What component replaces the coil spring and serves a similar purpose in a suspension system?

The component that replaces the coil spring and serves a similar purpose in a suspension system is a torsion bar. Torsion bars are designed to provide the same function as coil springs, which is to support the weight of the vehicle and absorb shocks from the road. They work on the principle of torsion, where the bar twists and absorbs energy when the suspension moves, allowing the wheels to respond to bumps and uneven surfaces.

Torsion bars also enable adjustability in the suspension system, which can help maintain vehicle height and ride quality. This is particularly useful in applications where vehicles may carry varying loads.

The other components listed, such as shock absorbers, strut assemblies, and sway bars, serve different functions in the suspension system. Shock absorbers primarily control the rebound of the springs and dampen the oscillations from the suspension movement. Strut assemblies include a coil spring and serve as a structural part of the suspension. Sway bars help reduce body roll during cornering but do not replace the suspension spring's role in supporting the vehicle's weight. Each of these components plays a distinct role, which is why the torsion bar is correctly identified as the replacement for the coil spring.