How to tell which wheel bearing is bad front or back?

The wheel bearings in the car have the task to let the wheel roll on the axle.

Defects in the wheel bearing can occur with increasing age and stress on the car.

Especially when regularly driving through tight curves and on curbs, wheel bearings are highly stressed and wear occurs. Often the driver of the vehicle does not immediately notice the defect of the wheel bearing. In the worst case, this can result in expensive consequential damage.

Function and tasks

Wheel bearings are parts of the chassis. As the name suggests, they are the bearings to which the wheels of the vehicle are attached. Their task is to guide the wheels and absorb radial or axial forces. Or simply put, they ensure that the wheels run smoothly.

They are actually subjected to constant stress. They are subjected to extreme forces, especially on winding roads. Furthermore, they are also among the wear parts. That means they have to be replaced in due course. But how do you recognize in time that your wheel bearings need to be replaced? And how can you extend their service life?

Protecting wheel bearings

Wheel bearings are designed to withstand high loads and environmental influences. But reckless driving can cause them to break down more quickly. Their biggest enemies are hard knocks. That’s why you should avoid potholes as much as possible.

Bumping against the curb is also poison for the bearing. Furthermore, extreme cornering has a negative effect on the service life of the wheel bearings. Sooner or later they have to be replaced anyway. But by driving with foresight, the change will be necessary later rather than sooner.

How can I recognize a defective wheel bearing?

At the beginning of a defect, not much happens yet. It is also not visible from the outside, as the wheel bearing is covered by the wheel itself. The sign of increased fuel consumption is also not always noticeable. However, damage to the wheel bearing becomes noticeable after some time through noises.

While driving, broken wheel bearings cause unnatural and creaking noises.

Noise is the first sign that the wheel bearing is broken. Think of the dull sound as similar to heavy marbles rolling back and forth in a thick-walled pot. The noise can be localized fairly accurately. If the noise occurs only when cornering, the damage is still “young.” If it rolls and grinds even when going straight, you should not continue driving – at most until you reach a workshop.

Other symptoms of a broken wheel bearing:

• Skewing when braking.
• A changed steering feel.

The symptoms mentioned here are quite clear. It’s bad if your vehicle comes to a stop sooner when approaching a traffic light than it did before. Such symptoms, occurring individually or together, require a prompt appointment at a specialist workshop.

How to tell which wheel bearing is bad

In order to determine which wheel bearing is broken, you must first locate the side from which a suspicious noise is coming. There are two situations for this: Checking the wheel bearing while driving or checking the wheel bearing when the car is jacked up.

Checking defective wheel bearings while driving

If the described sound is heard when driving in a right-hand bend, the left wheel bearing is often defective.

The right side is checked in the same way as the left side. If the sound is heard when driving through a left-hand bend, the right-hand wheel bearing is often defective. If the defect is advanced, driving through an empty tunnel can also help. With the windows down, the reverberation thrown back by the tunnel walls can be helpful in locating the affected side of the defective wheel bearing. However, this is not sufficient for an accurate diagnosis.

Jack up the car to check the wheel bearings

Another method of identifying the defect is to jack up the vehicle with a jack. With a free-floating wheel, the so-called wheel bearing play can be checked. To do this, grasp the wheel firmly with both hands and test it by moving it in opposite directions. A defective wheel bearing or excessive wheel bearing play feels as if the rim is not bolted tightly enough to the wheel hub.

Testing wheel bearings reliably in the workshop

When testing the wheel bearing itself, it is not always possible to reliably say whether the wheel bearing is in order or whether it is damaged. However, if the noise does not occur with any of the methods described here, a broken wheel bearing is rather unlikely. If the noise you noticed at the beginning reappears at another time, it is probably a different problem. Only a check in the workshop can give a reliable answer here.

When to replace a wheel bearing on the car

There are two basic rules that should be followed. First, if the aforementioned tests reveal any abnormalities that indicate a damaged bearing, you should arrange for a replacement as soon as possible.

Secondly, the bearings should be replaced after a certain mileage to be on the safe side.

Depending on the manufacturer, should last around 100,000 miles when maintained properly.

In both cases, it is advisable to replace all-wheel bearings on the vehicle at once.