What is the assembly component of the rear wheel hub of a car?
The rear wheel hub assembly component, usually referred to as the hub assembly or hub bearing unit, is a key component that connects the wheel to the chassis system, performing core functions such as bearing weight, rotating, steering, braking, and power transmission.
According to the latest publicly available information (as of April 2026), the typical structure and composition of this component are as follows:
Main components of the hub assembly
Hub body: Supports the tire and is connected to the rim via hub screws, serving as the foundation for the entire wheel.
Hub bearing: Supports the high-speed rotation of the wheel. Modern models generally use integrated hub bearing units, featuring maintenance-free, pre-tightened lubrication, and high reliability.
Sealing component: Prevents dust and moisture from entering the bearing and also prevents lubricant leakage. It often adopts a double lip rubber sealing structure.
ABS sensor ring (for some models): Works in conjunction with the ABS/ESP system to provide wheel speed signals.
Flange/Installation surface: Used for connection with brake discs, half shafts, or suspension systems.
Technical evolution and types
Hub bearings are classified into three generations based on integration:
First generation: Separate double-row bearings, requiring separate installation onto the hub and steering knuckle, with complex assembly.
Second generation: Semi-integrated, with the inner ring of the bearing integrated with the hub and the outer ring with a flange, simplifying installation.
Third generation: Fully integrated unit, with the bearing, hub, flange, and ABS sensor ring integrated, directly installed onto the steering knuckle via bolts, being the current mainstream.
Function and importance
Bear the vertical load (radial force) of the vehicle and the axial force during steering/braking.
Ensure precise rotation of the wheel, affecting steering stability, braking response, and noise control.
If worn or failed, problems such as abnormal noise, steering shake, ABS false alarms, and deviation may occur.
Note: In some contexts, "hub" refers only to the rim (including the rim and spokes), while "hub assembly" or "hub assembly" includes all the integrated components mentioned above. When repairing or replacing, it is recommended to use the original factory-level or compatible specialized hub assembly to ensure safety and performance.
If the rear wheel hub assembly component of a car is damaged, it is necessary to determine whether to repair or replace based on the extent of the damage. The following are key processing steps and precautions:
I. Determine whether to replace
Replacement conditions:
Cracks or fractures in the hub (especially through structure)
Severe deformation that cannot be corrected by professional equipment
Severe imbalance in the balance test and inability to adjust
Obvious shaking or deviation when the vehicle is driven after installation
Repairable conditions:
Surface scratches, abrasions, yellowing
Edges with notches or small dents (not affecting structural strength)
Minor distortion but without cracks, can be repaired with a correction machine
If unsure about the extent of the damage, it is recommended to contact a professional repair shop for assessment as soon as possible to avoid safety hazards.
II. If replacement is needed, the following steps are as follows
Preparations
Tools: Jack, tire wrench, socket wrench, torque wrench (as per manual requirements)
Location: Choose a solid and flat surface, apply handbrake, and turn off the ignition switch
Dismantle the old hub
Loosen the tire bolts (in a diagonal sequence)
Use a jack to lift the vehicle, support it at the specified support points
Remove the tire, then remove the hub bolts (also in a diagonal sequence)
Install the new hub
Clean the installation surface (brake disc, axle flange), remove oil stains and rust
The parameters of the new hub (diameter, pitch, offset, center hole) must match the original factory
After manual pre-tightening of the bolts, gradually tighten them in multiple stages at the diagonal points to the specified torque
Check after installation Install the tires and conduct a dynamic balance test (to prevent high-speed wobbling)
Lower the vehicle and re-tighten the tire bolts
Test the vehicle to check for any abnormal noises, vibrations or excessive shaking
If you want to know more, keep reading the other articles on this site!
Please call us if you need such products.
Zhuo Meng Shanghai Auto Co., Ltd. is committed to selling MG&MAXUS auto parts welcome to buy.
