A ball bearing and to a clutch thrust bearing device including such a bearing. The invention also relates to a driveline system including such a device, the system being provided to an all-wheel drive driveline system of a motor vehicle. The ball bearing comprises a fixed inner ring able to bear against an axially movable piston, a rotatable outer ring, and one series of balls between the rings. The rotatable outer ring further comprises a shield provided with a folded flange able to bear against a resilient biasing member.