How to Repair a Cuckoo Clock. A cuckoo clock is a great novelty clock to have to your home. Many times you can repair them yourself. All it takes is an understanding of how they work and some patience. Try these repair tricks on any cuckoo clock that needs a tune-up.
Make sure the train-weight chain isn't hitting any obstruction before you take the cuckoo clock down from the wall for repairs. Look at adjacent pictures, sofa backs, chairs or any other furniture that may be preventing the clock from operating correctly.
Examine the case. Repair any obvious problems. Drill a slightly larger hole for the train-weight chain. Sometimes the wood in an older clock warps and causes the hole to catch the chain and mess up the way the cuckoo clock works.
Check to see if the cuckoo clock chain is on its sprocket. Tug gently on the train-weight chain. If it moves and you hear a clicking sound, the chain is on the sprocket.
Put the train-weight chain back on the sprocket, if you don't hear it clicking. Take the back off the cuckoo clock and loop the chain around the correct sprocket. Replace the back of the cuckoo clock.
Listen to the bellows. There are usually two-one for the cuck sound and one for the coo sound. If you don't hear sound as you press on the bellows with your finger, replace them.
Look at the night shutoff, if the cuckoo isn't working. Make sure it is properly set. Sometimes it gets caught half-way in between so the cuckoo doesn't work during the day or night.
Adjust the pendulum to make the clock run at the proper speed. Move the pendulum weight up if the time is too slow, down if it is too fast. It may take a while to set it properly.