All manufacturers suggest that mechanical clocks have periodic maintenance. Some manufacturers suggest yearly, while others suggest ever two or three years, with a professional cleaning every five years. It has been my experience that a clock will get enough dust in the oil to require maintenance every two years. Excessive wear occurs when the oil in the clock dries out and the clock runs for an extended period of time without lubrication. Many clock owners believe they are lubricating their clock by removing the side access panels and oiling the pivot points they can see and reach. However, this allows for missed lubrication points and general inspection behind the dial. In order for a clock to be serviced properly, the clock movement must be removed from the case and the dial removed from the movement. Others will just open the side access panels and spray a silicone lubricate into the clock movement. This gets lubricate into places that should have no lubrication and will discolor the brass in the clock. Over time silicone lubricates get very thick and sticky and will stop the clock from operating. Expensive disassembly and cleaning are then require or a new movement must be purchased and the original scrapped. We do mail reminder cards to you every two years to remind you that it is time to have your clock serviced.