Wheel bearings are small but extremely important components of a vehicle’s suspension. Bearings allow the wheel to rotate smoothly around the hub. Bearings should be inspected and checked regularly and replaced if need be, to avoid a potentially dangerous situation.
A wheel bearing consists of a circular row of ball bearings enclosed in a metal housing. Bearings are protected from dirt and debris by oil seals. There are two primary types of wheel bearings, sealed bearings that cannot be disassembled, and adjustable bearings, the latter of which are typically found on older vehicles. The wheel bearings ride on a smooth metal race, which is pressed into the vehicle's hub, and allow the wheel to rotate smoothly.
Wheel bearings can fail if dirt, oil and debris are allowed to get past the seal. Over time the bearings get scored and eventually will fail. Another cause of wheel bearings wearing out is wheels being offset incorrectly and not located the proper distance from the bearings, which creates additional stress and wear.
A bad or worn bearing can exhibit a number of different symptoms, including rubbing or grinding sounds from the suspension when the vehicle is being driven. Depending on what side of the vehicle the worn bearing is on, the noise may get worse when the car is driven around turns. Symptoms can also include tires that wander and loose-feeling steering.
If a wheel bearing fails completely, it can create a very dangerous situation. The wheel can start to flop around in the wheel arch, damaging the brakes and the hub and potentially even coming off of the car.
To determine if your bearings are bad, use a floor jack to lift the vehicle, and place it securely on jack stands. Place your hands at nine and three o’clock on the tire and attempt to rock it back and forth. If the wheel and tire move at all, you could have a bad wheel bearing. It is also important to periodically inspect the bearings, the bearing races and the hub. The bearing and races should be smooth and free of scratches and be lubricated with plenty of wheel bearing grease.
Worn wheel bearings should be replaced immediately. If you suspect the bearings are excessively worn, the vehicle should not be driven. Depending on the vehicle, wheel bearing replacement can range from $100 to several hundred dollars or more.
