To some, off-road suspension systems become important when they need to find ways to fit bigger tires and truck bumpers on their truck or increase ground clearance. Yet fit is only half of the story. An off-road suspension is a critical component of your off-road truck and important for more than just giving you lift. How different suspension systems perform must also be taken into consideration to get the function and durability you need.
Solid Axle Suspension Systems
Solid axle suspension is the oldest and simplest suspension system used on off-road trucks today. It consists of one solid axle attached to the truck with leaf springs. The whole axle moves with the vehicle. Many truck owners favor this kind of setup because of the way the leaf springs work to both support the axle and give lift at the same time.
Leaf springs can also be adjusted by adding leafs of various lengths and thicknesses to improve performance. It is a highly functional, yet uncomplicated system that is great for many types of off-roading.
Solid Axle Variations - Radius Arm and Four Link
Two variations of the solid axle design are radius arm and four-link suspensions, which both use coil springs instead of leaf springs. Radius arm suspension is a more compact solid axle system; however, the coils only support the weight of the truck. The axle is mounted to one of two radius arms which are mounted on the frame and pivot to allow the axle to move up and down.
Four-link systems are a variation of the radius arm suspension and come in a parallel or triangular setup. The four-link design removes the pivot point of the radius arm, replacing it with two suspension links that have four attachment points on the frame and pivot points at the axle mount.
The axle is centered by the coil springs and a separate track bar. The main benefit of this suspension system is a smoother ride because of the location of the pivot points. The triangular four-point setup is designed for positioning the links at greater angles than the parallel setup, which eliminates the need for the track bar.
Twin Traction Beam Suspension Systems
The twin traction beam (TTB) suspension is a hybrid system that is both solid axle and independent at the same time. It is available with either leaf or coil springs and incorporates two solid axles set diagonally from the frame to the wheel and pivot in the center.
The system is extremely durable, making it beneficial for speed desert racing; however, it is easy to throw the steering or alignment off when these systems are not properly installed. This can result in complaints of bump steer and uneven tire wear.
It is important to consider exactly how you will be using your off-roader before you purchase this type of system. Think about how well this type of suspension will work with your tires and truck winch bumpers while racing in the desert.
Independent Suspension Systems
Full independent suspension systems are basically designed to offer a comfortable ride on pavement by giving each wheel the ability to move on its own. Total four-wheel independent systems are not used off-road very frequently. Rear wheel independent systems are common on rear-engine desert racing vehicles, while front wheel independent systems are customary on many off-road racing vehicles. In both instances, these systems are chosen for the easier ride they provide.
Independent front wheel systems using an unequal A-arm design are effective for keeping the wheel hubs parallel to the ground as the upper arm is shorter than the lower one. The main drawback with this system is fitting the A-arm system on smaller vehicles. Longer A-arm systems are available and offer more travel; however, they are more expensive in comparison to TTB systems.
With all that said, which one you should choose for your prized off-roading truck? That is a decision you should make based on the kind of off-roading you do, how much space you have for a suspension system and any other goals you have in mind. Consider the way each of these systems function as well as the pros and cons of each, not just how much lift they can give you for big tires and aftermarket steel truck bumpers!