To remove a movement from the case, the crown with the winding stem often has to be removed after opening the case. In most cases this is quite simple, but there are also a few more complicated ways.
We take a look at some of them here, but without any guarantee of comprehensiveness.
Contents
- Screw or pusher close to the winding stem
- Quartz Movements
- No pusher visible?
- The case back cannot be opened?
- Negative Winding
Screw or pusher close to the winding stem
Let’s start with the simplest case. In this case, there is a screw or pusher near the winding stem onto which the crown is screwed (see picture above). They hold the so-called setting lever on the dial side and are therefore called setting lever screw and setting lever pin. The setting lever is marked1 in the following picture. It holds the winding stem at theTip of the green arrow. The setting lever spring is marked with2. It holds the setting lever securely in its two positions (crown pulled or pressed).
If you loosen the screw or press on the pusher with a suitable object, the winding stem including the crown can be pulled out.
The proper screw is usually the smallest one near the winding stem. It can be located to the left or right of the winding stem. Larger screws in the nearby area, on the other hand, usually hold a bridge of the movement.
Caution:
Only loosen the screw so far that the stem can just be pulled out. One or two turns of the screw are usually sufficient. It often helps to press the screw down slightly with the screwdriver when pulling. If you turn it too far, you will completely unscrew the setting lever on the dial side. This can only be corrected by removing the hands and the dial.
With many movements, it is also advantageous to pull the winding stem before releasing it, i.e. to bring it into the ‘hand setting’ position. Otherwise, parts of the winding mechanism may shift in such a way that they cannot be brought back into the correct position when the winding stem is re-inserted. Professionals refer to this as a displaced winding mechanism.
In this case too, the parts on the dial side must be realigned correctly by hand.
If a small screw is located exactly in line with the winding stem, i.e. neither to the left nor to the right of it, we are usually looking at an old pocket watch in which the hands are not set by pulling the crown, but by pressing a pusher on the case. A small lever can also be used instead of a pusher.
In this case, the movement does not have a setting lever, as this is only required if the crown has several positions. With these movements, the screw that holds the winding stem usually has to be unscrewed a little further. Sometimes it also has to be removed completely in order to remove the winding stem.
QuarTz Movements
For quartz movements, pushers are usually used instead of screws. Their position is often not in the immediate proximity of the winding stem. You can often find them by looking for an arrow on the movement that points to an opening, sometimes accompanied by the word Push. Here is an example of a Seiko/TMI VK63A at the positionmarked in red:
In some cases, the crown must be pulled out first so that the pusher appears in the corresponding position. For example, on a Miyota 8620A at the positionmarked in red here:
No pusher visible?
On some movements, e.g. from Seiko, no pusher is seen at first glance. It is there, but not visible. Only when the crown is pulled to the ‘hand setting’ position does it appear on the edge of the case next to the winding stem. The following picture shows this on a Seiko 7009A.
The case back cannot be opened?
It becomes even more difficult if the case back cannot be opened at all. I’m not talking about stuck case backs here, but about so-called monocoque or one-piece cases, in which the middle section and case back consist of a single part. There are two common ways of removing the winding stem.
One variant is the so-called split-stem crown. It consists of two parts and the part with the crown must be separated from the counterpart with a fairly strong pull on the crown.
This Junghans Olympic has a monocoque case and the movement, a Junghans 620.02 has a split-stem crown:
In the second variant, the glass must first be removed. Then there is a lever on the dial side near the winding stem that can be used to release it. Here is an example of a Mido 1147:
negative WInding
The negative winding system is mainly used in American pocket watches. Here, the winding stem is divided into two parts. A square with the crown is part of the case, the matching inner square is part of the movement.
The negative winding can usually be identified by the fact that there is no small screw near the winding stem!
There is no fixed connection between the crown and the movement. These movements therefore do not have a setting lever and can be removed from the case simply by pulling the movement out. If you are interested in the technical differences between the negative winding mechanism and the positive winding mechanism described above, you will find what you are looking for here: American Pocket Watch Movements