Shocking news about shock absorbers
JUST like brakes and tyres, shock absorbers don't last forever. The fact is that they will wear out gradually and become, imperceptibly, less effective.
Unfortunately, because shock absorbers are "out of sight" it is quite easy for them to slip into the "out of mind" category.
But shock absorbers play a major role in the car's handling and safety. No matter how good the tyres are, they won't be able to do their job if the shock absorbers are worn out.
The shock absorbers dampen the effects of the springs and help push the tyres down onto the road surface.
Obviously as the shocks wear, their ability to do this job reduces over time. The end result being that your car's tyres have less contact with the road.
This lifting of the tyre contact patch affects the level of road grip and will therefore have an impact on steering, cornering and braking. It can also make the car more prone to aquaplaning in the wet because the water isn't being properly squeezed out by the tyre tread. The tyre can ride up onto a thin layer of water instead of the road and you can find yourself sliding across the road.
Research commissioned by leading shock absorber manufacturer Monroe found that a car fitted with effective shock absorbers will stop two metres more quickly than the same car fitted with just one worn shock absorber.
The German vehicle inspection agency TUV found that, in a simulated emergency braking test, a car fitted with four effective shock absorbers travelling at 50kmh along a straight, dry, uneven road stopped two metres more quickly than a vehicle with just one worn shock absorber.
Further tests were carried out to assess the effects of worn shock absorbers on safety systems such as anti-lock braking (ABS).
And, tests show that the difference between good and bad shock absorbers is even more pronounced when the car is fitted with systems such as anti-lock braking.
A new VW Beetle with anti-lock brakes and Electronic Stability Control was put through an emergency braking test, firstly with 100% effective shock absorbers and then with shock absorbers that were 50% worn. The test was carried out at 80kmh on a straight road where a lane was blocked to simulate an obstacle.
The difference was a staggering six metres - more than 20% - with the worn shock absorbers severely affecting the car's safety systems.
So how do you know if your shock absorbers are worn out? Well as a guide if you have travelled about 30,000km your shocks may have used around 50% of their life. Remember that this is a guide only.
The wear rate of the shock may vary and can be affected by types of road you drive on. Other signs that the shocks aren't working as well as they should also include:
- Your car seems to take longer to stop
- Vibrations in the steering wheel
- Nose-diving under braking
If you are experiencing any of these points or if you're not sure, get your shocks checked by an expert.
Remember, having fully efficient shock absorbers is an essential component to your car's road safety package.
Russell White's experience in the driver training industry spans more than 24 years. He is widely regarded as one of Australia's leading road safety advocates. His business offers the complete range of driver training and fleet management services, visit driversafety.com.au