A valuable feature of hydrodynamically lubricated plain bearings is that they should generally have infinite lives. If they are subjected to heavy cyclical loads, they will eventually crack and fail from fatigue, and if they are subjected to heavy vibration forces, the lubrication film could break down, but with normal operating conditions and reasonably clean lubricants, they should last essentially forever.

Tip from Failure Analysis Made Simple: Bearings and Gears