Why Clocks Need Cleaning Every 5–10 Years

Mechanical clocks are remarkable machines—capable of running continuously for decades—but only when properly maintained. Even if a clock appears to run “just fine,” its internal components may be experiencing gradual wear that isn't immediately visible. Inside every mechanical clock, oil plays a crucial role in reducing friction between the brass plates and steel pivots. However, this oil slowly dries out, absorbs dust, thickens, and eventually transforms into an abrasive compound.
For this reason, professional cleaning every 5–10 years is essential to keep a clock healthy, reliable, and capable of performing as it was designed. This guide explains what happens to clock lubrication over time, how dirty oil accelerates wear, and why routine servicing is one of the most important aspects of mechanical clock ownership.

What Happens When Clock Oil Ages?

Clock oil is formulated to last many years, but it does not remain stable forever. As it ages, it undergoes several chemical and mechanical changes:

• Evaporation slowly removes lighter components of the oil

• Thickening occurs as remaining oil becomes more viscous

• Oxidation darkens the oil and reduces its lubricating strength

• Dust attraction increases as oil turns sticky

• Sludge formation occurs when old oil mixes with airborne contaminants

This transformation is unavoidable. Even in a clean home, microscopic dust enters the case and combines with aging oil. Over time, this sludge behaves like fine sandpaper, increasing friction throughout the gear train and creating conditions that dramatically accelerate wear.

Wear Caused by Dirty Movements

Once oil begins to degrade, the mechanical consequences compound quickly. Dirty movements commonly suffer from:

• Oval pivot holes, caused by repeated wear as pivots grind into brass

• Escapement wear, altering the delicate geometry that keeps the clock in beat

• Reduced pendulum amplitude, which makes the clock more sensitive to leveling error

• Chime and strike failures, where hammers become sluggish or inconsistent

• Random stopping, especially in older or partially worn movements

The alarming truth is that wear accelerates exponentially once oil breaks down. A clock that has been running for years without service may be experiencing damage much faster than a new owner realizes. By the time symptoms appear—slowing, stopping, or irregular chiming—some wear may already be significant.

The Professional Cleaning Process

A proper clock service is much more than simply adding oil. In fact, applying new oil to a dirty movement only traps contaminants and increases wear. Instead, professional servicing involves a complete overhaul that restores the mechanism to near-original condition. The process typically includes:

• Full disassembly of the movement

• Ultrasonic cleaning of all brass plates, gears, arbors, and pivots

• Rinse and drying cycle to remove all remaining residues

• Pivot polishing, ensuring smooth rotation and optimal lubrication retention

• Bushing installation where pivot holes have worn oval

• Careful reassembly of all components

• Application of fresh, specialized clock oil at each pivot

• Beat and timing adjustment to ensure accurate operation

This thorough process removes decades of accumulated debris and restores the proper mechanical relationship between gears, pivots, and plates. When completed correctly, the clock will run more efficiently, more quietly, and far more accurately.

How Often Should Cleaning Occur?

Most mechanical clocks require cleaning every 5–10 years, though the exact interval depends on several factors:

• Climate — Humid environments accelerate corrosion and oil breakdown

• Case type — Open or lightly sealed cases allow more dust to enter

• Dust exposure — Homes near roads, farms, or construction zones introduce more debris

• Movement design — Some movements run hotter or at higher loads and require more frequent attention

Weight-driven clocks, such as grandfather clocks or cuckoo clocks, often need servicing on the earlier end of the range. Their heavier trains apply greater force on the pivots, meaning dirty oil can cause wear more quickly than in smaller spring-driven movements.

Benefits of Regular Cleaning

Routine professional cleaning offers several long-term advantages:

• Prevents costly repairs by stopping wear before it becomes severe

• Improves timekeeping by restoring smooth power flow

• Restores power transmission, allowing the escapement and pendulum to function at full efficiency

• Protects antique value, preserving original components and craftsmanship

• Extends lifespan by decades, helping heirloom clocks last through future generations

A well-maintained movement can run beautifully for many years with only minimal adjustments. Neglected clocks, on the other hand, often require extensive (and expensive) restoration.

If you're in Calhoun, GA, Time and Seasons Clock Repair provides complete cleaning, restoration, and professional maintenance services for antique and modern clocks.