Mechanical Clock Movement Issues
Mechanical Clock Movement Issues arise after years go by because the oil turns solid. With age, the mechanical clock movement's oil solidifies and becomes black and sticky. By the time 20 or 30 years go by, the oil has solidified and is creating wear on the movements brass plates.
If you look at your old clock movement, you will see holes in the brass plates where there are small pivot arbors sticking into these holes. These pivots are what the gears of the clock ride upon and as the pivots spin in the solidified oil, this makes the holes oblong instead of round. With the pivot holes oblong, the holes are pinching the pivots and creating resistance in the gear train. With the solidified oil and the pinched pivots, the clock will eventually stop working or chiming.
This wear takes place in the holes that are in the brass plates and is hard to identify sometimes. These holes in the brass plates become oblong instead of round and this pinches the pivot arbor going into it. Between this, and the solid oil, the clock ceases to function. To have this repaired is an expensive and long process. To have a mechanical movement serviced can cost two times as much or even three times the amount of the new one.