Summary of Key Points:
- Wheel bearings reduce friction and bear the weight of your vehicle while you drive.
- Before vehicles had wheel bearings, many carts and wagons used thru-axle or trunnion systems—which allowed wheels to turn but created significant friction.
- Early wheel bearings came in the form of journal bearings or roller bearings, which used lubrication or the increased surface over which a vehicle’s weight was distributed to reduce friction. More efficient types like ball bearings and tapered bearings became more prominent later in the 20th century.
- Modern wheel bearings are usually part of a hub assembly, which is a single unit containing the wheel hub, inner and outer bearings, and other components like seals and sensors. Purchasing high-quality aftermarket hub assemblies for your vehicle can help you enjoy a smoother, safer, and more comfortable driving experience.
Wheel bearings help the wheels of your vehicle rotate smoothly and with minimal friction, making it safer and more comfortable to drive. But wheel bearings have gone through numerous changes in their history, and modern versions offer many benefits you won’t get from older components.
The more you know about how wheel bearings work and how they’ve evolved, the better prepared you’ll be to buy reliable new ones when the bearings you have wear out and need to be replaced. As providers of superior aftermarket wheel bearings for many makes and models, we know all about wheel bearings—read on to get a quick history lesson from us.
Life Before Wheel Bearings
Before the invention of wheel bearings as we know them, other types of technology were used to support the weight of vehicles and allow their wheels to rotate. Here are a few of the most common examples:
The most common method was the use of a solid wooden spindle that passed through the center of the wheel. This system was used long before the development of automobiles—going back as far as carts and chariots used by ancient Mesopotamian and Egyptian civilizations.
The spindle in these systems was supported by the vehicle's frame, and the wheel was mounted on the spindle using a series of wooden or metal pegs or pins. These systems had some limitations and often resulted in a rough ride, as the wooden spindle would wear down quickly and the pins would loosen. Additionally, the wooden spindle would absorb the water and swell in the wet conditions, which would make it difficult to rotate the wheels.
Another technology that was used before wheel bearings were invented is the "trunnion" system. This system uses a trunnion (a cylindrical projection) attached to the wheel hub, which rests on a pivot point on the vehicle's frame. The trunnion system provided a smoother ride than the thru-axle system but still had its limitations, such as the added friction and wear on the pivot point.
In both of the above systems, the wheels were not able to rotate freely and easily, which caused a lot of friction and wear on the wheels, axles, and other components of the vehicle. The invention of wheel bearings greatly improved the smoothness and efficiency of vehicle operation by allowing wheels to rotate freely and with minimal friction.
Early Wheel Bearings
Early automobiles used various different types of wheel bearings. Some used plain bearings similar to those in carriages and wagons (described above), but the additional weight and forces generated by motor vehicles required new developments in wheel bearing technology as well.
Via KTU Web on YouTube.
Journal bearings were first developed in the late 19th century, and consist of a shaft or journal that rotates inside a stationary housing or sleeve. The journal and the housing have matching shapes (usually cylindrical) and are separated by a film of lubricant like oil or grease. The lubricant cools the bearing while reducing friction and wear between the journal and the housing.
Some early automobiles also used roller bearings, which came into prominence at the start of the 20th century. These bearings consist of small cylindrical rollers held in place by a cage and reduce friction by distributing the vehicle’s load over a larger surface area.
Common 20th Century Wheel Bearings
As the 20th century stretched onwards, the automobile industry went through major changes. Cars became heavier and faster—requiring bearing types that could handle even more friction. Although ball bearings and tapered bearings had existed for some time, they became much more common during this period.
Ball bearings consist of small balls that are held in place by a cage and reduce friction by distributing the load over a larger surface area. They were first used in the front wheels, where the load is relatively light and the speed of rotation is relatively high. Today, most ball bearings are used in steering columns, although a few still remain in wheels for light-duty vehicles.
These bearings have tapered rollers instead of the cylindrical ones found in roller bearings, and are designed to handle large loads in one direction. They also have a conical shape, with the larger end of the cone on the inner ring and the smaller end of the cone on the outer ring—allowing them to handle radial and axial loads.
Like ball bearings, tapered roller bearings were first used in the front wheels of automobiles. While not commonly used in wheels any more, they were an important step towards current wheel bearing technology.
Modern Wheel Bearings: The Hub Assembly
The use of tapered roller bearings in front wheels eventually led to the development of the hub bearing unit, which is the most common format for vehicle wheel bearings today.
Hub assemblies are single units that integrate the wheel hub and bearing (usually a tapered bearing for early models). The advantages of hub assemblies are:
- Easier to install, maintain, and replace
- Better protection of the bearing from dust and debris
- Better heat dissipation
Current Hub Assemblies
As the automobile industry progressed, manufacturers began to experiment with new types of bearings and lubrication systems to improve performance and reliability. Today, high-quality hub assemblies like the ones we sell often consist of the following components (depending on the make and model of the vehicle they’re designed for):
- Hub: the portion of the assembly that connects the wheel to the axle
- Outer bearing: bearings that hold the weight of the wheel during rotation
- Inner bearing: bearings located inside the hub that hold the weight of the vehicle
- Seal: the part of the assembly that keeps dirt and water away from the bearings
- ABS Sensor: a device that monitors the wheel’s speed and activates the ABS to prevent wheels from locking up while breaking
- TPMS sensor: a device that monitors tire pressure and alerts you when yours is low
Get Your Bearings with Our Quality Replacement Parts
Modern wheel bearings are designed to handle higher amounts of force than older versions, but that’s not all. Our best-in-class aftermarket hub assemblies are also designed to last longer, with better seals to prevent them from failing prematurely and ABS rings that eliminate false signals so you can enjoy the smoothest possible ride.
Browse our online parts catalog to find the best hub assembly for your vehicle—and feel free to contact us if you have any questions about the products we sell! We’ll be happy to tell you all about our hubs and bearings so you can order replacements for your vehicle with confidence.