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Unitized Wheel Bearing


Unitized Wheel Bearing

Unitized Wheel Bearings, also known as hub unit bearings, are integrated bearing units in modern automotive wheel hub systems. They are designed to enhance vehicle safety, performance, and ease of maintenance. Hub bearing units are categorized into first-generation, second-generation, and third-generation types.

Product List

Unitized Wheel Bearing Generation 1

Unitized Wheel Bearing Generation 1

The basic structure of unitized wheel bearing generation 1 typically consists of a double-row angular contact ball bearing or a double-row tapered roller bearing. The inner and outer rings of the bearing are integrated into a single unit, but there is no mounting flange. These bearings need to be press-fitted with the hub and shaft and are usually secured using a circlip or a fastening nut.

Features:Simple Structure, Lower Cost,Suitable for Various Vehicle Models and Applications

These bearings are still utilized in some economy and light-duty vehicles, particularly in early car models.

Unitized Wheel Bearing Generation 2

The Unitized Wheel Bearing Generation 2 is based on the first-generation bearings but incorporates an additional mounting flange, typically an outer flange, used for attachment to the suspension system. The flange usually features bolt holes for easy installation and removal. The internal design can consist of either double-row angular contact ball bearings or double-row tapered roller bearings.


  • The installation process is simplified, reducing installation time.
  • Enhances the overall rigidity and stability of the bearing.
  • Reduces the sensitivity of the bearing to assembly errors.


Unitized Wheel Bearing Generation 2 Primarily used in passenger cars, light commercial vehicles, SUVs, and crossovers, providing high precision, high stability, and high load capacity.

Unitized Wheel Bearing Generation 3

Unitized Wheel Bearing Generation 3

Unitized Wheel Bearing Generation 3 builds upon the second-generation bearings by adding a mounting flange (usually an inner flange) for securing to the axle. The internal design typically consists of a double-row angular contact ball bearing or a double-row tapered roller bearing. These bearings can integrate Anti-lock Braking System (ABS) sensors or other electronic devices, providing additional functionality.


  • Simplified installation and removal process, offering higher integration.
  • Provides increased rigidity and stability, suitable for high-performance and heavy-duty applications.
  • Can integrate more functions, such as ABS sensors, enhancing vehicle safety and performance.


Unitized Wheel Bearing Generation 3 Primarily used in high-performance vehicles, heavy commercial vehicles, luxury cars, and electric vehicles, providing higher integration, ease of installation, and additional functions (such as ABS sensors).


Unitized wheel bearings integrate multiple components such as the bearing, flange, and sensors into a single unit, simplifying the installation and maintenance process. Compared to traditional separate wheel bearings, unitized wheel bearings offer higher integration, reducing installation time and complexity while providing greater stability and performance.

Most modern unitized wheel bearings are designed to be maintenance-free. They are pre-lubricated with grease and sealed to prevent contaminants from entering. This means they typically do not require re-lubrication or special maintenance during their service life. However, regular inspections to ensure seal integrity and normal bearing operation are still necessary.

The time and cost to replace unitized wheel bearings vary depending on the vehicle model and specific circumstances. Generally, replacing a unitized wheel bearing takes about 1-2 hours. The cost includes parts and labor, so it's advisable to contact a professional repair shop for an accurate quote and ensure the use of high-quality bearings and professional service.

Common faults of pillow block bearings include wear, overheating, poor lubrication, and contamination. Preventive measures include regular lubrication, maintaining a clean working environment, regularly inspecting the bearing condition, correct installation, and avoiding overloading. Timely maintenance and care can effectively extend the bearing's service life.

Industry Applications

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