Ball Joint vs. Wheel Bearing: Understanding the Differences and Importance

Do you know about the ball joints and wheel bearings of your vehicle’s suspension system? These two components work together to provide a smooth and stable ride. Also, they keep the wheels moving and prevent unnecessary wear and tear.

Especially, if you are a driver, your and passengers’ safety depends on these two parts. In short, ball joints link the steering knuckle to the control arm. Alternatively, a wheel bearing allows the wheel to rotate freely.

Today, I have selected ball joint vs. wheel bearing as the topic of discussion. After reading this article, you will know about their differences, importance, and signs of required replacements.

Definitions – Ball Joint & Wheel Bearing

You can learn about the basics of ball joints and wheel bearings in this part.

What are Ball Joints?

A ball joint is a small, spherical bearing but a vital part of a car’s suspension system. Functionally, ball joints work as a pivot point between the steering knuckle and the control arm. Therefore, the wheels can move up and down while the suspension compresses and decompresses. You can also move your car’s wheels to the left and right.

They are spherical hardened steel bearings that allow for movement in all directions. They enable the steering and suspension to work correctly. Also, they can absorb the impact of bumps and vibrations besides wheel movement.

You can find these ball joints in the lower part of the front suspension system. But some vehicles may have ball joints in their rear suspension system too. However, they can handle large amounts of weight and stress for their unique design. Still, if a ball joint fails, it can cause the wheel to become misaligned.

What are Wheel Bearings?

You can find wheel bearings within the wheel hub assembly. Small steel balls are placed inside a metal ring (known as a race). Again, you can find a hollow metal piece at the wheel’s center (hub). The wheel bearings securely get placed in the hub. They ride on an axle shaft made of metal.

Wheel bearings support the weight of the vehicle like ball joints. You can rotate wheels smoothly and reduce friction between the wheel and axle for these components.

A wheel bearing typically has steel or ceramic construction. You can find it in versatile sizes to match your vehicle’s preferences. Thus, you may get problems like wheel noise, steering instability, and even wheel separation over time.

Both ball joint and wheel bearing typically remain in good condition for a long time. Still, constant use and exposure to dirt, water, and other elements can wear them out. Once the wear happens, you will experience uneven tire wear, instability, and even complete loss of steering control.

Functions – Ball Joint Vs. Wheel Bearing

Now, you will learn the differences in functions regarding ball joints and wheel bearings. If you know them, you can diagnose and repair suspension issues.

How Do Ball Joints Work?

Think about the human hip joint! A ball joint is identically the same: a ball-in-socket joint. The ball is a smooth sphere at the end of a shaft. Again, the socket is a concave cup in the suspension component it connects to.

Without any hip joint, we cannot move our legs in any direction. In short, our leg movement could be very constrained. This same scenario goes with ball joints.

A suspension system experiences various forces to make wheels turn in different directions. Ball joints enable this movement by letting the steering knuckle spin on the control arm. Consequently, you can maintain the vehicle’s proper alignment and steering control.

Generally, there are two main types of ball joints: load-bearing ball joints and non-load-bearing ball joints.

  • Load-bearing ball joints are typically found in the lower control arms. They can carry the vehicle’s weight while supporting the steering and alignment.
  • Non-load-bearing ball joints are commonly found in the upper control arms. They provide additional steering control and alignment support.

How Do Wheel Bearings Work?

Wheel bearings help to rotate the wheels smoothly with minimal friction. Technically, a wheel bearing refers to a set of small, metal balls enclosed within two rings (races). It is inserted into the hub assembly of a wheel. Also, it allows the wheel to rotate freely around the spindle or axle, reducing friction between the wheel and axle.

Rolling contact is a phenomenon that defines the function of wheel bearings. When the wheel rotates, the metal balls inside the bearing roll along the inner and outer races. Consequently, those balls create a smooth, rolling motion that minimizes friction. The phenomenon can reduce the generated heat to prevent premature wear and failure.

You can find two primary types of wheel bearings: tapered roller bearings and ball bearings.

  • Tapered roller bearings are commonly used in heavy-duty vehicles like trucks and buses. They can handle high radial and axial loads.
  • Ball bearings are typically used in lighter vehicles and provide better resistance to side loads.

Importance of Healthy Ball Joint & Wheel Bearing

You will learn about the advantages of these two components for why a vehicle should have them in the right condition:

The necessity of Ball Joints

Healthy ball joints offer multiple benefits. They are:

Improved Handling

You can handle the vehicle well if the ball joints remain fine. After all, they offer a greater range of movement in the suspension system. So, you can gain better steering response and stability.

Longer Lifespan

Ball joints have a longer lifespan compared to other suspension components. So, they can save money in the long run if you maintain them well.

Better Performance

Healthy ball joints can perform better by reducing friction and wear in the suspension system. So you can achieve a smoother ride and improved overall driving experience.

Easy Maintenance

Ball joints are relatively easy to maintain. You can easily replace them if they become worn or damaged.

Wide Availability

You can find suitable ball joints at nearby stores. Also, they are available for different models of vehicles.

The Necessity of Wheel Bearings:

Like ball joints, wheel bearings in good condition may offer multiple benefits. They can be:

Smooth Ride

Wheel bearings reduce friction between the wheel and axle. If you keep them fit, they can provide a comfortable ride.

Improved Performance

High-quality wheel bearings can improve vehicle performance by reducing the energy required to turn the wheels. As an effect, you can save more fuel for a long time.

Increased Durability

A properly installed and maintained wheel bearing can last for many years. It refers to fewer repairs and lower maintenance costs.

Enhanced Safety

Faulty wheel bearings can lead to unpredictable handling and even wheel failure. So, replacing worn or damaged bearings can help improve vehicle safety.

Symptoms of Failing Ball Joints and Wheel Bearings

How do you know if your ball joints or wheel bearings are malfunctioning? Well, you will learn about them in this part.

Signs for Ball Joint Replacement

If you experience any of these, you may need to replace the ball joints soon:

Clunking or Knocking Noise

A worn or damaged ball joint can cause a clunking or knocking noise when you drive over bumps or uneven surfaces. You may hear this noise more when you turn or corner the wheels.

Steering Wander

A worn ball joint can cause the vehicle’s steering to feel loose or wander, especially at high speeds. You may face difficulties controlling the vehicle. Also, the risk of an accident may increase.

Uneven Tire Wear

Another consequence of a damaged ball joint is causing uneven tire wear. It is because the wheels may not be properly aligned. Therefore, you will need premature tire replacement. Even decreased fuel efficiency will appear over time.

Vibration or Shaking

Suppose your car or truck vibrates or shakes while driving, especially at higher speeds. Then, it is high time to provide immediate attention to the sign of a severe ball joint issue.

Steering Stiffness

If the ball joint is damaged, you may find the steering has become stiff or difficult to turn. Hence, there will be less control over the steering.

Signs for Wheel Bearing Replacement

The following are some common signs and symptoms that may indicate the need for wheel bearing replacement:

Grinding or Humming Noise

The inner side of the wheel bearings is packed with grease. It helps to keep everything moving freely. Over time, this grease leaks or degrades. Thus, wheel bearings will produce excess heat and put stress on them. Then, they get damaged gradually and create unexpected noise. It is a warning to replace the wheel bearing. This noise may be more pronounced when turning or cornering.

Steering Problem

A worn wheel bearing can cause the vehicle’s steering to feel wobbly. When you drive the car at a higher speed, this condition becomes worse. Likewise, it makes the car more difficult to control and reduces driving safety.

Uneven Tire Wear

Worn wheel bearings have a loose fit inside their housing. So, when you drive, the wheels will wobble to and fro unnecessarily. You may not feel it in the steering wheel. But checking out the tire tread, you may find one side is more worn. It happens due to faulty wheel bearings.

Vibration or Shaking

Like a ball joint, a defective wheel bearing can also cause the vehicle to vibrate or shake when you drive. You may experience it more when you are in a rush in your car.

ABS Warning Light

A faulty wheel bearing can trigger the ABS warning light on the dashboard in some vehicles. It indicates that there is an issue with the wheel speed sensor. And this sensor is often placed within the wheel bearing assembly.

DIY Replacement

In this part, you will learn how to replace the ball joint and wheel bearing by following easy steps:

Tools Required

  • Brake cleaner
  • Ball joint separator tool or press
  • Cotter pins
  • Castle nuts
  • Grease gun
  • Jack and jack stands
  • Lug wrench or socket set
  • Replacement ball joints or wheel bearings
  • Torque wrench

How to Replace Ball Joint and Wheel Bearing at Home

Park your vehicle on a level surface and engage the parking brake first. Then, these steps to replace any defective ball joint or wheel bearing at home:

Loosen the Lug Nuts

Take the lug wrench or socket set and start using it to loosen the lug nuts on the selected wheel.

Jack Up

Jack up the vehicle and support it securely on jack stands.

Remove Things

Start removing the wheel and brake assembly. Also, remove the cotter pin and castle nut from the ball joint or wheel bearing.

Use Ball Joint Separator Tool or a Press

Use a ball joint separator tool or a press to remove the components from the steering knuckle. Hence, ensure supporting the steering knuckle during this process. It will prevent damaging the brake hose or other parts.

Clean & Inspect

Clean the steering knuckle and inspect it for wear or damage.

Install New Parts

Install the new ball joint or wheel bearing after seating them correctly. You may use a torque wrench to tighten the castle nut. Then, install a new cotter pin and bend it back to prevent it from coming out.

Use Grease

Use a grease gun to fill the ball joint or wheel bearing with grease. You should read the manual first to know the recommended type and amount of grease.

Reinstall the Assembly & Finish the Job

Reinstall the brake assembly and wheel. You can use a torque wrench to secure the lug nuts. Lastly, lower the vehicle and test drive to ensure proper operation.

Final Words

Let me repeat the facts!

Ball joint vs. wheel bearing is an exciting topic, as we are often confused over these two things. But I have tried to focus on each component more intensively. Now, you know the differences between them well. You can also identify any issue with wheel bearings or ball joints.

Try to follow the signs I have described and treat them by following the instructions. After all, neglecting worn ball joints and wheel bearings can lead to serious safety hazards.

Thanks for reading this long post. Have a nice day!

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