Locking Hub Buyer's Guide
- Locking hubs, known by some as free-wheeling hubs, are designed to lock and free the front wheels from the front axle when switching between 2WD and 4WD.
- Manual and automatic are two types of locking hubs.
- Choosing between manual and automatic locking hubs is more of a preference thing, as it boils down to convenience and ease of maintenance.
- Locking hubs require regular inspection and are not serviceable once they get damaged. There are conversion kits that let you swap from manual to automatic locking hubs and vice versa.
- Difficulty engaging or disengaging properly and grinding noises are the most common symptoms of bad locking hubs.
- OE replacement locking hubs on CarParts.com cost $30 to $2,000, and are sold individually, in pairs, or as part of a kit.
Off-roading is a demanding driving activity and is one of the toughest motorsports-related hobbies even up to this day. This is why there are specialized factory and aftermarket parts specifically designed for off-roading, such as suspensions, bumpers, bull bars, tires, and locking hubs. For drivers who do casual or professional off-road driving, all of these specially designed off-road parts are crucial in keeping their vehicles in good shape.
The locking hub, for example, plays an important role in balancing fuel efficiency and performance by means of locking and disconnecting the front wheels from the axle. Locking hubs are commonly found on older 4x4 trucks and SUVs, though some modern 4-wheel drive (4WD) vehicles are still equipped with one.
What is a locking hub?
Locking hubs, or free-wheeling hubs, are typically installed on the front wheels of 4-wheel drive vehicles. They are designed to lock and “free” the wheels from the front axle when switching between 2WD and 4WD. Once disconnected or unlocked, the wheels spin freely, which in turn decreases mechanical resistance. Unlocking the hubs may result in slightly better fuel efficiency when 4WD is not in use. Depending on the type of locking hub you use, it may automatically engage when you switch to 4WD or you may have to manually twist a dial to lock your wheels.
Types of locking hubs
Engaging and disengaging a locking hub depends on which type of hub you have on your vehicle. Basically, there are two types of locking hubs: manual and automatic. Here’s how you can differentiate the two.
Manual Locking Hubs
4WD trucks and SUVs with manual locking hubs (often older models) are commonly referred to as “part-time” 4x4. The term part-time describes the ability of the front axle to rotate freely like on a regular 2WD vehicle. This type of locking hub is manually operated by hand, meaning you have to hop out of the vehicle and twist a dial to lock or free the wheels before you can engage the 4x4 system.
Automatic Locking Hub
Automatic locking hubs can lock and free on the fly, negating the need to step out of the vehicle and twist the dial by hand. Automatic locking hubs feature a one-way clutch locking mechanism that’s operated through the help of inertia. When the driveshaft applies torque, the hub is forced to slide in and lock in place. There are two designs of automatic locking hubs, which are internally and externally retaining types.
Which locking hub type is better?
Manual locking hubs feature a relatively simple mechanism compared to the automatic type. This means there are fewer parts that can go bad inside the assembly. In addition, they are considered as heavy-duty locking hubs due to their durability. On the flip side, manual locking hubs can’t match the convenience brought by automatic locking hubs. Auto-locking hubs can engage and disengage either on the fly or by putting the gear in neutral position first. Basically, it would depend on your preference as you’re looking at convenience versus ease of maintenance.
Locking hub facts you should know
There are a few things you need to know if you own a part-time 4x4 or 4WD vehicle that uses locking hubs. The following pieces of information should help you keep your locking hubs in tip-top condition.
Locking hubs need regular inspection
Locking hub maintenance is important, especially after recent exposure to water or mud. To avoid damaging your locking hubs, you need to get rid of any mud or corrosion build-up after they are submerged in water. To do this, you need to remove and disassemble the locking hub, which is not an easy task. Review your vehicle owner’s manual or visit your trusted mechanic to ensure proper disassembly and re-installation.
You can change from manual to auto or vice versa
Not content with the type of locking hub assembly on your vehicle? Don’t worry, as there are locking hub conversion kits available so you can swap your factory automatic locking hub with a heavy-duty manual type or vice versa. Locking hub conversion kits are priced anywhere between $100 and $250.
Locking hubs are not serviceable
Locking hub maintenance is important because they are not serviceable. If one of your locking hubs goes on the fritz, you will need to replace it. How you replace the locking hub would depend on the type installed on your vehicle. Remember to do your research before you work on your locking hub, though you can always let a certified mechanic do the job for you.
When should locking hubs be replaced?
Locking hubs are subjected to much wear and tear, especially if you do a lot of off-road driving. Some signs that your locking hubs need replacing are:
- Four-wheel drive is not engaging - One or both of your front wheels may not pull
- Grinding noises while driving
- Unable to disengage the four-wheel-drive - the hubs may make loud popping noises in this case
Symptoms of a bad locking hub
Locking hubs are essential components of your vehicle’s 4WD system. They ensure proper operation of the front wheels when the 4x4 drivetrain is engaged. Driving with a badly-damaged locking hub could affect your vehicle’s 4WD performance. Take note of these symptoms of a bad locking hub to avoid any problems.
Difficulty engaging the system
One of the most common symptoms of a failing locking hub is when it does not engage properly. Having a damaged locking hub may cause a wheel to not pull despite switching to 4WD mode a couple of times. Your wheel could just rotate freely and fail to give your vehicle enough pull to successfully traverse a rocky or muddy terrain.
Stuck on locked mode
A locking hub that won’t disengage no matter how hard you try obviously needs a replacement. If the component fails to disengage, the vehicle will continue to pull with four wheels. You may also hear popping noises from the hub as a result of this problem. However, do note that this popping noise doesn’t always mean your hubs are out of commission. Some vehicles require reversing to disengage the locking hub. Try reversing at least six feet and see if the hubs free the wheels. If not, then you’ve got a problem.
Weird noises coming from the hub
Another symptom of a bad locking hub is an abnormal noise coming from the hub. Grinding noises are often produced when one of your locking hubs is in bad shape. Usually, the noise would come from the side of the good hub right after the damaged side fails to engage.
What other factors are considered in choosing locking hubs?
- Compatibility - Make sure that the locking hubs you will order have the right specifications for your vehicle. Your owner's manual should have all the specs you need in finding replacement parts.
- Installation - It is possible for you to save money by replacing the locking hubs yourself. After ensuring that the replacement parts you ordered are compatible with your vehicle, see to it that they come with an installation manual and all components you need for the job.
How much is an OE replacement locking hub?
Finding a high-quality OE replacement locking hub is easy if you visit CarParts.com. Thanks to exclusive discount promos, you can get a quality locking hub for as low as $30. Meanwhile, higher-quality locking hub assemblies, pairs, and kits cost around $50 to $2,000. With the website’s extensive list of parts from the most reputable brands across the country, you wouldn’t have to worry about not getting the right fit. Simply indicate your vehicle’s year, make, and model on the filter tab under the search menu.
New Locking Hubs in 4 Steps
Locking hubs allow you to easily change your vehicle between a two-wheel drive and a four-wheel drive. After a few years of service, there may be a build-up of grease, rust, along with regular wear and tear that may require you to replace this part. The installation and removal of the new hubs is not as difficult as you think. Though these are a vital part of a car's drivetrain, it is a very feasible project that requires only a basic grasp of mechanical knowledge.
Required skill level: Novice
Needed tools and materials:
- Floor jack
- Jack stands
- Wrench set (Allen, lug, ratchet, torque)
- New locking hubs
Preparing the car and materials
Gather the tools and materials needed for the repair. Inspect the kit of your new locking hubs to make sure it's complete and compatible for your car. A comprehensive kit should include all the necessary hardware for easy installation. Park your car on a level surface. Raise it with a floor jack and safely secure with jack stands. Use a lug wrench to remove the front wheels.
Removing the old locking hubs
It's advisable to work on one wheel at a time. Leave the other side to serve as a guide for proper installation. Use an Allen wrench to remove the six, small bolts securing the old hubs in place. This exposes the other internal parts that have to go as well. The exact parts to be removed depends on your car and the type of hub you will install (manual/automatic/flange). Refer to the locking hub's manual for specific instructions.
Installing the new hubs
Most replacement locking hubs are made of a cap and the main assembly. For the main assembly, install the o-rings, washers, bolts, and studs on the wheel according to the supplied instructions. There is an exact torque setting on the bolts that depend on your car's model. Cover with the cap and return the Allen bolts. Switch between the free and locked position to try and mesh the hub properly. Return the wheel. Do the same removal and installation process for the other side.
Testing the engagement and disengagement
Put the hubs in the lock position and spin the wheels. You'll know it's properly on when the driveline turns as well. For disengagement, put the hubs in the free position. If the wheels are spun, the driveline shouldn't spin with it, and there shouldn't be any odd sounds.
Replacing Your Locking Hubs
The locking hubs fitted on your front wheels are what allow you to use your vehicle's 4-wheel driveability. However, your locking hubs are subjected to a lot of stress, especially during intense off-road trips. When they get too worn out or when they breakdown completely, you will need to replace them immediately. Fortunately, replacing your locking hubs can be easy when you have the right tools and basic mechanical skills.
Difficulty Level: Moderate
Here's what you'll need:
- Floor jack
- Jack stands
- Lug Wrench
- Assortment of wrenches (depending on your vehicle)
- Snap ring pliers
- New locking hubs
- Work gloves and other personal protective equipment
- Make sure your vehicle is on a level surface - it might roll or lean when jacked up.
- Never on just the floor jack to hold up your vehicle. Be sure your jack stands are properly placed.
- We recommend working after your vehicle's engine has cooled down.
- This is a general guide. Refer to your owner's manual for any specifications.
- Place your vehicle in "Park" or "Neutral" before you begin.
Step 1: Loosen the lug nuts on the front wheels (without removing them).
Step 2: Use the floor jack to raise the front of your vehicle. Set up the jack stands.
Step 3: Fully remove the lug nuts and the front wheel at the driver's side of the vehicle.
Step 4: With the appropriate wrench, remove the hub cover.
Step 5: Locate the two snap ring holes and use the snap ring pliers to pull out the snap rings.
Step 6: Remove the six nuts that attach the hub body to the axle. Pull out the locking hub.
Step 7: Install the new locking hub assembly. Use the snap ring pliers to fasten the snap rings into place.
Step 8: Restore the hub cover and the wheel by reversing the removal procedure.
Step 9: Repeat Steps 3 to 8 on the passenger side.
Step 10: Remove the jack stands and lower your vehicle. Tighten the lug nuts to its specified torque.
The whole procedure shouldn't take more than an hour for an experienced DIYer. Now you can get back to enjoying the full power of 4-wheel driving!