How to Fix a Clock That Loses Time




Introduction: How to Fix a Clock That Loses Time

About: I am a high school engineering teacher (formerly an engine design engineer) and mother of two little makers who loves developing new projects - both personally and for my children and students to work through.…

The clock in my son's bedroom constantly lost time. Even with a fresh battery, it would run almost 10 minutes slow just a week after the battery was replaced. And while initially I thought this might be an ingenious trap by an 8-year old to get a few extra minutes of playing before bedtime, he seemed as surprised as me by the clock always being just a bit off.

This Instructable explains how we fixed our clock. It outlines two simple ways to clean and maintain your clock to ensure it keeps an accurate time without lagging.


  • A slow clock
  • Nail file or fine sandpaper or small file (for abrasive material removal)
  • Rag or paper towel or Q-tip (for cleaning)
  • Small adjustable wrench (optional)

Step 1: Cleaning the Battery Compartment

The most common cause of an analog clock losing time is that there is buildup in the battery compartment that is keeping the battery from connecting fully with the clock mechanism.

Remove the battery and check the leads to see if there is any buildup from a leaky battery, dust, etc.

Using a file (or other abrasive surface), gently rub the buildup away. If there is any remaining buildup that cannot be removed with the file, gently wipe it away with a damp rag. Make sure to let the leads fully dry before putting the battery back into the clock.

Step 2: Maintaining the Hand Mechanism

A clock that has been sitting in a dusty space - like a clock on the wall of a busy makerspace - can also lose time if there is any buildup in the hand mechanism.

To maintain your clock mechanism to avoid this problem, gently remove the hands as shown in the pictures above. Begin by removing the pin or threaded cap that holds the hands onto the axle. Next, carefully pull each hand off. If you plan to take the entire mechanism out, you will need to unscrew the small nut that holds the mechanism tightly to the clock face as well.

Once you have removed these parts, take a damp rag and wipe both the rotation axle components and the hands themselves. Once clean, reassemble (by working through the images in reverse order).

Step 3: Additional Troubleshooting

These two steps have successfully fixed two clocks in our home now and hopefully will keep your clocks running a little longer as well.

If neither of the two previous fixes works for your clock, you may need to replace the entire mechanism. These are relatively inexpensive and are easy to find at a hobby store or on Amazon.

If you have any other tips or tricks, please feel free to leave them in the comments. :)

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    8 months ago

    I have to try this!


    Reply 8 months ago

    Good luck! I hope it refreshes your clock and keeps it from losing those pesky minutes.

    John Harwood
    John Harwood

    8 months ago on Step 3

    I can't believe that dusting the hands or cleaning the battery contacts is going to fix the majority of slow-running clocks. You might need to go into the mechanism with a small paint-brush and remove any dust from the cogs. A dab of the lightest possible oil on the shaft ends may improve things but don't use WD40 or similar as that dries tacky and will slow the clock even more. If the cogs are white plastic than try some dry PTFE lubricant on them, very sparingly. As there is no escapement and the pendulum is there purely for show, there's no adjustment available on these cheap mechanisms. So if lubrication and cleaning doesn't sort the problem, that's the time to whang the clock movement. Be aware that there are several different sizes of drive shaft on these movements, and if the new doesn't match the old, you will need to buy new hands as well.


    Reply 8 months ago

    Thanks for the tips! While I have had success fixing slow clocks this way, I have also met with a few that- like you mentioned and like I discussed in the troubleshooting section - just need a new mechanism all together. :)