How to Replace a Clock Gong Coil

The deep, resonant sound of a striking clock depends heavily on a properly functioning gong coil. When a clock’s hour or half-hour strike becomes weak, tinny, or disappears entirely, the gong coil may be loose, cracked, or improperly aligned. Learning how to replace a clock gong coil helps you restore the rich, classic chime your clock was built to produce.

Step 1: Understand the Gong Coil’s Function

A gong coil is a coiled metal wire, usually mounted to a metal base, that resonates when struck by a hammer connected to the clock’s strike train. Gong coils vary in size, tone, and mounting style, and they’re typically found in:

• Mantel/Wall clocks
• Some floor clocks (in place of chime rods)

Unlike bell-style or rod chimes, a gong coil gives off a singular, sonorous note that echoes deeply after each strike.

Step 2: Identify a Damaged or Worn Gong Coil

You may need to replace the gong coil if:

• The chime sounds muted, tinny, or dull
• You hear buzzing or rattling during strikes
• The coil is loose, cracked, or bent out of shape
• The gong mounting bracket is corroded, warped, or detached
• The hammer doesn’t strike the coil cleanly

If the hammer still moves normally, but the sound is off—or absent altogether—the gong coil is likely the issue.

Step 3: Select the Right Replacement Gong

Gong coils vary in:

• Coil size (number of windings and diameter)
• Mounting plate type (L-bracket, flat base, or upright post)
• Strike pitch (higher for smaller clocks, deeper for larger ones)

Match the replacement as closely as possible to your original part. If you’re unsure, measure:

• The diameter of the coil
• The spacing of the mounting holes
• The height of the mounting bracket

Clockworks offers a variety of gong coils suited for different styles and time periods.

Step 4: Gather Tools for Removal and Replacement

You’ll need:

• Flathead screwdriver or drill (depending on screw type)
• Needle-nose pliers
• Small wrench (if nuts are used on mounting bolts)
• Clean cloth to protect the case interior
• Small hammer (for minor alignment adjustments)

Clear a padded surface to work on, and remove the movement if needed for access.

Step 5: Remove the Old Gong Coil

1. Open the clock case from the back.
2. Remove or move the movement (only if the gong is blocked).
3. Locate the mounting screws or bolts holding the gong bracket in place.
4. Unscrew carefully, keeping any washers or hardware in a labeled container.
5. Gently lift out the gong coil and base.

Avoid bending the coil or pulling the wires—it’s best to remove it as a complete unit with the mounting plate.

Step 6: Install the New Gong Coil

1. Position the new gong base in the same orientation and location as the original.
2. Use the original screws or supplied hardware to secure it snugly.
3. Make sure the coil does not touch the case wall, movement, or other parts.
4. Align the strike hammer with the flat portion of the coil. The hammer should just graze the coil—not hit it forcefully.
5. Use your fingers or needle-nose pliers to bend the hammer arm slightly if needed for proper distance and angle.

Strike sound should be clear, deep, and resonant, with minimal bounce or echo.

Step 7: Test the Strike Sound

Once installed:

1. Slowly move the minute hand forward until the clock reaches the hour or half-hour.
2. Listen carefully to the chime.
3. Confirm the hammer hits the gong in a clean motion and retracts immediately.
4. If the sound is too soft, the hammer may be too far away.
5. If the sound buzzes or clanks, the hammer may strike too hard or at an odd angle.

Fine-tune the position until the strike is strong but smooth.

Step 8: Maintain the Gong and Hammer

To keep your clock sounding great:

• Avoid oiling the hammer or coil—these parts should stay dry
• Keep the interior free from dust
• Gently tighten mounting screws every few years to prevent vibration
• If the hammer sticks, clean its pivot point without lubricants

If the hammer mechanism ever binds or fails to retract, service the strike train separately.

Common Mistakes to Avoid

Over-tightening the gong base — May warp the bracket or distort the sound

Misaligning the hammer — Causes double strikes, clanks, or no sound

Installing the coil too close to the case wall — Prevents proper resonance

Using the wrong size gong — Produces a weak or mismatched tone

Oiling the hammer — Causes sticking and softens the strike

Summary

Replacing a damaged gong coil restores the deep, clear strike tone that defines a quality mechanical clock. By choosing the right size, aligning the hammer correctly, and avoiding over-tightening, you can return your clock’s chime to its former beauty. Keep the coil clean, leave it dry, and adjust only with gentle pressure. For reliable replacement gong coils and support, visit Clockworks.com or email clockworks@clockworks.com—we’re here to help your clock sound as good as it looks.

Updated on: 28/09/2025