You might not see them in the usual course of driving your car, but wheel bearings are what allow your vehicle to glide gently down the road. Without wheel bearings, friction would be nearly impossible to overcome, and your car wouldn't budge. That, or we'd be relying on copious amounts of lubricant.
What Wheel Bearings Do
Between the wheels and the axles/hubs, wheel bearings are there, ensuring that the wheels turn. The wheel bearings contain either steel ball bearings or tapered bearings that give a friction-free surface for smooth spinning.
How Long Wheel Bearings Last
The lifespan of a wheel bearing varies dramatically depending on the era a car was built, what type of vehicle it is (small sports car, truck, off-roader, etc.), and the quality of the bearing.
These days wheel bearings should last anywhere from 80,000 to 100,000 miles. If you're driving an older car, say from the '70s or '80s, your wheel bearings could have a lifespan as limited as 30,000 miles.
It's possible to upgrade some older vehicles with modern bearings to avoid that bit of maintenance, but not always. Sometimes it's the inherent design of the vehicle that prevents modern bearings from being installed. However, some DIYers are willing to make the modifications necessary to make newer bearings fit older cars.
What Causes Wheel Bearings to Fail?
Wheel bearings can fail because of:
When the wheels aren't set straight, perhaps due to poor suspension adjustment or damage from an accident, they can put undue stress on the wheel bearings and cause them to fail early.
Never discount human error in premature bearing failure. The techs installing the bearings may have used the wrong tools or reused parts, causing the bearings to sit at an odd angle.
The Bearing Is Cheap
Bearings with poor construction or quality control can fail early. They may not have been treated for different conditions and rust, or they may not be able to handle the strain that an OEM or high-quality replacement can.
If you're driving through lots of mud, dirt, salt, and other abrasive or contaminated materials, they can make their way into the bearings and start to wear them away.
What Are the Symptoms of Wheel Bearing Failure?
You'll want to watch out for the following:
If you suspect a wheel bearing is going bad after you're done with a drive, touch the center of the surface of the wheel. If it feels hotter than the other wheels, it means there's more friction occurring in that particular one, which can be due to the bearing not moving smoothly.
If you hear a grinding or whirring noise coming from one corner of the car, it's probably a bearing going bad.
If you feel like the steering wheel isn't as connected to the road as it should be, that's probably because it's not. As a wheel bearing wears out, it introduces play where there shouldn't be any.
Fixing Wheel Bearings
Repair is where you'll probably need the services of a professional. Removing and replacing wheel bearings takes specialized tools that the average person doesn't have in their garage.
Have the bearings replaced, but look for other underlying causes in case the wear is premature. If you don't, you'll be replacing that bearing sooner than later.
Bearings provide a smooth ride by allowing your wheels to turn freely. They're an important component that shouldn't be overlooked.