Dirt combines with the oil used to lubricate a clock and then, as the oil dries out, an abrasive forms. As the wheel continues to turn, the abrasive grinds away at the pivot. Below you will see an extreme case of what occurs when this happens. Unfortunately, the photographer (me) neglected to take a photo of the pivot after it was polished. I will take another set of photos when I do my next overhaul. As you can see, if left as is, this pivot would cause rapid damage to its bushing and would not have a smooth even surface upon which to turn. This would affect the ability of the clock to keep good time.
