One of the highly overlooked yet highly critical components of the drive-axle and steering assembly are actually the wheel bearings. Every wheel on your vehicle is attached to a hub and inside this hub is a set of lubricated wheel bearings that permit your tires and wheels to spin freely without building up too much heat. They are configured to last a very long time, but eventually, they will lose their lubricity, wear out, and need to be changed. They can even become loose from wear from inside the wheel hub assembly. If they break entirely, it can cause a wheel/tire combination to fall off the vehicle while at speed, resulting to a very unsafe driving situation.
Prior to 1997, most vehicle, trucks, and SUVs manufactured and sold in the US had an inner and outer bearing on each wheel which was recommended to be serviced every 30,000 miles. As technology improved, newer cars were equipped with a “maintenance free” single wheel bearing designed to extend the life of wheel bearings without having to be serviced. From time to time, these “indestructible” wheel bearings will wear out and require replacement before they break.
Here are 4 warning symptoms that are rather simple to recognize and show a worn-out wheel bearing that needs to be replaced.
1. Abnormal Tire Wear
There are many individual mechanical issues that can lead to abnormal tire wear including under or over-inflated tires, CV joints, struts and shocks, and a misaligned suspension system. However, one of the most regular sources of uneven tire wear is worn out wheel bearings. It’s very hard for wheel bearings to wear evenly. As such, if the left tire is showing more wear, it might show a problem with the left wheel bearing. Still, wheel bearings need to be changed together; if there is a problem with one side, you need to change the other wheel bearing on the same axle. If you or a tire technician notice one side of your vehicle’s tires wearing out quicker than the other, contact a certified mechanic to road test and diagnose the cause of this tire wear. In many situations, it can be something different or minor, but you don’t want to risk having a wheel bearing break.
2. Roaring or Grinding Noise from the Tire Area
It’s very hard to detect a failing wheel bearing since it happens infrequently and when they do wear out, it can occur fast. That being said, one warning sign of a worn out wheel bearing is a loud roaring or grinding sound coming from the tire area of your vehicle. This is caused by excess heat that has built up inside the wheel bearing and lost most of its lubricity. Basically, it’s a metal-to-metal sound you’re hearing. It’s equally common that you’ll hear this from one specific wheel and not both sides at the same time, showing uneven wear. Like the above issue, if you notice this warning sign, contact a certified mechanic as soon as possible so they can diagnose the source of this sound and fix it before it gets a safety issue.
You might equally hear snapping, popping or clicking sounds that may show a bad wheel bearing. Though often an indicator of a worn CV joint, a snapping or clicking sound may be caused by inadequate bearing clamping. It may be particularly noticeable when taking making sharp turns.
3. Steering Wheel Vibration
Another common sign with other mechanical problems in the drive and steering assembly, a vibration in the steering wheel can be caused by worn out wheel bearings. Unlike a tire balance issue that typically shows up at higher speeds, a vibration in the steering wheel due to a bad bearing will be observed at slower speeds and progressively get worse as the vehicle accelerates.
4. Additional Play in the Wheels
This is not very common for normal vehicle owners to diagnose. However, if you have the tire jacked up or the car is on a hydraulic lift, you can check this one out yourself. Grab the wheel on opposite sides and attempt to rock it back and forth. If the wheel bearings are good, the wheel won’t “wobble.” However, if the tire/wheel assembly moves back and forth, it is very likely due to worn out wheel bearings that need to be changed as soon as possible.
Additionally, if you observe the vehicle has a hard time rolling while the clutch is depressed or the car is in neutral gear, it can be caused by wheel bearings that are worn out, creating friction, and could be failing.
Anytime you observe any of the above symptoms of a worn out or failing wheel bearing, meet a dependable certified mechanic who will road test, diagnose and change the wheel bearings where necessary.