Wheel balancing and steering wheel vibration

Hold the wheel on a steady, safe stretch of road and notice the speed at which the shake starts. A vibration through the steering wheel that appears at a certain speed and then fades again is the classic sign that a front wheel is out of balance.

Balancing fixes that by adding small weights to the wheel, but it is not the only possible cause, so it is worth knowing what else to consider before you book.

Why does my steering wheel shake at certain speeds?

A wheel and tyre are never perfectly even in weight all the way round. A heavy spot makes the wheel hop slightly as it spins, and at a particular speed that hop lines up with the suspension and you feel it in the steering.

Front wheels send the shake to your hands, while rear wheels tend to be felt through the seat or floor. Tyres lose and shift their weight distribution as they wear, and a lost wheel weight can bring the problem back. Kerbing a wheel or picking up mud inside an alloy can also upset the balance, which is why the shake sometimes appears out of nowhere.

What does wheel balancing involve?

The wheel and tyre are fitted to a balancing machine, which spins the assembly and shows where the heavy spots are. Small weights are then clipped or stuck to the rim to even things out.

It is normally done whenever a tyre is fitted or refitted, including after a puncture repair. It is a quick job, but the machine needs a clean, undamaged wheel to give a true reading. If the wheel is bent or the tyre is damaged, balancing will not cure the shake, and the garage will say so rather than adding weights for the sake of it.

• Wheel removed from the car and mounted on the machine
• Old weights and dirt cleared away
• Assembly spun to find the heavy spots
• New weights fitted, then the wheel refitted and nuts tightened

Could it be something other than balancing?

Yes. A bent wheel, a bulge or flat spot in a tyre, loose wheel nuts, worn suspension or steering parts and a tyre that has come apart internally can all cause vibration. Brake discs that have worn unevenly tend to cause a shake only when you brake.

That is why the symptoms matter. A vibration at a steady speed points towards balance, one that appears when braking points towards the brakes, and a wobble that gets steadily worse needs attention straight away.

What will the garage check first?

We start with the simple things: wheel nuts, tyre condition, pressures and any visible damage. We then spin the wheels on the balancer, which also shows up a bent rim or a tyre that is not running true.

If balancing does not cure it, we look at the suspension and steering joints for play. What the work involves, and the cost, depends on what is found, so ask for a quote once the car has been inspected.

When should I stop driving with a vibration?

Stop and have the car looked at if the shaking is severe, getting worse, or comes with a pulling sensation, knocking noises, a bulge in a tyre or a burning smell. A sudden new vibration after hitting something in the road should not be ignored.

A mild shake at one speed is less urgent, but do not leave it for months, as it wears tyres and suspension parts. Automaster is a garage at Longcombe Cross near Totnes, and you can ask us for a balancing check and a quote.