How does a shock absorber work for trucks?
The shock absorber for this task requires a different degree of damping of compression (jounce) and extension (rebound) than a shock absorber designed for a lightweight sports car with an independent suspension system.
The gravity of the situation
Strangely enough, despite their name, shock absorbers don’t absorb shocks. In reality, that is the job of the springs in a vehicle’s suspension system. As a wheel encounters a bump, the wheel moves upward, compressing and storing the energy of the bump into the spring. This compression is actually what absorbs the shock of the bump.
But now that the spring is compressed, it contains potential energy that must be released. The spring does this by bouncing back to its original uncompressed length, at the same time pushing the vehicle’s body upward. In an example of the old adage “what goes up, must come down,” gravity pulls the weight of the body back down, recompressing the spring. If the shock absorbers are worn, the vehicle ends up bouncing its way down the road after every bump until all of the energy is used up. In the worst cases, this bouncing can actually pull a vehicle’s tires off the ground, making the vehicle uncontrollable.