All vehicles on the road have some form of shock absorber. They are normally located on the front and rear wheels or axels of the vehicle and are connected to the total vehicle suspension system – tyres, springs, chassis and their linking components.
Their primary function is to keep the vehicle’s wheels in contact with the road.
Secondary functions are to ensure more accurate control and steering of the vehicle and to correct phasing (the movement of the suspension).
Some newer cars have struts instead of shocks. Struts are compact and allow for lighter vehicles and more interior room. They not only control the up and down movement of the tyre, but contribute to the steering’s pivotal rotation.
How shocks work
Shock absorbers slow down and reduce vibration by turning the kinetic energy of the suspension movement into heat energy, and then dispersing this heat energy through hydraulic fluid.
Shock absorbers work in two cycles: the compression cycle and the extension cycle.
When the wheel travels upwards causing the spring and shock absorber to shorten, the shock absorber is said to be in COMPRESSION STROKE.
When the road wheel starts to move back down, the shock absorber is lengthened and said to be in REBOUND OR EXTENSION.
A typical car or light truck will have more resistance during its extension cycle than its compression cycle. The faster the suspension moves, the more resistance the shock absorber provides. This enables shocks to adjust to road conditions and to control all of the unwanted motions that can occur in a moving vehicle, including bounce, sway, brake dive and acceleration squat. Are all shocks the same?
“Shock absorber” is a common term used for all shocks but there are various types:
- Standard telescopic shock absorbers,
- McPherson struts,
- Spring seat shock absorbers, and
Replacing your shocks at regular intervals will help keep your car performing like new, but choosing the right shocks can make a big difference. Today the design and manufacture of shock absorbers is a high technology, precision industry.
Gabriel SA manufactures shock absorbers, MacPherson struts and strut cartridges (as well as gas springs and uprated coil springs) from its Cape Town plant in Retreat – a state-of-the-art facility housing its own research and engineering facilities. Prototypes are assembled, tested and re-tested here by qualified engineers under laboratory as well as actual operating conditions. The Gabriel name has become synonymous with the highest standard of quality.