All posts by mmechadmin

Wheel alignment and noisy tyres

It used to be on the earlier rear wheel drive cars with a solid diff and axle, that the only wheel alignment required was for the front wheels.

But that has all changed with the advent of front wheel drive and independent rear suspension. The rear wheels, like the front ones, also can go out of alignment. When they do, they wear unevenly which sometimes causes ‘ripples’ or ‘scalloping’ on the tread. This results in a noise that sounds like the wheel bearings are about to collapse.

The ‘ripples’ can actually be felt by lightly running a hand around the tyre tread. If you do this yourself use gloves to protect your hands as there might be sharp objects wedged in the tread. The tyres will need to be replaced and the alignment and suspension components checked.

Another cause of noisy tyres is when the layers in the tyre casing separate and cause bulges or bumps in the tread. These can also be felt by running a gloved hand around the tread. A tyre in this condition must be replaced straight away as there is the possibility of a blowout.

So keep an eye out for uneven wear on both front and rear tyres, and if you are worried speak to your mechanic or tyre specialist.

A word about disc brake systems

Most late model cars have warning tabs on their disc brake pads. These metal tabs indicate that the brake pad is almost worn down to the metal back plate by making contact with the rotating disc rotor. This results in a shrill, but not particularly loud, squeal or whistling sound. It’s the same principle as a finger nail running down a blackboard – uncomfortable!

When this occurs, it’s time to book in to have your brakes checked and overhauled as required.

Sometimes if no action is taken to fix the problem, the metal warning tab will break off and the noise stops, giving the false impression that the problem has gone away.

The trouble is that the next noise to be heard will be the horrible grinding sound as the brakes go metal to metal. The brake job then becomes urgent and possibly more expensive and usually at an inconvenient time.

So if you hear any sounds that make you suspicious that your brakes are not 100%, give your mechanic a call to have it checked out. It will probably save you money in the long run and at least keep you and your family safe.