KEEPING A GRIP ON THE ROAD

An incorrectly operating wheel will lead to extended stopping distances and inefficient driver assistance systems

The maintenance of shock absorbers in good condition is essential for the operating safety of automotive vehicles and improves the driving comfort of the vehicle.

The vibrations which occur in the vehicle wheels and body are eliminated or significantly reduced by shock absorbing elements.

Their task consists of damping the vibrations generated in the vehicle’s suspension system. The damping consists of the reduction of magnitude of the vehicle wheel and body (vibration amplitude) and in the reduction of their duration.

The hydraulic shock absorber is the typical and commonly used shock absorbing element.

The correct functioning of the suspension system is essential in increasing the adhesion of the vehicle to the road surface, because it increases the duration of vehicle contact with the ground when travelling across uneven surfaces.

The service life of the vehicle as well as the functioning reliability of other subsystems, passengers’ comfort, and the condition of transported goods is also significantly affected. Therefore, the determination of shock absorber condition is crucial for correct vehicle operation.

It is ironic that often when a vehicle’s braking system is inspected, it is not done in line with the testing of the wheel’s traction.

No matter how effective a vehicle’s brakes are, it is useless if the wheels cannot effectively grip the road. An ineffective wheel will lead to extended stopping distances and inefficient driver assistance systems, such as ABS and ESP.

In turn, a wheel can become counter-productive, bouncing will persist, and its shock absorber will be damaged.

AutoTest says that unfortunately, most inspections are only conducted visually and therefore 50 percent of wheels are not properly assessed. It states this will continue to be a common problem, unless shock absorber testing becomes an integral part of the inspection process.

Shock absorbers have a limited life span. AutoTest says that on average, 10 percent will fail by five years as indicated in the table and graph. It is therefore critical to conduct shock absorber tests in line with all visual inspections.

The suspension system plays an important role in the safety and drivability of a vehicle.

To maintain the system in a safe condition, you