Wheel Hub Buyer's Guide
- The wheel hub serves as the connection point between the wheel and the rest of the vehicle.
- Other terms for the wheel hub include wheel hub bearing, wheel hub assembly, wheel hub unit, hub assembly, and hub and bearing assembly.
- The wheel hub assembly keeps the wheel attached and rolling freely and supports the ABS and TCS.
- The hub and the bearing are the main components of a wheel hub. 4WD vehicles use two types of locking hub: manual locking and automatic locking.
- The brake shield, the rotor disc, brake calipers, anti-lock braking system (ABS) harness cable, and wheels are attached to the wheel hub assembly.
- The symptoms of a bad wheel bearing include: grinding and rubbing noises; humming noises; switched on ABS light; looseness and vibrations in the steering wheel; wheel vibration and wobbling; uneven rotor or tire wear; and a play in the wheel when you shake it with two hands.
- Driving with a bad wheel bearing hub increases the risk of accidents.
- Experts recommend replacing it every 85,000 to 100,000 miles or when you see symptoms of a bad wheel hub assembly.
- Consider bolt patterns, hub types, condition, and fit when buying a wheel hub replacement.
- Wheel hubs cost around $13 to $190, including on items of varying part inclusions, quantity, fitting locations, and type.
- Factors that affect the cost of wheel hub repair include your vehicle's size, type, make, model, and ABS.
- Installing a new wheel hub on your own is easy if you have the right tools and know-how.
Wheels transport a vehicle over a ground surface. Simultaneously, the steering system controls the wheels and the direction that the car travels in. These two different powertrain components can work together smoothly and safely thanks to the efforts of the wheel hub assembly that attaches them.
What is a wheel hub?
The wheel hub serves as the connection point between the wheel and the rest of the vehicle. It sits between the brake drums and the drive axle, and the wheel itself bolts onto the pre-assembled part.
It is a mounting assembly that holds your wheels with studs and bolts, as well as the bearings, brake rotor, anti-lock braking system (ABS), and brake calipers. Due to its function, the wheel hub is considered to be one of the most essential components inside your car.
Other terms for the wheel hub include wheel hub bearing, wheel hub assembly, wheel hub unit, hub assembly, and hub and bearing assembly. It forms a mainstay part of most cars, trucks, and passenger vehicles.
What does the wheel hub assembly do?
The wheel hub fulfills roles whose importance proves disproportionate to its size when compared to the wheel or the steering system. If the assembly goes out of whack, the wheel attached to it will behave erratically and even dangerously, affecting the entire car.
Keeps the wheel attached and rolling freely
Perhaps the wheel hub’s most apparent and important role is making sure that a wheel rolls properly and smoothly. Its bearings reduce the friction experienced by the spinning wheel and lessen the noise made by the wheel. The vehicle becomes easier and more pleasant to operate.
Supports the anti-lock braking system (ABS) and the traction control system (TCS)
Aside from wheel bearings, a wheel hub assembly contains sensors that keep track of the speed at which the wheel spins. It sends the data to the vehicle’s ABS and TCS.
As its full name implies, the ABS prevents the car from skidding uncontrollably. When the wheels threaten to lock up, the system pops the brakes just long enough to let the wheel’s surface continue to grip the road surface.
Likewise, the TCS also gets data from the sensors in the wheel hubs. The two systems team up with the driver to keep control of the vehicle while driving on slippery roads.
What are the main components of a wheel hub?
A wheel hub assembly is composed of multiple parts including hardware like washers, nuts, retainers, and a cotter pin. However, its main components are the hub itself and the wheel bearing.
The hub is where you mount your wheel on. It’s the round metal piece that has four or more studs protruding outward. Four-wheel drive (4WD) vehicles use a locking hub and there are two types known as manual and automatic locking hubs.
Manual locking hub
This is a type of 4WD hub that can be disconnected from the 4WD system manually. This means you have to step out of your vehicle and physically turn the knob on the hub with your hand. Manual locking hubs are believed to be more durable than automatic ones due to its simple mechanism.
Automatic locking hub
This type of locking hub is controlled by a computer and can be triggered with a press of a button. Some 4x4 vehicles can lock the hubs on the fly, while some demands a quick stop to activate the system. Automatic locking hubs, when compared to manual, are far more convenient because you won’t need to step out of the vehicle to disconnect it from the system.
The bearing is a set of steel spheres bonded inside a metal ring known as a race. It helps the wheels spin freely by eliminating friction and is considered to be the primary link between the static and moving parts of the vehicle. The wheel bearing is the inner component of a wheel hub assembly as it is directly facing the metal axle shaft.
What are the car parts attached to a wheel hub assembly?
A wheel hub assembly is a hollow piece of round metal with studs sticking out on the other side. It is where you install or attach the brake shield (also known as backing plate), the rotor disc, brake calipers, anti-lock braking system (ABS) harness cable, and the wheel itself.
The number of studs protruding out from the hub depends on the make, model, and what vehicle type it is for. There are hubs with four studs, while others have five or six. These studs are where the lug nuts are installed to hold the wheel firmly on the hub assembly. The assembly is then inserted to the axle and bolted onto the steering knuckle.
What are driven and non-driven wheel hubs?
Driven and non-driven wheel hubs often look the same, although driven wheel hubs need to support the drive shaft. Drive shafts are what make your wheel spin through the use of splines and grooves. Splines are ridges at the end of a metal rod that fits snuggly into the grooves of the hub.
Driven wheel hubs are found either in front or at the rear, depending on the drivetrain layout of your car. On the other hand, the hub turns outside a stationary, central, solid stub axle in non-driven wheel bearings.
Front driven hubs are usually more intricate because they need to do two jobs, which are to spin and swivel. Rear driven hubs don’t need to swivel as rear wheels don’t need to turn.
Bad wheel hub bearing symptoms
When a wheel hub does its job right, its attached wheel rolls quietly and quickly. But like any other car part, it will wear out over time and with use. Since the vehicle always uses its wheels, the hubs never get a break for long.
Common scenarios that can batter or wear out wheel hub assemblies include driving over potholes, hitting fairly large animals like bear cubs and deer on the highway, and collisions with other vehicles.
You should have your wheel hubs checked as soon as possible if you experience the following symptoms:
Grinding and rubbing noises
While operating your vehicle, you may suddenly get an earful of sharp noises made by two metal surfaces as they scrape together. Typically, damaged wheel hubs and bearings put out an audible grinding noise at speeds higher than 35 mph. This could be due to the bearings not working properly or that some hardware components are already in bad shape to begin with.
If your bearings are not in a smooth-sail condition, your wheels won’t spin efficiently. You could tell it by observing your car’s coasting capability. If it slows down quicker than how it usually does, it could be that your bearings are preventing your wheel from spinning freely.
A faulty wheel hub assembly doesn’t just grind metal together. It can also produce a sound that resembles humming. Treat the humming sound with the same care as grinding sounds and bring your vehicle to the nearest auto shop, preferably by tow truck.
ABS light switches on
The ABS monitors the status of the wheel through electronic sensors. If the system diagnoses anything amiss, it will activate the ABS indicator light on the vehicle’s dashboard.
Given the wheel hub belongs to the wheel assembly, the ABS keeps track of its performance. When the wheel finds it harder to spin because of a bad or ailing hub and bearing assembly, the diagnostic system switches on the ABS light.
Looseness and vibrations in the steering wheel
When a car with a worn-out wheel bearing in its hub assembly builds up speed, it may cause vibrations in its steering wheel. The faster the vehicle goes, the worse the vibration becomes, and it can make the steering wheel feel loose.
Wheel vibration and wobbling
Audible noises aren’t the only signs you need to observe. If you feel some jerkiness or vibrations in the steering wheel when you are driving, chances are there are issues in your hub assembly. Two of the common reasons why this happens are the loss of clamp and a badly worn-out bearing. Also, you’ll observe an abnormal pull to the side when braking due to a possible defective brake rotor – although it could also mean that your calipers aren’t functioning properly.
Uneven rotor/tire wear
You’ll also able to tell your that hubs aren’t in good shape when you start changing rotor discs individually. Why, you ask? It’s because rotor discs often worn out together. Abnormal wear on your rotors is an indication that something’s wrong with one of your wheel hubs. Unusual tire wear, on the other hand, points to issues in one of the hubs’ bearings.
A play in the wheel when you shake it with two hands
One simple way of checking if you have faulty wheel hubs is by holding your wheel with two hands on a 9:15 or 6:00 clock position. If your wheel hub is completely fine, you shouldn’t be able to feel even a slight looseness, wiggle, or what mechanics call a play when you try pushing and pulling it alternately with your hands. If you tighten the lug nuts and still get a play, you need to replace your wheel hubs as soon as possible.
Why you shouldn’t drive with a bad wheel hub
Wheel hubs keep the vehicle stable and controllable. As they and their bearings wear out, the wheel attached to them starts experiencing more friction during its spinning, which affects its performance and the vehicle’s controllability.
Since the hub assembly is the sole connector of the wheel and the vehicle, serious accidents may occur if one of the four wheel hubs fails. A failure in the hub assembly could cause sudden changes in handling and braking, as well as abrupt stoppage in wheel spin. Replacing the damaged hub can save you, everyone around you, and your beloved car from any fatal accidents caused by loss of control.
Another risk of driving with a failing wheel hub is tire wear. If one or two of your tires wear out quicker than the others, there are high chances of tire explosion that could be extremely dangerous at high speeds. There are tons of advantages of replacing your failing wheel hubs, including improved their fuel economy and smoother driving experience. On top of everything, there is no better feeling than driving with a peace of mind.
If you hear grinding or humming noises from your wheels or notice that the ABS light is switched on, bring your vehicle to a reliable auto repair shop as soon as possible.
When should you replace your wheel hub assembly?
Experts even recommend its replacement every 85,000 to 100,000 miles. It's always good to follow this kind of sound recommendations to avoid the hassles of travelling. If you notice any of the symptoms of a bad wheel assembly before then, have your vehicle checked by a professional mechanic immediately.
Things to consider when choosing a wheel hub replacement
The wheel hub comes in different dimensions and types, each offering its own set of advantages. So if you're trying to get your hands on the right wheel hub for your vehicle, here's a guide to help you out.
When checking different wheel hub models, always take a look at the number of bolt holes. Typically, there are four, five, six, or eight bolt holes that are equidistant from each other and arranged in a circular pattern around the middle of the hub. You must measure an even bolt pattern by checking the distance from the top center bolt and down to the bottom center bolt. Meanwhile, measure an uneven bolt pattern in straight line from the top center bolt to the bolt that's farthest away.
This kind of hub functions on both the one- and two-piece axle forms. The widths of the axle extend from 100mm for classic hubs to 135mm for the mountain low-flange rear hubs. The diameter of the flange on both the passenger and driver side range from 40-53mm. On classic hubs with additional fun-bolt back end axle options on classic mountain rear hubs, a frame attachment design included quick-release preferences.
Universal Disc Hubs
This design is made for rear, front, and single speed hubs and fit on one-and two-piece axles. The width of the axles has a larger range that's from 100-160mm. For both the passenger and driver side for universal disc hubs, it has a flange diameter of 53mm. This type of hub weighs 150 to 457g, with the universal disc front models having the lightest weight compared to the universal disc singe-speed rear models that are the heaviest.
Not all wheel hubs come with 100% brand-new components. Some of them are remanufactured. Some parts have been restored or repaired, and these are used in the assembly. Remanufactured options come at a cheaper price. Though some may doubt their quality, some manufacturers test and assess the remanufactured units to ensure proper function and good quality. If you don’t want to settle for less and want every component in the assembly to be brand new, you can always search for items from top brands and trusted sellers. Check the product specs to be sure that what you’ll get is completely new.
Wheel hub assemblies are available as a direct fit or as universal items. A universal wheel hub assembly can fit a wide range of vehicle models. Before you buy, be sure that the part matches the specs of your vehicle and meets the wheel requirements. Look for an assembly that’s specifically manufactured to precise OE specifications so you can be sure that it will fit onto the wheel bearings and won’t fall off easily.
Aside from considering the wheel hub specifications, you also have to check the size of the hub. Here are tips to keep in mind.
- Check the sidewall of the tire and look for a series of letters, numbers, and the manufacturer's name.
- Find the last set of numbers that begins with R, which stands for radial.
- The two numbers after the R correspond to the measurement in inches of the wheel hub size. 14 and 18 mean that the wheels are standard on the automobile. If the numbers have slightly rubbed off, you can always use a magnifying glass so that you can read them properly.
How much does a wheel hub replacement cost?
Prices for wheel hub assemblies are specific to the type, fitting location, and quantities it is being sold. For the type, there are driven and non-driven; fitting locations are front driver or passenger and rear driver or passenger sides; while quantities include individual, kit, or set parts. These categories branch out to even more subcategories, such as hubs that don’t come with bearings or those without ABS harness cables.
You can save money by obtaining the replacement wheel hub from a trusted company like CarParts.com. Driven and non-driven hub assemblies that are sold individually (regardless of fitting location and part inclusions) are priced around $13 to $890, while kits have price tags ranging around the $50 to $890 budget mark.
By entering the year, make, and model of your vehicle in the filter tab, you can quickly track down a wheel hub guaranteed to fit your pickup or car.
What are the factors that affect the cost of wheel hub repair?
Many factors determine the cost of a repair job involving a bad or failing wheel hub. Your vehicle’s type, make, model, and features can make the task easier or harder.
In general, the larger the vehicle, the heavier and more expensive the wheel hub. So, installing new hubs on a pickup will cost more and require more effort than in a passenger car.
The presence of an anti-lock braking system drives the cost even higher. Auto repair technicians need to take extra steps and care to avoid disturbing the ABS system while replacing the wheel hub.
Fortunately, it is possible to service worn-out wheel bearings without having to replace the entire wheel hub. A trained technician can tell if the fault lies with the bearings or the hub assembly.
How to install a wheel hub assembly
Smooth steering will be very impossible for your four-wheeled buddy if your wheel hub assemblies are in bad shape. Because they are responsible for connecting the wheels to the chassis of your vehicle, all your wheel hub assemblies must be properly maintained.
If any of the four hub assemblies produces unusual noises like growling, squealing, or grinding, it means that there is already something wrong. If you think a wheel hub assembly replacement is needed, follow these instructions for the installation. The duration of the process depends on how many wheel hub assemblies you need to replace. But usually, one wheel hub assembly takes about an hour to finish.
Needed tools and materials
- New wheel hub assembly
- Floor jack
- Jack stands
- Wheel chock
- Tire iron
- Socket and ratchet set
- Bungee cord
- Breaker bar
- Sand paper
Step 1: Preparing the vehicle
Park your vehicle on a spacious and level ground and apply the parking brake. If you are installing the new hub assembly on the front wheel, put the chock at the back wheel. Loosen the lug nuts about one-quarter of a turn using the tire iron. Do not remove them completely. Lift the vehicle using the floor jack and set up the jack stands underneath.
Step 2: Removing the tire and the brake assembly
Once the car is lifted and properly placed on the jack stands, remove the lug nuts and pull the tire away from the wheel assembly. Look for the brake caliper bolts and take them off using the ratchet and socket. With your screwdriver, carefully remove the caliper and support it with the bungee cord. If necessary, you can also remove the brake pads. After that, take the brake rotors off the hub assembly. If your vehicle is equipped with an ABS wiring harness, unplug them from the assembly as well.
Step 3: Taking out the old wheel hub assembly
Use the breaker bar and the socket to loosen and remove the spindle nut and the washer. Look for the wheel hub assembly bolts and remove them using the ratchet and socket. Move the drive shaft and the spindle to provide easier access to the old hub assembly. After that, carefully pull the old wheel hub assembly away from the spindle. Use the sand paper to remove rust or any sign of corrosion before installing the replacement hub assembly.
Step 4: Installing the new wheel hub assembly
Position the new wheel hub assembly. Put the new backing plate onto the knuckle and reposition the drive shaft and the spindle. Make sure they are at the center of the hub bearing. Reattach the bolts of the wheel hub assembly and securely tighten them using the breaker bar and the socket. Put the new washer and spindle in place. Re-install the brake assembly and re-connect the ABS wiring harness. After that, remount the wheel and tighten all the lug nuts in place.
Step 5: Evaluating the new wheel hub assembly
Remove the jack stands and lower your vehicle. If you are going to replace all the wheel hub assemblies in your vehicle, just repeat the entire process on each hub assembly. Remove the wheel chock. Test drive your vehicle to check if the annoying noise is gone and if everything is working properly.
Tips and warnings
- If you are having any difficulty in removing the brake rotors and/or the old wheel hub assembly, you can use a rubber mallet to tap them off the assembly and/or the spindle.
- For some vehicles, you might need to use a slide hammer before you can access and remove the old wheel hub assembly.
- In putting back the caliper, you can use a C-clamp to put pressure on it so that it will be securely attached to the rotor.