Steering & Suspension

If your steering or suspension has developed a fault, it will soon become apparent to both the driver and to the passengers. The car may feel as though it is drifting or wandering across the road and the steering may feel wobbly or less positive than it did. Maybe you can feel (and hear) every single crack in the road surface, and when you hit bump or pothole, your car scrapes the ground or bounces around afterwards. These are all indications that you need to get your steering or suspension checked before any further damage ensues to your brakes and tyres, or you fail your next MOT test.

The AutoMend network of car and van maintenance and repair experts is on hand to help you out wherever in the UK you happen to be. Our access to over 9,000 garages, among them mobile mechanics are experts in diagnosing and repairing defects in your suspension system or your steering mechanisms. We will give you contact details of all your local mechanics once you have given us a few simple details. We need to know where you are (your post code and location), what vehicle you need help with, and what help you need. In return, you will get a list of all the local businesses who specialise in your type of repair, and how far from you they are located. All you need to do is to call them up to discuss and make an appointment with an expert mechanic, or you can ask for free no-obligation online quotes for the work. It couldn’t be easier to find the expertise you need at a price you can afford through the AutoMend network.

HOW THE CAR & VAN STEERING SYSTEM WORKS

As a driver, your interface with the steering system is the steering wheel, which turns the front wheels of the vehicle when you want to change direction – that’s the simple part. Between the steering wheel and the car’s wheels there are a whole host of complex and precise mechanisms which allow you to control the car’s direction with ease and precision. The aim of the steering system is to take the circular motion of the steering wheel and translate it into a swivelling motion which allows the car’s wheels to turn while running along the road.

The steering wheel sits on the steering column, which in turn is connected to a steering shaft, which reaches down and out through the bulkhead of the driver’s compartment. The steering shaft is usually set up so that in the event of a collision, it will collapse thus preventing the driver being seriously injured by a collision with a rigid shaft. The steering wheel itself will probably contain one or more air bags for further collision protection.

Most modern cars have hydraulic power steering, which is the first point of contact for the steering shaft. The steering shaft runs into a rotary valve, which is assisted by hydraulic forces to turn a pinion gear attached to the steering rack (hence the name ‘rack and pinion’ for this type of steering). The steering rack consists of a toothed metal bar running parallel to the axle connecting the front wheels. The teeth of the steering rack mesh with the teeth of the pinion gear. Turning the steering wheel turns the pinion gear, which makes the steering rack move from right to left, thus turning rotary motion into side to side motion.

At the ends of the steering rack are the tie rods, each of which connects to a steering knuckle. The steering knuckles ensure that when the wheels on each side of the car turn to the left or to the right, they are parallel to each other.

HOW THE POWER STEERING WORKS ON YOUR VEHICLE

Most power steering systems use a hydraulic pump which is turned via a drive belt connected to the engine. This pump is situated on the steering shaft and is used to pressurise hydraulic fluid in a closed system, which assists the rotary valve to turn the pinion gear. The hydraulic pressure enables the driver to turn the car’s wheels with little physical effort on the steering wheel.

There are also electric power steering systems available which use a computer-controlled electric motor on the steering shaft to assist with turning the pinion gear. Earlier electric systems gained a reputation for distancing the driver from feeling the road, but they are under constant development and becoming more popular. They need less maintenance than hydraulic power steering and are less polluting as they don’t need a hydraulic pump or hydraulic fluid to operate.

Whichever system you have, you need to ensure it is operating correctly otherwise you may find the steering becoming heavy. If your power steering has begun to feel inefficient or it is making odd noises, get it checked out by an expert from the AutoMend network.

WHAT A VEHICLE SUSPENSION SYSTEM DOES

If all roads were perfectly flat and smooth, your car would not really need a suspension system. However, even newly-surfaced roads have bumps and uneven areas, and without suspension a driver would soon become very uncomfortable indeed. The aim of suspension is to put a flexible connection (a spring) between the car’s chassis and the wheels. This enables the wheels to run along the road, however rough the surface, while the vehicle has a comparatively smooth ride above them, with most of the bumps being absorbed by the springs.

The suspension system also has to enable the wheels to be steered while running over the road surface. The wheels need to not only turn from left to right, but they need to be able to go up and down as well. This movement is achieved by using a ball joint – it operates a bit like the ball and socket joint you have in your hips. Ball joints allow free movement and are essential to ensure the steering and suspension systems operate closely together.

THE BASICS OF A VEHICLES SUSPENSION SYSTEM

Springs

The springs are the primary part of the suspension system – they sit between the wheels and the chassis. The springs keep the wheels on the road and take some of the impact of the bumps and potholes. However, springs alone cannot absorb all the shocks – without extra help, the vehicle would bounce up and down after every impact and swing around. To keep the vehicle stable and the ride smooth you need ...

Shock absorbers

Shock absorbers provide extra protection for the car’s suspension system. They avoid the springs having to compress or extend with too much vigour, and they damp the movement of the springs, making the car more stable more quickly.

Wishbone

The wishbone (also called the swing arm or carrier arm) holds the shock absorber and spring to the chassis via a rubber bush to reduce road noise. The wishbone is crucial in that it ensures the wheels sit at the correct angle to the road. The rubber bushes can wear with age and should be replaced, and if the wishbone itself is not operating correctly, uneven tyre wear can ensue, and there is a risk of damage to the braking system.

There are a whole series of struts, dampers, bushes and other types of protection for the suspension, and they can all wear out with time. A worn suspension can be a killer as steering and braking (especially at speed) will be affected. If you suspect any problems with your suspension, get it checked out as soon as possible, it could save your life.

WHEN TO KNOW THE SHOCK ABSORBERS NEED REPLACING ON YOUR CAR

Unlike many car components, there is no specified lifespan or mileage limit for shock absorbers. Their longevity depends on the types of road surface you drive on – the smoother the surface, the longer your shock absorbers will last. The rougher the surface, the quicker they will wear out.

There are a few indicators that you can check for yourself to see if your shock absorbers are doing their job properly, or if it’s time to get your local AutoMend garage to check them out for you. If you experience any of the following, your shock absorbers may need replacing:

Driving experience
  • Your car feels as though it’s swaying gently from side to side even on a smooth straight road.
  • Every small bump generates a throbbing noise.
  • Hitting a pothole or bump makes the car crash down rather than riding over it.
  • The vehicle rocks after the impact, or a knocking noise is heard.

Push test

Either push down on the back, front or corner of your car (or sit on it and get up again). The car drops quickly and rises quickly and unevenly.

Visual check

If you’re flexible enough, crawl under the car and look under the wing. The piston may show rust, although it’s hard to see if the piston is rubber-covered. A rusty piston can mean an ineffective shock absorber.

CHECK THE SHOCK ABSORBERS ON YOUR CAR OR VAN BEFORE TOWING

This is an important check – before connecting anything to your tow bar, and especially if the trailer is a caravan or is going to carry a heavy load, check that your shock absorbers are fully operational.
Weakened shock absorbers will affect the steering and braking stability of your vehicle, making skidding more likely. If you attach a heavy weight to the tow bar, this will exaggerate the problem because the front tyres will have less grip on the road.

For your own safety and that of other road users, get your suspension and steering checked out by a trustworthy expert before embarking on a journey with a trailer or caravan. Contact your nearest AutoMend network member for a friendly service at competitive prices.