A non-working pendulum is one of the most common issues faced by grandfather clock owners—and also one of the most misunderstood. When your grandfather clock's pendulum suddenly stops swinging, it doesn’t always mean major damage. In fact, most causes are simple to diagnose and fix—if you know what to look for.

1. Improper Leveling

A grandfather clock must be perfectly level to operate correctly. If the case is leaning slightly forward, backward, or side to side, the pendulum may lose its rhythm and stop.

Fix:
Use a spirit level to check the base and sides of the clock. Most clocks have adjustable feet or shims that can help you level the case properly.

2. Pendulum Interference

Sometimes, decorative parts or loose components interfere with the pendulum’s swing. A slight touch from a chime rod or case lining can be enough to stop it.

Fix:
Open the case and observe the pendulum swing. Make sure nothing is brushing against it. Also, verify that the pendulum isn’t hung too high or low on the leader.

3. Worn Suspension Spring

The suspension spring holds the pendulum and allows it to swing freely. Over time, this thin piece of metal can wear out, bend, or break.

Fix:
Inspect the suspension spring above the pendulum. If it looks twisted, cracked, or bent, replace it with a compatible spring (available from most clock parts suppliers).

4. Overwound Movement or Weight Issues

Contrary to myth, clocks can’t be "overwound," but if a clock has been wound improperly or the weights are tangled, the gears may not engage correctly—causing the pendulum to stop.

Fix:
Check that all weights are moving freely and evenly. Make sure cables or chains aren't jammed, tangled, or sitting off-track.

5. Dirty or Dry Movement

Over time, dust, old oil, and grime can build up inside the clock’s movement, preventing the escapement mechanism from operating smoothly.

Fix:
A proper cleaning and oiling by a professional clock technician is often required. Never use household oil—it can damage the brass components.

When to Call a Professional

If your grandfather clock pendulum still stops after basic adjustments, it's time for expert help. Avoid DIY repairs on internal mechanisms unless you have clockmaking experience. A licensed horologist can inspect, clean, and calibrate your clock without damaging delicate parts.

Preserve the Legacy of Your Clock

A stopped pendulum doesn’t mean the end of your clock’s life. It’s usually a sign that your timepiece needs a little attention. Whether your grandfather clock is a new addition or a family heirloom, regular maintenance and timely repairs can keep it ticking for generations to come.