Car suspension is what saves you from having your flesh jolted from your bones when you’re simply driving down the road. It’s an intricate combination of springs, shock absorbers and joints that attach the wheels to the vehicle. It's also integral to the car’s road-holding or handling, road noise reduction and braking efficiency.

It works through ensuring that most of the tyre is in contact with the road surface for as much of the time as possible, especially when cornering where forces at work want to lift or tilt the vehicle, thereby potentially compromising on traction and steering.

Another aspect of the suspension is in containing any cargo or loads, ensuring that the added weight doesn’t infact damage the vehicle in transit.

Inside A Suspension System

There are myriad designs for suspension systems across brands and individual cars. Indeed, the suspension design at the front of a ride may be completely different to that at the rear.

Leaf springs were around since the early Egyptian period and the design was so good and simple, it’s still in use today on some vehicles. Coil springs were invented in 1906 and make up the majority of car systems today, although leaf springs are sometimes used on the rear of larger vehicles.

But there were drawbacks with both these designs in terms of how they reacted to an uneven surface, bouncing about and therefore affecting the ride, but also taking the wheels off the ground. In 1901, Mors of Paris came up with the concept of shock absorbers.The immediate advantage of these was that they would absorb an impact, but not react quite so enthusiastically, keeping the tyre grounded. This became more and more important as cars increased in speed.

But it was the introduction of independent suspensions for front and rear that really made the breakthrough, as the demands on both ends of the car are so different in terms of weight bearing, steering and braking.

These days, more often than not, shock absorbers use either pneumatics or hydraulics to take the punishment meted out. In most cases, the pressure is converted by the oil or air into heat, which is then dissipated.

Understandably, these quite complex units take quite a beating and eventually wear out, or spring a leak. Not only this, the springs also take a pounding, as do all the linkages and joints involved in attaching the wheels to the car. As there’s substantial movement to all these components so it behoves any owner to have this system comprehensively checked out from time to time.

Checking Your Own Suspension

In general terms, it is easy enough to observe shock absorbers by noticing the car roll when cornering. Also, if there are any strange creaks, groans or clunking when cornering or braking, these should be checked out immediately and not left un-investigated.

You can also measure the suspension when the car is stationary. Park the vehicle on a level surface, then walk around it and push down heavily on each corner. Feeling how easy it is to compress the shock and then watching how the car returns to normal is a big giveaway; if the car bounces easily, rather than reverting firmly with no bounce, it’s very likely your shock absorbers are past their best and need replacing.

Getting the car up on a ramp or crawling underneath with a torch is also a good idea, to check if there is any noticeable oil leakage. Whilst there, examine any linkages, particularly with a lever and check that all the nuts and bolts are sound. If the shock absorber doesn’t show signs of a leak but is excessively corroded, it should be replaced. Always replace a pair and not just one.

The springs too can shatter over time but lay undiscovered in their housing, so make sure they look happy and healthy and aren’t too corroded either. Your car suspension system takes a lot of pounding in all weathers, and water or even road salt will take a long time to leave unless removed, making corrosion a big issue with the parts you can’t normally see.

Another tell-tale sign of a compromised car suspension is patchy tyre wear, signalling intermittent contact with the road.

If you have any doubts, there are any number of garages who will give your pride and joy a free, professional once-over, but it really isn’t hard to do yourself if you know what to look for and take your time.