Basic watchmaking tips - Spotting wear

This is another installment in a series of watchmaking tips – previous threads can be found here:

https://omegaforums.net/threads/basic-watchmaking-tips-cleaning.56365/#post-696021

https://omegaforums.net/threads/basic-watchmaking-tips-oiling-part-1.62310/

https://omegaforums.net/threads/basic-watchmaking-tips-oiling-part-2-the-mainspring-barrel.71246/

In this post I wanted to cover a topic that might seem obvious, but it isn’t always, and that is spotting wear and other anomalies during a service. Any proper full service should include a full inspection of all parts for wear or other damage, and where appropriate repair or replacement of those parts. Failing to do so is not doing the job properly. Note that Omega does spell out what is acceptable or not in their working instructions in terms of wear.

One thing that takes some experience is “training your eyes” to see things when you aren’t really looking for them necessarily. The instructor I had always told the class that when you are working on a movement, if you see a flash of shine coming off the movement that looks out of the ordinary, you need to stop and take a look. The same can be said for areas that might be darker than their surroundings – you are looking for inconsistencies.

I advocate getting a microscope, and even if it’s not one that has enough focal distance to actually do any work under, one that you can use to simply inspect the condition of parts with is a very valuable tool. In my view even a 10X loupe is not sufficient to be certain what you are seeing when you are inspecting parts for wear.

This process is very similar to what I used to do when I was working as an engineer and in charge of rebuilding industrial machinery used for manufacturing goods. Full disassembly, cleaning, parts inspection, and every part we looked at was given one of three results...Repair, Replace, or Reuse.

So the first thing I look for when I open up a watch is any debris that is out of the ordinary. If you open up a watch and see fine metallic dust all over the movement, you know most likely something is wearing out inside:





In this case you can see the round post is nearly 1/2 gone from wear:



In this case not only can we see some products of wear in the jewel, but the pivot is way off center, so it’s clearly going to be worn out:



After cleaning I always inspect the pivots of every wheel under the microscope, and also look at the pinion leaves for wear or corrosion. Worn, scored, or rusty parts are easily spotted using a microscope – some examples below.

Worn pinion leaves:



Worn pivot:



This one worn on both sides:



Worn bushing:



I also inspect jewels for defects – cracks, chips, and even though you may not think it’s possible, jewels can wear also. If you see anything that looks off, like a jagged edge, then take a closer look and don’t let it go – chipped pallet fork jewels:





Wear can be more difficult to spot in some cases, but a divot worn in a cap jewel is more common than you might imagine. Often you have to tip the jewel at an angle to get a reflection across the surface in order to see the wear:



Another one:



And another one:



The most common cap jewel to have this wear is the one that the balance staff is riding on when the watch is dial up (so the top jewel in the balance bridge). Once oils dry out here, it’s like having a small drill bit drilling away at the surface of the jewel, and this can also flatten the end of the pivot. Both of these things can cause loss of balance amplitude, so a difference in dial up and dial down amplitude can be an indicator of this wear.

Less common but still possible is a worn pallet fork jewel:



A severe example here:



Note that some wear you don’t always see directly, but only see the effects of it on other parts. For example you may not see that the bearing in this rotor is worn directly by looking at the bearing race or balls, but you can certainly see that the rotor has been rubbing on the inside of the case back or inner cover:



You can also see the wear on the high spots of the rotor:



Closer look:



So another example of looking for indirect wear is a common one on vintage Speedmaster movements, a worn barrel arbor hole. When I remove the main wheel train and barrel bridge, I look for wear marks on the underside of bridge made by the ratchet wheel:



You can see corresponding marks on the ratchet wheel itself:



Now this wear itself is not a problem, but the cause of it is. The reason this wear is there is due to the hole in the bridge that the barrel arbor goes through is worn. The arbor does not go all the way through the bridge, so you can see the extent of the wear here easily by the step that is formed inside the hole:



The wear in this hole allows the mainspring barrel to tip inside the movement under load, and it causes extra wear on the underside of the bridge, but also can cause extra drag in the movement. Instead of replacing the entire bridge for several hundred dollars, these can be repaired with a bushing:



One area I always look for wear is on the main plate and bridges where the winding pinion rides. This is a spot that rarely calls for any lubrication in a tech guide, but I always put some there if there is contact in this location. Here is one that is worn heavily from the winding pinion running against the main plate in this area:







The barrel bridge was also worn:



There are also areas not subject to a lot of rotation that can wear or get damaged, like teeth on ratchet wheels:



This is a worn hammer from a chronograph:



Worn teeth on winding and sliding pinions:





So careful inspection of parts during a service is a critical item. Putting back worn parts is certainly going to lead to a cheaper service, but it's not doing the job properly.

As always if you have questions, please let me know and I’ll do my best to answer.

Cheers, Al

Thanks @Archer for another great thread.

This is why I try to never quote a price to any newbie what a service may be as you never know until you dismantle the movement what a proper service with parts will cost.

Those micrographs do a great job of illustrating exactly what you’re referring to. Many thanks for this tutorial.

Very educational. Thank you for taking the time to post this.

Great information and fantastic photos. I like the advice about the winding pinion, it reminds me of my dad (a GM master mechanic), he told me when I was little that any metal on metal contact should be lubricated, it is a rule I have always followed for anything I take apart.

Archer, just out of curiosity. When you give a watch a service, do you examine every part for wear? That must be very time consuming.

Yes, I do the job properly. Once it becomes part of your routine, it actually doesn't take a huge amount of time.

Wonderful pictures.

I don't think you need to stop using the watch, but stepping up on the maintenance to preserve the parts that are inside the watch is a good idea.

This is why the answer I give when someone asks me how often to service a watch is "it depends" because there's no one strategy that is appropriate for all situations. A modern watch with readily available parts can be run into the ground with possibly only minimal added expense at service time, but the same can't be said for a vintage watch where the parts are long discontinued, difficult to find, and expensive when you do find them.

Cheers, Al

Thank yyou