I have an Illinois thin watch with a cracked centre wheel jewel, the watch seams to be running well in all positions.
Would you fix or leave well alone.


Jim Carroll

Great question Jim:
I will be looking to see what the experts say.
If it were mine, I would leave it alone. In my mind, if the watch is dropped in future it may cause the jewel to fail; however even if you replaced it and should the watch be dropped, there is nothing stopping the new jewel from becoming damaged either. Seeing that the watch is a collectible and not used to time trains, I would say no, but hey, wadda I know!
gp

If you plan on running the watch you should replace the jewel. The cracks in the jewel will eventually wear the pivot. I've seen some examples in a text that showed the wear from a broken jewel.

The jewel is easy to replace, the pivot is not.

The cracked jewel will also effect the way that oil is distributed on the pivot surface. You have several options to replace the jewel.

It looks like it's bezel set. If that's the case the best option (i.e. "restore") is to find a bezel set jewel and replace in the same setting.

If you don't have a bezel set jewel and want to "repair" not "restore" you can either turn a new jewel setting and put in a friction jewel, or ream out the original setting and put in a friction jewel.

Jim,

Here is an interesting reply by Steve Maddox to a question about a damaged jewel.

Personally, I would clean the watch and make sure the cracked areas in the jewel are dirt-free. I would then remove and reclock the jewel assembly so the load bearing surface of the pivot is not against a cracked area. I would oil the jewel again midway into the next servicing.

David has described the proper course of action but the final determination is up to you.

Thanks for your comments on this subject, as this is a project I could tackle on my own, and the movements come up for spares or repair from time to time, so I will change it when I can get a similar Illinois part.

Jim Carroll

No way would I run the watch with such a crack. Even if it is clean, you still have a sharp edge made of one of the hardest materials (hardness 9 out of 10-diamond) cutting away at your pivot. As David said, replacing a jewel is trivial, replacing a pivot is not. What is the grade of the movement? A serial number would also help. Perhaps we can help you find a new jewel setting.

Don

Hi Don,
The Watch is an Illinois Marquis extra thin model 3; it is not an expensive watch. Serial No. 4184823. In the Illinois Material Catalogue 1923 the upper centre jewel is Order 5540. Factory No.1893.
As for your concern about me running the watch this is the first time I have wound the watch in well over a year, I have got myself another camera and I am updating photos on my watch page and had to look the watch out.

Jim Carroll