Suspension Theory 101

Sway Bar (Antiroll Bar)
A sway bar works under the same principal as a torsion bar, resisting energy by introducing energy against energy, (torsional) strength. The purpose of a sway bar is to eliminate body roll during cornering. As a vehicle begins to turn left or right, it is creating lateral energy and weight transfer. In doing so, as a truck turns, the weight transfers to the opposite side when it is turning. If the truck is turning left, the weight is unloading the left side of the chassis and transferring or loading the weight to the right side. As the truck turns to the right, the chassis is being unloaded on the right side and transferring the weight, loading the chassis on the left side. As the weight is transferred from left to right, or right to left, the chassis is loaded and unloaded from side to side. To increase the cornering and handling performance, a sway bar will eliminate the majority of the body roll, contributing to a flatter corner.

A sway bar is U-shaped with flattened ends and holes drilled in them. Sway bar endlinks are used to connect the sway bar to the control arms or axlehousing. The endlinks will transfer the weight from one end to the other by twisting (wrenching) the sway bar arms in opposite directions of one another. Torsion energy is the same action as ringing out a wet towel. The length of the arm from the bend to the end is where the strength comes from. The shorter the sway bar arm length, the stronger; the longer the arm length, the weaker the torsion bar.

Airbag Suspension
We have seen many of the traditional lowered 4/6 to 5/7 dropped trucks going to the next level and getting slammed, where you lay the framerails on the ground. This is done with an airbag system.

By removing the factory (front) coil springs and (rear) leaf springs from the truck's original factory suspension, airbags are installed to support the truck and adjust its ride height with the flip of a switch. Using an onboard compressor for its air source and a holding tank for its supply, the solenoids, the valves, and the air lines transport air, pressurizing the airbags, which replace the truck's traditional springs. A four-link system can be installed to keep the rearend located under the frame. Up front, the airbags are sandwiched between the upper and the lower control arms. When purging the air from the front airbags, the geometry will change as the wheel and tire travel upward, following the geometrical arch, tending to tuck themselves inside the front wheelwells. Airbags are located on all four corners of the suspension system. Changing the airbag pressure will adjust the truck's ride height accordingly.

Suspension improvements are made possible by the advanced technology of today's aftermarket manufacturers creating cutting-edge suspension components that will improve a trucks handling and ride height capabilities.