Slow Clock Question

I have a neato clock that my grandmother gave me. It’s a real gravity/pendulum clock with gears and stuff. (Remember those?) When I came home a few weeks ago, it had stopped running. The weight would just hang there but it wouldn’t run. I finally got around to taking it apart to see if I could find out what’s wrong. It seemed to me that the part where the pendulum connects to the gear (which turns one tooth per swing of the pendulum) was getting stuck. So I sprayed some WD-40 on it and voila! A working clock!


When I started the clock and set it last night before I went to bed (admittedy, still half-drunk from the evening’s festivities, it was on time and running perfectly. When I woke up, it was still running but it was had lost 20 minutes, and was not 20 minutes behind.

What could cause such a travesty? I thought maybe I put too much WD-40 on, but I didn’t put that much, really. Any ideas on what could be wrong and how to fix it?


When I woke up, it was still running but had lost 20 minutes, and was now 20 minutes behind.

Personally, I would think that the pendulum acts as a governor and lubing the gears shouldn’t change the speed of the clock. It looks like I’m wrong though…

Can you shorten the pendulum? On our clock, there’s a nut under the weight (it looks like a spike.) A shorter pendulum will swing faster, causing the clock to run faster.

If it is a nicely built clock it should be professionally adjusted and lubricated. Spraying WD40 on the clock may solve the immediate problem but it is probably not the best solution as the solvents in WD40 may have a negative impact on other parts of the clock and do not provide optimum lubrication.

What Astro said!

What Friedo said!

Well it’s now about four hours since a re-set the clock, and it’s already lost ten minutes again.

I checked the pendulum, and it can’t be shortened.

My guess is that something inside must be slipping. One of the gears is not catching once in a while, leading to the lost time. I’ll take another look at it tonight. I’m beginning to think the WD-40 may have hurt it. :frowning:

Most pendulum clocks will have what is known as a rating nut. It usually indicates a plus and minus direction. Plus will speed the clock by slightly shortening the pendulum. They can be on the face, above 12 or on the bottom.

Thanks, Ned, I’ll take a look and see if this has one.

Point your browser to your favorite search engine and search
for web sites about clock repair.

Problem is, it’s gotten somewhat difficult to find dedicated clock repair people in this digital age. Thankfully there are still folks out there who do but don’t expect overnight service. There are several web sites maintained by licensed clock repair people “Horologists” ?

One web site I visited mentioned “3 in 1” Oil as a serviceable substitute for the (very!) expensive clock oil used by repairmen. I’ve also resuscitated older, inexpensive clocks with solvents (like WD-40) followed by a very light oiling with “3 in 1” but this is not recommended practice and is certainly not the way to take care of heirloom products, collectibles, historical timepieces, etc.

A dedicated clock repair business should be able to help you…

Wd40 is NOT oil. You can get Clock oil as the person said.

Also, you didn’t tell us what type of Clock it is. You know who made it? When?