Elgin Grade 73

These are "before" images - before disassembly and cleaning. This is the dial side of an 18 size, stem-set Elgin movement. The large half circle is a screw head, or rather half of one, that holds a moving lever that is part of how the watch switches from winding to setting.

The special thing about this screw is that in order not to be loosened by the normal movement of the part under it, it has left-handed threads. The screw turns the opposite direction of normal screws to loosen and tighten. Many watch designs feature a left-handed screw someplace.

I often find left-handed screws in watches that are way over tightened by someone trying to remove them. And occasionally I also find a screw broken.

Here are more "before" images. This watch is pretty dirty, but I've seen worse. It has also had what looks like some normal machine oil applied. This sort of oil may as well be rubber cement in a watch.

As for the dirt though, I have seen many, many watches that "ran fine" but where loaded with particles of grit like this. These particles stick in the oil and form a powerful abrasive, wearing down moving parts. Until a watch that had no real trouble, stops with multiple parts now ruined.

If you have a watch that runs but has not been serviced, you don't have to get it serviced. But I strongly advise against running it. Running a watch without routine service is just like running a car without changing the oil.

Here are a few pictures showing the secondary serial number stamps on the various major structural parts of the movement. Notice again the 'n' like prefix for the millions (75). The movement's full serial number is 7557555.

Aside from being in severe need of basic cleaning, this watch was not running because the roller jewel is broken off. I also replaced the mainspring (not broken but really worn out), but I don't see any other issues.

Here is the replacement roller jewel (synthetic sapphire) and a few images of the balance assembly showing the 'D' shaped hole in the roller table where the jewel goes. The job is to heat the balance assembly in a warmer using an alcohol flame until it is hot enough to melt and flow shellac around the jewel to hold it upright.

I

This is the new roller jewel in place.

The balance wheel has this movement's serial number very faintly inscribed. It's hard to see. This is not all that common on older watches. balance wheels get swapped out over the years, probably to avoid changing the balance staff.

 Here is the dial side of this Elgin movement again. It's all cleaned and the broken setting lever screw, that left handed one, has been replaced.

You can also see the secondary serial number stamp on this base plate. It is prefixed with a sort of 'n' symbol.

Elgin's grade 73, 18 size, 7 jewels, made about 1899...