Expert: Michael Radi - 2/4/2011

Question
My movement is a Kieninger sks12 116 cm. My problem is the center chain will not stay up it just falls right to the floor. Can i repair this or do i have to replace the whole movement. If it is repairable, can you tell me where to get the parts?

Answer
The problem is in the chain gear. This is the large wheel and sprocket that the chain rides over. There is a system on that gear that should allow the chain to only move in one direction. The important parts of this system are the click gear, the click (small paw that drops into teeth of a gear within the chain gear) and the click spring (flat spring that presses down on the click so the click seats firmly between the teeth of the click wheel).
The most common failure in this system is the click spring, It may be broken. If you are lucky the click simply snapped back and went under the click spring. If this is the problem you can push the click back into place and everything will most likely be fine.
Sometimes the click or teeth of the click gear become damaged. This is a bigger job and it's usually easier to replace the entire chain gear than repair it.
The whole issue here is accessibility of the chain gear and the parts inside it. Usually the chain gear has to be removed from the movement for repair. A good clock repair person can pull this gear out of the movement without disturbing the other gears in the clock. I don't suggest that a person with no clock experience try doing this. It's very possible that all of the gears will fall out of the movement because the plates have to be spread apart to get that gear out.
I think your only hope of repairing this yourself would be if the click is set back under the click spring. See if you can visually locate the click and click spring. Let me know if I can help you further.
Michael