Parts of a Rack and Pinion Steering System (and Their Functions)
Rack and pinion steering systems are found in vehicles with or without power steering. Most modern cars have power steering, so you can assume they also have a rack and pinion steering system. Any car, SUV, or light truck you see on the road probably has rack and pinion steering.
These components make it very easy to turn the steering wheel because they absorb rotational kinetic energy and convert it into linear kinetic energy, which allows the wheels underneath the vehicle to turn with ease. Common Parts and Their Functions
Basically, the rack and pinion are two gears that form a gear set. These gears are housed inside a metal tube. You can see the rack on either side of the tube.
There is also a part called a tie rod that holds both ends of the steering rack together and connects the control arm to the spindle. The role of the tie rod is to transfer the force of the steering rack (or steering center joint) to the steering knuckle. This is done by connecting the tie rods to the handlebars, which causes the steering wheel to rotate when you try to turn it with your hands.
The pinion is also a component that contributes to this process. You can see the pinion connected to both the steering shaft and the rack. The connections are made at both ends of the pinion. Essentially, the pinion connects the steering shaft and the rack.
When you turn the steering wheel, these rotational movements are absorbed by the steering shaft and transmitted to the pinion that is connected to it. As the pinion rotates, so does the rack that is connected to it. So, the rotation of the steering wheel moves the pinion, which in turn moves the rack. In a power steering system, the rack is designed slightly differently. The rack also has a cylinder and a piston. The piston and rack are connected to each other, and the piston has fluid ports on either side.
High pressure servo fluid enters the piston from one side, vigorously moving it. This also moves the rack, creating the power assist function of the system. Other Components
The rack and pinion are the two main components, but what other components in this steering system are worth mentioning? Well, we mustn’t forget the power steering fluid, the pump and the hoses.
The power steering pump (vane pump) generates the hydraulic pressure needed for the power steering fluid to work its magic on the pistons and rack. The hoses obviously carry the steering fluid from one component to the next in the steering system. And of course the power steering fluid converts rotational energy into linear energy.
Conclusion
The rack and pinion is responsible for the number of revolutions required to move the steering wheel from its leftmost stop to its rightmost stop. In most cases, it will take 3-4 revolutions to move from one stop to another.
The number of teeth on the gear is what really makes a difference here. Additionally, having the rack closer to the center reduces the force required to turn the steering wheel. This is often seen in sports and luxury cars. However, on all other vehicles, it’s just the standard number of teeth per inch on the steering rack.
If you need to replace these components, your mechanic will likely replace them with a new rack and pinion that’s equivalent to the old one.
