On a front wheel drive car, the front wheel assembly consists of the bearings, hub and in many cases, the sensor for the anti=lock braking system. If you are the owner of a car with front wheel drive and you sense the bearing is about to fail, at the same time your mechanic checks the condition of the bearing, he should check the condition of the hub.
The wheels on any vehicle are the most important part, without them the car would be little more than an expensive sled. If any of the components that are integral with the function of the wheel are damaged or worn out then the free movement of the wheel will be jeopardized.
The wheel hub assembly:
It is the front wheel assembly that ensures the car handles well. The hub is centrally located in the wheel; it acts as the interface between the rigid car suspension and the rotating wheels. The hub has fasteners on both sides, on the side which is stationary against the suspension there is usually a three or four bolt flange, on the wheel side there are studs which match the bolt pattern of the wheel.
Between the two elements there are wheel bearings, without them the wheels simply would not turn even though they may be fastened to the hub.
It is not difficult to tell when a front wheel assembly is wearing or about to fail. It will start with a humming or roaring sound coming from the wheel area. It is always a good idea to replace the entire assembly rather than just the bearings.
As every vehicle has a different style of wheel hub based on the design criteria it is important that it be replaced with an identical unit. Pay particular attention to the bolt holes on the one side and the wheel studs on the other, the patterns must be identical otherwise it will not fit. The quality of the bearings is of the utmost importance; make sure the front wheel assembly that your mechanic installs uses well known, high precision bearings.