Looking after your clock
Small electric motors are not worth rewinding, replace them.
Many clocks have a clutch to enable the hands to be moved independent from the mechanism DO NOT OIL THE CLUTCH OR IT WILL SLIP AND THE CLOCK WILL LOSE TIME.
If you have a mechanical clock and it is serviced regularly you can lightly oil the gear wheels, but if it is not serviced regularly and in a dirty place, keep the gear wheels dry to avoid dirt mixing with oil to make a grinding paste which will prematurely wear the gear wheels.
ENEMY No.1 DIRT
Mechanical clocks can last centuries, and a dirty clockroom is the equivalent of cancer, slowly working the dirt into the bearings, changing into a grinding paste and wearing away metal. Lost metal is lost clock, CLEAN CLEAN CLEAN the clockroom.
ENEMY No. 2 LACK OF CARE
Do not forget your clock, think of it at least twice a year. Would you run your car without a service, without oil, without repair. Then do not expect your clock which works every second of every day of every year to work without the same and more attention. CARE FOR IT OR LOSE IT.
Electric motors need very little maintenance, but the gear box, connecting rod ends which have universal connectors and bearings to the hands and dial will need cleaning and lubricating.
Mechanical clocks need every bearing and pivot to be cleaned and oiled, sliding surfaces greasing, and most other parts wiping over with an oily cloth.