What’s a Wheel Bearing & How Can You Inform if Yours is Going Dangerous?

What’s a Wheel Bearing & How Can You Inform if Yours is Going Dangerous?


We needed to exchange a foul wheel bearing/hub meeting just lately, which gave us an excellent purpose to jot down this text. (Picture/OnAllCylinders)

A wheel bearing has an actual easy job: It makes positive that your wheel spins freely, with none binding or vibration. A wheel bearing’s purpose is to mitigate the results of friction, which finally improves your automotive’s potential to roll easily—all whereas decreasing put on to make sure it’s ready to take action for a very long time.

A wheel bearing is often composed of a collection of small curler bearings organized in a circle and encased in a sturdy shell. The meeting is packed in grease and sealed to forestall extreme moisture and grit ingress. Then, the entire thing slips across the car’s axle or spindle, the place it could possibly spin proper spherical, child.

Right here’s a standalone shot of a Timken wheel bearing. However in lots of instances, bearings are sometimes pressed-in to a hub meeting to get replaced as a single unit (like within the image on the prime of this text). Notice the collection of smaller curler bearings inside the primary wheel bearing. (Picture/Timken)

However given the quantity of instances it has to maintain the wheels spinning actually, actually quick (and the rain-, dust-, and salt-rich setting it usually has to work in), a wheel bearing will finally put on out. Whereas a failed wheel bearing is usually a large drawback, the excellent news is, it’ll in all probability offer you loads of warning that it’s going dangerous—you simply should know what to hear for.

Learn how to Inform if Your Wheel Bearing is Dangerous

The important thing phrase above is “hear.” Although you might be able to jack-up your car and examine the wheel for motion and play, noise will usually be your first (and finest) indicator that you just’ve bought a wheel bearing on its method out.

It’s at all times a problem to explain a noise in textual content, however a foul wheel bearing will usually begin out as a “growl,” form of like a boring, tender grinding noise. It will also be a whine, a hum, or a tender roar. In some instances, dangerous wheel bearing noise might even manifest as a clunk or squeak.

You might also begin to really feel it by means of your steering wheel or in your bottom seismograph. Once more, a wheel bearing’s job is to make sure your wheel spins easily. When it doesn’t, you’ll in all probability begin sensing disagreeable vibration and noise all through the passenger cabin.

The noise/vibration would possibly solely be noticeable at sure speeds, and it might even go away momentarily relying on chassis motion (extra on that in a sec). In any occasion, it’ll probably worsen because the bearing continues its development in direction of full failure, so it’s good that you just catch it as early as potential.

Right here’s a detailed up take a look at our outdated wheel bearing pressed into the hub meeting. Whereas it’s lined by a mud cap on the hub, ambient air, grit, and moisture can nonetheless discover a method inside. You possibly can see the curler bearings lined in grease across the bearing’s outer race. This explicit bearing endured a nasty mixture of street salt and ocean air for a number of years earlier than trying out. Bravo. (Picture/OnAllCylinders)

Keep away from a Flawed Wheel Bearing Analysis

However earlier than you level the finger at a wheel bearing, you need to make certain the noise isn’t coming from someplace else. So right here are some things to think about:

  • Ensure your tires are in good condition and correctly inflated. Worn, unbalanced, and underinflated tires can mimic the signs of a foul wheel bearing.
  • Does the noise change if you apply the brakes? Does it cease completely? Then it’s a good suggestion to take a look at your drums/discs first, earlier than going a lot deeper. In a secure space(!), experiment with some mild brake faucets, a number of laborious jabs, after which experience the brakes a bit to see if it impacts the noise you’re experiencing.
  • Does the noise change with engine pace? Remembering that engine pace and wheel pace usually change collectively, do that: Whereas coasting to a cease on a freeway off-ramp, (once more, in secure situations!) shift into impartial. If, when the engine RPM drops, there’s no change within the noise, then the noise might be linked to wheel pace, which factors to a wheel bearing drawback. (When you’re stopped after the take a look at, shift again into drive and be in your method.)

We’ve bought a extremely good article on driveline noises that goes into extra element. Test it out right here: Fast Information to Diagnosing Differential & Driveline Noises

Learn how to Observe Down a Dangerous Wheel Bearing

Now that you understand what to hear for. That you must know the place to hear for it.

Since a wheel bearing is situated at or close to the wheel, the noise will in all probability be coming from one nook of your car—supplied you’ve solely bought one dangerous bearing, in fact.

It’s normally fairly straightforward to find out if the noise is coming from the entrance or again, given the motive force’s seating place and their proximity to the entrance wheels. The laborious half is commonly figuring out whether or not the noise is coming from the left or proper (driver or passenger) facet of the car.

However excellent news there, as there’s a straightforward take a look at which will assist. Whereas it’s not 100% foolproof, should you discover the noise stops when you’re turning—and even barely veering—then an reverse facet wheel bearing is the probably perpetrator.

Right here’s an excellent illustration of the left/proper wheel bearing diagnostic course of we made utilizing our state-of-the-art rendering software program. (Picture/OnAllCylinders)

That’s as a result of turning shifts the load off the facet of the actual offending wheel. Now unloaded with much less stress, the bearing would possibly shut up for a second and be completely content material. When the car weight shift returns to regular, the bearing is again to being loaded and it’ll begin to whine once more (generally actually).

So pay particular consideration whereas turning and, at freeway speeds, should you can safely(!) rock the steering wheel barely left and proper to shift the car’s weight to every facet, it might additional allow you to diagnose the place the noise is coming from.

Once more, this isn’t a 100% correct take a look at, however it may be an enormous assist.

As alluded to earlier, we had a wheel bearing exit on a front-wheel drive car. Utilizing the processes outlined on this article, we narrowed it all the way down to the rear driver facet wheel bearing. That was excellent news for us, because the alternative job was fairly straightforward and didn’t value a complete lot both. That is the brand new hub/bearing meeting on the spindle, proper earlier than we torqued all the things down and bent the axle nut flange to maintain it in place. (Picture/OnAllCylinders)

How Lengthy Ought to A Wheel Bearing Final?

That’s a tricky query to reply with a definitive mile threshold. We hear inform of wheel bearings lasting the lifetime of the car, like 200,000 miles and up. Conversely, some vehicles (cough*outdated Subarus*cough) appear to undergo wheel bearings each few years or so.

It usually boils all the way down to each the car and the driving situations. All-wheel-drive vehicles put completely different calls for on wheel bearings than, say, entrance wheel drive vehicles. Late-model efficiency vehicles place stresses on wheel bearings that common commuter vehicles don’t. Mud-slinging off-roaders topic their wheel bearings to muck and grit {that a} street-driven automotive not often sees. Make sense?

An enormous key to wheel bearing longevity is correct set up. Earlier than placing the brand new wheel bearing again on, we cleaned all the things completely, as an errant little bit of grit or a number of rust flakes might simply shorten bearing lifespan. Right here, we’re dousing the spindle with some brake cleaner previous to some deeper scrubbing. (Picture/OnAllCylinders)

The takeaway right here is that early detection is vital. And narrowing it all the way down to the exact wheel will help prevent some money and time in diagnostic prices.

Paul is the editor of OnAllCylinders. When he isn’t writing, you may in all probability discover him fixing oil leaks in a Jeep CJ-5 or watching a 1972 Corvette overheat. An avid motorcyclist, he spends the remainder of his time synchronizing carburetors and cleansing chain lube off his left pant leg.


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September 2022