It starts with a noise. With the radio on and wind from the windows, it’s easy to ignore at first. But the more miles you drive, that subtle noise grows to a metal on metal grinding sound you can’t ignore.
You might notice other signs as well, including wobbly steering or uneven wear on your tires. These are all signs of your wheel bearing going bad, and they should all be taken seriously. Otherwise, you may end up losing the wheel while driving, which could be catastrophic.
Our advice? Know the symptoms and causes of wheel hub failure, and get it fixed as soon as possible.
Příznaky špatného ložiska kola
The symptoms of a bad wheel bearing are relatively straightforward: You’ll hear a grinding noise until you’re driving fast enough that road noise masks it (50mph and faster). The noise indicates metal-on-metal rubbing at a fast rate and comes from the faulty bearings scraping against their housing and, worse, the wheel hub around them.
If it’s the front hub bearings, turning the steering wheel may cause the noise to get worse or change in pitch.
Běžné příčiny selhání
The most common cause for wheel hub bearing failure is impact. When the tire and wheel hit an object or road defect hard, the bearings can be damaged. Likewise, broken or worn seals can allow moisture or debris into the hub, causing the bearings to deteriorate.
Other things that can cause premature bearing failure are:
- Out of balance tires/wheels
- Worn or broken suspension components
- High performance, low profile tires
Typically, these sorts of long-term wear-and-tear symptoms will also cause damage to ball joints, tie rods, struts, and other chassis/suspension components.
Two other problems that are often left undiagnosed when wheel bearings repeatedly fail are a worn bearing hub and transient current flow through the knuckle. If the bearings were grinding or otherwise making their failure known for any period of time, it’s likely that the bearing hub took some damage. When removed, it will show signs of scraping or dimpling. It may also be out of round. Any of these means the hub should be replaced.
Premature wear can also be caused by transient current flow, which is the friction created by faulty electrical grounds which allow current to build up on the moving parts of the chassis. Vehicles build up static electricity during operation and this is usually dissipated by the vehicle’s ground points. Bad ground points = bad news.
Řešení problému
In a shop, there are several methods for finding bad wheel hub bearings, including directional microphones or ultrasound. In the do-it-yourself mechanic’s garage, however, simpler methods, though more time consuming, are just as effective.
Simply listening to the wheel hubs as someone drives the vehicle can indicate which one is bad. With someone driving at 10-20 miles per hour, listen carefully to the grinding sound so you can pinpoint which wheel the noise is coming from.
If the problem wheel hub can be narrowed down to at least one axle, time will be saved. If not, the next test should be done on each wheel.
Safely lift the car and remove the tire and wheel. Then, rock the hub (via the hub itself) with hands on the top and bottom (12:00 and 6:00 oclock). If there is any give back and forth (towards or away from the car), the bearing is likely bad.
Replacing the Bearing
Luckily, bearings aren’t difficult to replace, and most modern vehicles use either bolt-in or pressed-in bearings. With the right tools, you can perform this replacement by yourself:
- Park your car on a safe, flat surface and secure the wheels you aren’t working on with wheel chocks.
- Loosen the lug nuts and use the wheel jack to lift the wheel.
- Remove the lug nuts, and take off the wheel.
- Remove the brake caliper using a socket wrench.
- Take off the dust cover, cotter pin, and castle nut. The dust cover is a small plastic or metal cap that protects the rotor’s components and can normally be removed with calipers. Beneath the dust cover are the castle nut and cotter pin, which can be removed with pliers.
- Remove the rotor. First remove the outer bearing, then the rotor itself. If it gets stuck, use a rubber mallet to jar it loose.
- Unscrew the hub bolts and take off the old hub. The wheel bearing is behind the hub.
- Disassemble the hub assembly. You’ll need to take apart the hub to get access to the bearings.
- Take off the races and clean the knuckle. This usually involves breaking the races with a hammer and chisel or a grinder. Once the races are gone, clean the knuckle inside the bearing assembly. Have rags handy – there will probably be a lot of grease!
- Install the new wheel bearings and races. Have a hammer handy to set the races in place with a few taps, then grease the new inner assembly and install it. Use plenty of grease and make sure the bearings are properly aligned and pushed in as far as they can go.
- Lastly, re-install everything in reverse order, and lower the vehicle from the jack.
Pay careful attention to the type of grease employed, the packing itself, and the alignment of the bearings in the hub.
Pressed In Bearings
With pressed-in bearings, which are more common today, the procedure is a bit more complex.
The wheel bearings reside between the steering knuckle and the hub itself, packed between the outer bearing seal and the CV joint. Removing and replacing these bearings requires a press made specifically for the job and each vehicle will be slightly different. Attempting to “pound out” the bearings with a screwdriver or other tool will result in serious damage to the vehicle’s hub and/or knuckle. The upside is that when pressed-in bearings require replacement, they are removed and replaced in one piece units that come pre-sealed and lubricated.
In all, a vehicle’s wheel hub failure is most likely caused by something other than the hub. Fixing the hub failure is relatively simple (especially with GMB’s quality bearings and hub assemblies), but diagnosing the cause of the failure may not be as easy.
For most men, learning how to drive can feel like a rite of passage. Your first car signified your transition into adulthood as cars represent some sort of personal freedom. From behind the wheel, the road ahead feels empowering.
But car ownership also requires a sense of responsibility.
As a discerning owner, or even simply as a car enthusiast, knowing how to properly diagnose car problems will prevent more serious issues down the line. And one troubleshooting issue every car owner should be able to diagnose is selhání ložiska.
As a trusted technical service provider in the region, we’ve seen how catastrophic wheel bearing failure can be. Continuing to drive with a faulty bearing can cause the wheel to completely disconnect from the axle. The inability to steer leads to unsafe driving conditions and much more complicated situations.
This can have severe consequences for you, your passengers, and other drivers on the road.
The main causes of bearing failure
Like any other car component, wheel bearings are subject to wear and tear. The lifespan of your wheel bearings is dependent on whether they’re original equipment (OE), the quality of the bearings themselves, and driving conditions.
Even so, most wheel bearings will last anywhere from 136,000 to 160,000 km (85,000 to 100,000 miles). Meaning, most wheel bearings today should last the lifetime of your vehicle.
If your wheel bearings fail before its expected lifespan, it may be due to one of the following conditions:
Špatná instalace
Wheel bearings must be mounted according to the manufacturer’s recommendations.
For most bearings, this means being mounted with a press or interference fit on the bearing’s rotating ring. Improper mounting techniques, such as applying blows to the bearing can distort bearing components.
Even a distortion as tiny as two-thousandths of an inch can cause premature failure.
This is why it’s highly recommendable to reach out to your trusted mechanic or technical service provider who will help you with the right installation practices and with the right mounting tools.
Nesprávné mazání
To be able to operate under extreme conditions, your bearings must be able to effectively reduce friction. Too much heat generated by friction can cause your bearings to deteriorate, leading to failure.
To prevent excessive friction from building up in the bearing rolling elements, a proper lubrication solution is required.
Lubricant failure is the primary cause of premature breakdown, accounting for approximately 80 percent of all bearing failures.
To ensure that bearings are always appropriately lubricated, the right type of lubricant must be used according to the temperature, nature and demand of the application. The best grease for bearings is a multipurpose grease that works with a wide range of speeds and operating temperatures and is virtually waterproof. However, different applications like heavy duty, food industry and high speed applications require a lubricant that has a different chemical composition.
Severe operating conditions
Certain driving conditions can significantly reduce bearing lifespan. Roads with potholes, for example, can damage a wheel bearing, causing small imperfections. These imperfections can cause excessive heat and friction, quickly wearing away the bearing components.
Similarly, driving on a street flooded with water can increase the risk that foreign contaminants get past the bearing seal. Contaminated grease can cause degradation, which can induce erosion, corrosion, or fatigue within the bearing.
Špatná kvalita ložisek
When it comes to bearing replacement, quality trumps quantity. While certain economy bearing manufacturers will allow you to save on upfront costs, the quality of their material can wear out quicker than OE-quality bearings.
This will result in you needing to replace your bearings more frequently and dealing with high-cost repairs and servicing.
Úpravy aut
Cosmetic or performance modifications like fitting wider rims onto your car can cause higher than normal loads, accelerating wear on your wheel bearings. To ensure your bearings continue to perform to the full length of its expected lifespan, only use OEM-approved modifications.
Symptoms of a worn wheel bearing
Now that we have a clear overview of the common causes of bearing failure, let’s examine the symptoms that indicate a worn-out wheel bearing.
1. hluk
The first signal that you may need to replace your wheel bearings is a loud grinding or roaring sound coming from one of your wheels. A grinding noise will indicate that mechanical damage has already occurred in the wheel assembly.
Other noises you might hear that could indicate worn wheel bearings include rumbling, growling, clicking, snapping, and popping.
Because your wheel bearings are connected to other components in the wheel assembly, don’t immediately assume that a noise heard from the wheel area is a bearing problem. Bring your vehicle to an automotive professional to have it inspected.
2. Steering wheel vibrations
While vibration or shaking in the steering wheel may be an indicator of bearing failure, other issues such as out-of-balance tires can also be a contributing factor.
An easy way to differentiate between a tire balance problem and bearing failure will be to notice the speed in which vibration occurs. Steering wheel vibration due to misalignment or unbalanced tires typically becomes noticeable at higher speeds.
Vibrations due to wheel bearing failure can be noticed at much slower speeds. What’s more, steering wheel vibrations will also be noticeable during turning. Aside from vibrations, noise from the tire area will also be present.
3. Excessive play in the wheels
Excessive wobble or play can also point to worn bearings. However, this symptom is harder to diagnose.
To confirm what that additional play in the tires means, you’ll need to jack up the vehicle. Once your car is lifted off the ground, grab the tire at 6 o’clock and 12 o’clock. Attempt to rock it back and forth. The “wiggle” room you feel when rocking your tire is play.
If your tire feels loose when you rock it back and forth, your wheel bearings may be worn. A mechanic can confirm your diagnosis.
4. Nerovnoměrné opotřebení pneumatik
There are many reasons that can lead to your tires experiencing abnormal wear — from improper alignment and over- or under-inflation to worn suspension components and loose wheel bearings. To diagnose if your tire wear is bearing-related, examine its wear pattern.
If it displays cupping, scalloping, feathering, or diagonal wear, the main culprit could very well be a worn bearing.
5. Abnormal pulling
If your car tends to slightly pull to one side, particularly during braking, you may have a bearing problem. But brake pull can be easily misdiagnosed as it can be caused by several issues such as warped rotors, worn suspension components, or a defective caliper.
To confirm the source of the fault, have an automotive technician inspect your vehicle.
Knowing what symptoms to look for can help you take corrective action before more damage can occur.
If you detect any of these warning signs, consider having a certified mechanic inspect your vehicle. Not only can they appropriately troubleshoot the problem, but they also have the skills and experience to properly refit your bearings should they be the culprit.
AUTOR BIO
Hassanein Alwan is the Managing Director of Mineral Circles Bearings with more than 10 years’ experience in the bearing industry’s technical support division, sales and marketing, plus strategic business development consultancy.
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