Symptoms of truck wheel bearing damage
Symptoms of truck wheel bearing damage

What is a wheel bearing

Bearings have an important impact on the performance of the whole truck. In terms of reliability, if they are damaged, they can affect the entire truck. In terms of safety, the location of some bearings is very important, such as wheel bearings, which are one of the key components of a truck. A wheel bearing consists of a set of steel balls that are held in a metal ring, called a raceway. In the centre of your wheel there is a hollow piece of metal called the hub. The wheel bearing fits snugly into this hub and rides on a metal axle to help reduce friction as the wheel spins.

This differs from engine bearings in that wheel bearings do not have a constant source of lubrication, which means they need to be tight enough to protect against water and road dust. Its primary role is to carry the weight and provide precise guidance for the rotation of the hub, carrying both axial and radial loads, and is an essential part of the truck’s load and rotation. In the event of a failure, the safety of the entire vehicle can be affected. The mounting, oiling and sealing of the bearings as well as the adjustment of the play are all carried out on the production line.

What is the service life of a wheel bearing? 

Most wheel bearings will last for approximately 85,000 to 100,000 miles from installation to replacement. Some trucks even have a longer wheel bearing life because they are replaced more frequently. Although wheel bearings are designed to extend the overall life of the truck to a certain extent, sealed bearings can break, they can break and wear out. And it all depends on the quality of your wheel bearings and the conditions in which you normally drive. As your wheel bearings sit on your wheels, they need to be able to withstand potholes, speed bumps, rain, dust and other driving conditions, all of which can reduce their lifespan and the consequences can be severe, often resulting in damage to axles, steering knuckles, wheels and even tyres, during which time steering can become problematic. Fortunately, there are usually unusual sounds that occur long before a failure with serious consequences occurs.

Signs of wheel bearing damage and inspection methods

1. In most cases, the initial stages of a bearing problem are accompanied by a low rumbling sound which varies with the speed of the truck and the axial (left and right) load. The initial noise from a damaged wheel bearing is not always easy to distinguish from that of a tire, especially if the tire tread is traumatized or the tire is badly worn.

There is a trick to distinguish between bearing noise and tire noise during a road test: drive the truck at medium speed and turn the steering wheel slightly from side to side.

But which bearing is the problem? As many trucks have double roller sealed bearings, it is not easy to determine which bearing is at fault. A good rule of thumb is that the wheel bearing opposite the one that sounds noisy during the road test is often the one with the problem.

A good way to determine which bearing is making the noise is to use a mechanical stethoscope. Lift the truck up, taking care to have good ventilation. Have an assistant start the truck to spin the wheels, at which point you can place the stethoscope’s probe on the steering knuckle or bearing housing. Check the bearings on both sides so that you can determine which side is rattling.

Remember: if one side of the wheel bearing shows signs of wear, the other side has also covered approximately the same mileage. The logical thing to do is to replace the bearings on both sides unless the damage to the bearings is caused by an obvious external cause.

Of course, for non-driven wheels, some variation is required when using this method. In this case, have an assistant turn the wheel as quickly as possible while you listen with a stethoscope. In order to get the wheel turning as quickly as possible, it may sometimes be necessary to increase the brake clearance.

Unfortunately, in most cases, especially in the early stages of bearing damage, it is difficult to determine bearing failure with a stethoscope without applying sufficient radial load to the faulty wheel. It may be difficult to determine a bearing failure without a dynamometer until the bearing has been further damaged.

  1. Sometimes wheel bearings can wear out with a large gap but without creating additional noise, a problem that is not difficult to detect during routine checks of the steering and suspension system. Lift the truck up, grab it at 6 o’clock and 12 o’clock and wiggle the tires firmly. If there is any wobble, repeat the above action and call an assistant to observe and feel. If there is no clearance, check the adjustment clearance of the bearings. If the bearing clearance is non-adjustable but there is a gap present, in this case, the bearing needs to be replaced.

3. In addition to unusual sounds to identify damage to the wheel bearings, there are several other ways to determine if there is a fault.

3.1 Loose steering wheel

When a wheel bearing is bad, you may feel some looseness in the steering wheel. This is because when a bearing wears out it becomes loose within the hub and spindle, so if this happens you will need to focus on the wheel bearing area.

3.2 Lateral lean to one side when braking

Corroded or pitted wheel bearings transmit vibrations through the steering when the truck is applying brake pressure. This can also cause the truck to pull to the side of the faulty wheel bearing.

3.3 Wheel vibration and wobble

When the wheels vibrate or wobble, the bearings are very loose. This is because the bearing has lost its clamp hold and there may also be some serious mechanical damage, at which point it is necessary to stop and have the wheel bearing repaired and replaced.

Can I drive with a bad wheel bearing?

It is not recommended to drive with a non-functioning wheel bearing. In mild cases, it can affect comfort, tire noise becomes loud and the truck runs off course; In severe cases, it can cause suspension damage and make the steering system malfunction and cause a traffic accident, which is not only very dangerous for you, but you can also end up injuring or killing other drivers on the road.

If you neglect a bad wheel bearing, driving at high speeds for long periods of time can lead to a dramatic increase in heat generation, causing unnecessary wear and stress on other components, such as the wheel hub and transmission. If you don’t fix or replace a damaged wheel bearing as soon as possible, you may have to spend more money on a truck repair service, which will be more expensive than the original problem.

By Bethann

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