucks and SUVs have a rack and pinion system, but larger trucks or SUVs (including heavy-duty trucks and commercial vehicles) most likely will not have a rack and pinion system.

Instead, those vehicles have recirculating-ball systems. These systems use ball bearings that circulate around a worm gear to do the same job as a rack and pinion system: turning the wheels. However, they can better withstand the heavy load conditions of larger vehicles.