Picture in your mind an automobile.
Now, what’s the first thing that pops into your mind? Isn’t it the body? The color. The chrome. The length… Right?
After that, we think about the interior, the upholstery and maybe even the all-important engine compartment.
Hardly anyone would visualize a differential or a leaf spring. In fact, most people don’t know the difference between a brake pad and a brake drum.
Why is that?
Probably because “what’s out of sight, is out of mind.” There is a whole other dimension to your vehicle that goes unnoticed because it’s hidden away under a glitzy exterior.
What’s the name of this hidden realm?
We’re talking about the chassis… a French word which literally means “frame.” The chassis is basically everything on your automobile from the ground up to where it meets the body.
An automotive chassis is made up of 4 components:
- Vehicle Frame
The frame of any vehicle is the base upon which every other critical part of the vehicle is anchored – the engine, the transmission and, of course, the body.
- Wheels and Tires
After energy and torque are created, it’s up to the wheels and tires to create the traction necessary for forward motion.
- Steering Works
Everyone knows what a steering wheel is, but there’s more to it than meets the eye. Deep down in the bowels of your chassis is an intricate weave of connecting arms and linkage that guides your wheels and helps maintain control.
- Suspension Systems
Your suspension is the middleman between you and the road. It’s in charge of how your vehicle responds to road conditions.
If the road dishes up rugged conditions, your suspension transforms the bumps and dips into cloudlike smoothness.
Here’s a brief overview of the primary function of your suspension system
Your suspension system basically has one very important job: Controlling the ride quality of your vehicle.
There are 2 tools that your suspension uses to smooth out your ride: springs and dampers. Let’s take a look at how they work.
There are 3 basic types of springs used on modern automobiles: coil springs, leaf springs and torsion bars.
Coil Springs: A coil spring is basically a heavy-duty strip of metal that has been wound around to form a spiral or helix.
Leaf Springs: A leaf spring is a stack of steel strips, called leaves.
Torsion Bars: Instead of flexing or compressing, a torsion bar absorbs energy by twisting. They are primarily used for front-end suspensions of all types of vehicles.
- Dampers (Shock absorbers)
Without a shock absorber, your vehicle would never stop bouncing. It’s the job of the damper to make the ride of your vehicle as bounce-free as possible.
The different types of suspensions
There are 2 basic types of suspension systems: Dependent and Independent. Let’s take a closer look at the unique characteristics of each system.
- Dependent suspension systems
On a dependent suspension system, the wheels on the left and right side of the vehicle are connected by a solid axle that spans the entire width of the frame.
Both wheels are linked to this single beam, and respond to road conditions by working together as a pair. Because of their ruggedness, dependent suspensions are often used on heavy-duty trucks, SUVs and rear-wheel drive cars.
- Independent Suspension System
An independent suspension system does not use an axle to connect both wheels. Consequently, the wheels react separately to road conditions.
Compared to a dependent system, an independent suspension provides better ride quality.
But here’s the thing…
If you gain better ride quality, you sacrifice the spring rate. And the reverse is true… increase the spring rate,* and you sacrifice ride quality.
*Increasing the spring rate does not increase the GVW