[Werner]

Hallo und guten Tag.

I also cannot imagine that the inner or outer ball bearing rings are used with a sliding fit. When I was still in quality control at Ford (40 years ago), the rear axle bearings were pressed together with a hard press fit with an oversize of 8 µm. This is the way to avoid uncontrolled twisting of the outer and inner rings.

The wear of the ball bearing all around has its origin in the typical rolling bearing construction. In the long time course of the innumerable revolutions, the surfaces of the balls and their track path gradually harden, they become "brittle". At some point, a tiny dot breaks off on the surface of a ball. This now rough ball shaves off the track and therefore gradually all ball faces and the bearing grooves are rough and the ball bearing is totally destroyed.