Have you ever ridden in a car or truck that had a bouncy ride? If so, chances are the suspension was out of tune. A suspension that is not properly aligned can make for a very uncomfortable and even dangerous experience while driving.
Shop All Suspension Equipment Here
In this post, we will explore the different types of spring systems used in vehicles and explain how they work. We’ll also outline some tips to keep your suspension functioning properly. So, let’s get started!
Types of Spring Systems
There are four main types of spring systems used in modern vehicles: leaf springs, coil springs, torsion bars, and air springs.
Leaf Springs
Leaf Springs are used on vehicles with relatively few passengers, like sports cars and light trucks (a truck that weighs less than 10,000 pounds empty), leaf-springs are made of several metals or rubber flat strips arranged in a “V” pattern with each end of the leaf spring attached to an anchor point (usually on the frame of the vehicle).
In addition, the “V” shape of the leaves allows them to flex as your car moves; which is how they absorb energy and reduce the impact of bumps and dips in the road.
Pros
- Leaf Springs are very strong and sturdy, yet relatively light in weight
- Provide a surprisingly comfortable ride
- Easy to work on and install
Cons
- If not properly anchored, the weight of the vehicle can push down on one side of the spring and put excessive pressure on that leaf. This could cause it to bend or break
- Can rust if water can run along the length of the leaf and come in contact with metal parts
- If a leaf breaks, all of the tension from its partners goes directly into the frame/chassis which could cause significant damage
Coil Springs
The most common type of spring system found in vehicles today is the coil (or torsion) spring. Coil springs are made out of a continuous wire that is wound in a tight spiral pattern to provide support and flexibility in different temperatures. The ends of each coil are then anchored together to form a “coil pack.”
A number of these packs are then connected to an axle or suspension arm (hinge) with rubber bushings at each end. Coil springs have been used on vehicles for over 100 years starting with Alexander Wilson’s development for cars in 1904.
Like a leaf spring, a coil spring takes the form of a long metal strip. Unlike a sturdy and broad-leafed plant, coil springs are generally made from heavily coiled steel wire under high tension. One end of the coil is anchored to the frame while the other end either rests on top of or inside a metal bushing attached to an axle or another component on your vehicle.
Pros:
- Coil Springs are inexpensive and easy to repair/replace
- Easily adjustable and can be swapped out to accommodate a variety of loads
- Provide a smooth ride with consistent handling
- Coil suspensions usually have a minimum sag depth (distance between the fender and chassis).
Cons:
- Coil Springs lose energy quickly and thus offer very little protection over bumps and potholes
- More expensive than leaf springs, torsion bars, or air suspensions
- If one of these springs breaks, it can completely compromise all the others in its row or “bank”
Torsion Bars
Also known as torsion axles or torque bars, torsion bars are long steel bars that twist when torque is applied to them. Torsion bars are used to help reduce body lean during cornering and as a result, improve the handling characteristics of even heavy vehicles.
They are similar in shape and style to leaf springs as they are made up of a long metal bar with one end anchored to the frame and the other wrapped in a protective rubber or urethane cover. The part that wraps around the axle passes through a hole at one side of the steel center shaft and attaches to another anchor point on the vehicle’s frame. This part is typically covered by a protective boot.
Pros
- Relatively inexpensive compared to other suspension options
- The rubber covering protects the torsion bar from weather/road conditions
- Compact design does not take up much space under the vehicle’s frame
- Easy to install/repair
Cons
- Torsion bars don’t offer as smooth of a ride as leaf springs or coil suspensions
- Vibrations and noise can be transmitted through the body panels of your car, truck or SUV if they are not properly anchored
- If even one torsion bar breaks, others in its row may be affected as well
Air Springs
One type of spring system found on some luxury cars is air suspension. Some of the most well-known examples include the Mercedes S Class and BMW’s 7 Series.
An air suspension allows each corner of the car to be independently adjusted for height allowing drivers to keep their preferred level while cruising or when parking. Most suspensions use rubber or metal below to connect each side of the car with pressurized air supplied by the engine’s main cooling fan via hoses routed through the vehicle’s body.
Air springs work much like their cousins, leaf springs, but a major difference is that the tension in the air spring is supplied by a pressurized gas rather than a mechanical component. Air Springs use compressed air to create a lifting force that acts as suspension. A compressor will inflate and deflate these springs depending on road conditions or driver input.
Pros
- Provides great ride quality with minimal weight compared to other components
- Allows for independent adjustment of each wheel
- No sagging, which means a smoother ride over bumps and potholes
- The air springs provide automatic leveling of your vehicle
- Keeps the tires from hitting the body when turning corners or going over speed bumps
Cons
- Air Springs can be costly to repair/replace if they become damaged
- In cold weather conditions, the pressurized gas used for suspension may freeze up
- Oxygen sensors may be affected by increased pressure from the system (if you disconnect them)
- These springs are known to fail under extremely hot weather conditions; they can even explode if allowed to overheat.
So, what type of suspension system is right for you? If you’re still unsure after reading this article, feel free to reach out to us and we would be happy to help. We know suspensions inside and out and can steer you in the right direction for your vehicle and driving style. Happy trails!
