Spotting problems with watch movements

A while back I was asked to help with understanding what to look for when viewing a potential purchase, and using movement photos as your only guide. In this post I’ll explain a few things that I look for when considering if a movement is in good shape.

Note that this is only a guide, and without having the watch in hand and inspecting it under a microscope (along with other tests on a timing machine) it is quite difficult to say with 100% certainty what the condition of a movement really is. In fact, when I get a watch in for service, I let the owner know that only after fully disassembling the movement, looking for evidence of wear, and then cleaning and inspecting each parts under the microscope will I know for sure what may need replacing.

In addition, each situation is different so in fact if “the price is right” then even badly damaged movements inside watches may still not be a factor in determining if you buy it or not. For example if you are after a case or case parts, and the movement is completely rusted, it may make sense to buy the watch anyway if the price is right.

So here are some things to look for when viewing movement photos in an auction or sale:

Signs of obvious damage like rust - it doesn’t take much insight to understand that this Seamaster Chronograph watch has some serious problems:



Now rust can be much more subtle than the above example of course, so if you see anything rust coloured, take note. Rust that has been cleaned up will tend to look like black spots or dark stains on the steel parts.

Some other obvious issues would be things like fingerprints where they should not be, as on this IWC (that had been serviced by the brand service center, believe it or not!):



Sometimes things are more subtle, like a part that doesn’t match the quality of the remainder of the movement. In this IWC pocket watch (one of those conversions made into a wrist watch) the movement was finely finished, but the balance wheel looked very crude - some close shots to show what I mean:





Now here is what a genuine IWC balance I had to find for this watch should look like (the new balance complete was certainly not inexpensive):



If you see debris in the movement, then that is usually not a good sign - I admit this was only really visible after removing the automatic winding, but I use this example to show that when there is debris, it has to come from somewhere:



And in this case most of it came from the crown wheel wearing the barrel bridge:



And some from the winding pinion wearing the main plate and barrel bridge:



On vintage Omega calibers like the 55X, 56X, and 75X series movements, one of the first things I look for is a worn rotor pinion, or the effects of it anyway. Here is a Cal. 751 - note the red arrow points to a bright ring at the outer edge of the movement:



You can also look at any photo of the inside of the case back for signs that the rotor has been scraping on the case back:



If the photo is good enough, then you can also look for signs of wear on the rotor itself:



Now this worn pinion is not a big thing to repair itself, but I find often that watches that have had time to develop these wear signs have often been running for a long time without service. So this is usually a pretty solid predictor that other parts in the movement are worn. For example this particular watch needed all the wheels in the automatic winding replaced, plus several train wheels - the costs add up fast on these calibers.

Of course this problem is not limited to vintage movements, and modern movements also have worn rotor bearings:



You can see the tell tale ring on the inside of the inner cover:



And wear on the Côtes de Genève can be pretty easy to spot, as it tends to take the high spots off:



Another thing to look out for are chewed up screw heads - this can be a sign that the servicing that has been done to the watch is not necessarily up to par. I can say unfortunately that I see a lot of damage inflicted on movements by people who have worked on them in the past. Some of the best vintage movements I have ever serviced are those that haven’t been touched for decades - the watch was worn until it stopped, and then tossed in a drawer and never serviced.

If you can see the balance area well enough, look for possible problems with the balance spring like this one:



Now I’m sure all balance spring problems will not be this obvious, but really it is only obvious damage you are looking for (or rust) because most minor problems can be sorted out at service.

So these are just a few things that I have put together - I’m sure there are others that would be red flags, such as screw heads obviously broken off, missing parts, etc. but hopefully this will give you a start when looking at your potential purchases.

Of course if you have any questions, please post them and I’ll do my best to answer. Hope this is helpful.

Cheers, Al

another brilliantly practical post. Much obliged, Al.

another great post by @Archer , btw,...would you consider moving to my neighborhood? I'll provide some steady work opportunities! 😉

I know this from very first hand! 😉

Al, got any shots of hour wheels missing teeth, I've see that a time or two. In fact I've seen watches supposed serviced come back with wheels missing teeth.

Added to my favorite list, thank you.

Al has a watch of mine that the movement has not been seen by me and glad I didn't see it in the above 😉

Great post Al , that IWC balance 😲

Glad you all found this useful...now to some questions...


The hour wheel is under the dial, so not something that really falls into the subject at hand (spotting issues using movement shots in sales) but it's not common to have broken hour wheel teeth in my experience. There's usually very little load on the hour wheel, so if it has broken teeth, it's often from mishandling of parts during assembly or something (I'm sure there are instances where it can get damaged in use though).

If you are going to spot broken teeth from the movement side, they would have to be pretty obvious wheels. Although this photo is taken with the automatic winding system removed from this SW200, with that system mounted you could still see the ratchet wheel and if the broken teeth were in the right spot they could be visible:



But broken teeth are not all that common in the watches I service. With some older vintage pocket watch designs, if the mainspring broke (or when the mainspring broke I should say) they often suffered broken teeth due to the design as the shock would get translated to the wheel train. To combat this some makers had safety pinions that were screwed together and would unscrew in the event of a broken spring.


Your watch was in pretty good shape...nothing major. 😀


No I didn't forget, just needed some time to do this. I do have to take a few minutes out of my day posting here to actually service/repair some watches from time to time. The pay here for being a consultant just doesn't cut it I'm afraid. 😉


Not really. All movements have weak spots in them, some have more weak spots than others, but the main reason for "worn out" movements is just pure and simple lack of service. In some cases it's bad service, but mostly lack of service.

Now clearly there are some general things to keep in mind, such as:

- The older the movement the more likely it will have worn parts.
- A movement in a well sealed case will generally fare better than one in a not very well sealed case.
- The fewer moving parts, the less likely expensive repairs will be needed - for example an automatic winding watch will generally have more worn parts, because first there are just more parts in the movement, and the automatic winding parts are in motion quite a lot with fairly large forces (in the watch world anyway).

Cheers, Al