The stability is probably the most important
function of a wheel bearing. One could say, that a wheel bearing is good if the driver doesn't notice it far a long time. In addition, it should offer a low friction resistance and be as easily replaced as possible.
The wheel bearing shown above does not yet represent an example which can be applied to the average vehicle. This example is screwed onto the (grey) wheel bearing housing. Mostly they are fitted and, e.g., secured by two circlips. In this case, the replacement requires much more effort. Because the specific warming can be quite a problem, the most likely solution is the complete dismounting of the housing, and then driving the bearing out using a hydraulic press. In the above figure, one only needs to loosen the screws on the bearing housing and on the axle drive shaft.
The basic construction consists, in principle, of two inclined ball-bearings with separate inner rings (light blue), and a common outer ring (light green). Thus, the bearing can take up both axial and radial forces. In this picture, the brake-disc and the wheel-hub (dark red) have been left out. As opposed to many wheel bearings on non-driven wheels, this bearing has no adjustment possibilties. It does however, hold the central mountings of the axle drive shaft. For the sake of simplicity, all the bolt heads in the picture are shown with outside hexagonal heads, in reality, this is not the case.