Repair 7

Truck Suspension Components

All types of automobiles rely on a suspension system to attach the body and frame of the vehicle to its wheels. Suspensions serve the important purpose of keeping the wheels firmly planted on the ground. They also make driving more comfortable by reducing shock. Truck suspensions are similar to car suspensions but use larger components that can handle the increased weight or survive the stresses of off-road driving.

Springs

Coil springs serve as the basis of most truck suspensions. The springs rely on a very simple mechanical principle of compression to resist the shocks that the wheels experience. Springs absorb energy to push the wheels down and keep the frame of the truck level.

Struts

Struts are shock absorbers that run through the center of a truck suspensions coil springs. They contain compressed gas or liquid that can absorb energy and keep the trucks body level, much like the coil spring. Struts differ from coil springs in that they include multiple mounting points for attaching to the truck frame and other suspension components. A strut can resist force in an up-down direction, but also from side-to-side. Struts are stronger (and larger) than the shock absorbers on small cars, making them ideal for trucks when paired with a coil spring.

Sway Bars

A trucks sway bar is a relatively large piece of its suspension. Sway bars connect two wheels at the same end of the truck. They are not solid, but instead include a torsion spring that absorbs energy as the trucks makes turns, when force is applied to the wheels unevenly. Sway bars help prevent the body of the truck from leaning as the driver executes a turn and subjects it to sideways (torsional) force.

Tie Rods

A trucks tie rod is a solid metal shaft that runs the width of the front suspension. It attaches near each wheel and engages the steering mechanism. Since the steering components, like the Pitman arm and drag link, are not part of the suspension structure and dont attach directly to the wheels, the tie rod links the steering shaft to the suspension so that the trucks driver can control the wheels independent of the movement of the suspension.

Control Arms

A control arm attaches each wheel to the trucks frame directly. Two control arms form a double-wishbone suspension, which attaches to the wheel via a ball joint that allows the control arm to pivot. Steering linkages affect the motion of the control arm to apply the force that turns the wheel.