The Keyless Works in a watch is what controls the manual winding, quick date changing and time setting functions of a watch. Back in the old days pocket watches had to be wound by a “key”. The advancement of winding a watch by the stem and crown made the watch ‘Keyless”, hence the name.

So what is the Keyless Works in the ST36?

Well, basically the Keyless Works controls the functions of the watch. It is what allows the watch to be wound, and it is what starts the process of the time setting for the watch.

The Movement has two sides.

Dial Side

The dial side of a ST36 Movement
The dial side of a ST36 Movement

The dial side is just like it sounds; it has the dial on it. under it are the keyless works, the motion works and the Calander system if the movement has one.

Watchmakers Side

The watchmakers side of a ST36 Movement
The watchmakers side of a ST36 Movement

The other side of the watch is what we refer to as the watchmaker side. This is where the power train, and balance wheel are.

Releasing the Stem

The first part we need to talk about is the setting lever screw. The setting lever screw on this particular movement is unscrewed instead of a push button to release the stem.

When you’re working on a movement like this, if you’re just trying to take the stem out, you want to be careful when turning the release screw so that you don’t unscrew it so much that it comes out of the setting lever. If it does, then you’ll have to disassemble the entire keyless works to be able to reinstall it.

Setting Lever Screw

This is the setting lever screw. To release the stem, all you want to do is turn it one quarter turn at a time while pulling on the stem until the stem is released.

To put the stem back in, you merely push it in. Sometimes you have to turn it a little bit to get it to go in because the stem is square and the hole its going in is also square. Then you just re-tighten the screw, and the stem is locked back in position.

Parts of the Keyless Works

The Click

The Click
The Click

The Click engages with the teeth of the Crown wheel allowing it to turn when winding the movement but prevents it from reversing and allowing the mainspring to unwind.

The Click Spring

click spring
The Click Spring

The Click Spring keeps the Click under tension.

The Ratchet Wheel

The Ratchet wheel
The Ratchet Wheel

The ratchet wheel has a square hole in the center that fit over the square end of the barrel arbor. The ratchet wheel is turned by the winding pinion.

The Crown Wheel

The Crown Wheel
The Crown Wheel

The Crown wheel is turned by the winding pinion and turns the Ratchet Wheel.

What is unique about this wheel is that the screw has a reverse thread on it. Normally you would turn a screw to the left to loosen it and to the right to tighten it. This screw is just the opposite. Sometimes the screw will be marked with additional lines on it, letting you know that it is a reverse thread, but it usually is not like that.

One of the biggest mistakes people make removing this is breaking it off, and that is not something you want to do. The other thing I would point out on this wheel is that it has an inner ring, and if you’re not careful, that part will get lost because you won’t even realize it’s there.

Crown Wheel Ring

The Crown Wheel Ring
The Crown Wheel Ring

The crown wheel ring fits on the post and the crown wheel sits around it. Be careful with this part as it is not easy to see, and you will lose it if you are not aware that it’s there.

The Winding Pinion

The Winding Pinion
The Winding Pinion

The Winding Pinion is turned by the sliding pinion and engages with the ratchet wheel on the opposite side of the movement. It actually will spin freely on the stem and is only able to turn the ratchet wheel when the sliding pinion is engaged with it. The winding pinion is made from two different types of teeth. The first set are on the outside and engage with the ratchet wheel. The second set are ratchet teeth and engage with the sliding pinion.

The Sliding Pinion

The Sliding Pinion
The Sliding Pinion

The Sliding Pinion has a square hole in it and slides back and forth on the square part of the stem. When the stem is turned it cause the sliding pinion to turn with it. The sliding pinion has two styles of teeth on it. The first are ratchet teeth that engage with the ratchet teeth of the winding pinion. The second teeth, on the other end engage with the setting wheel on the motion works which changes the time.

The Setting Lever

 The Setting Lever on a ST36 Movement
The Setting Lever

The Setting Lever has 2 jobs. The first is to lock the stem into the movement so it doesn’t come out. It does this with a small pin that locks into groove on the stem. The setting lever is held in place by the setting lever screw. When you turn the setting lever screw, it allows the pin on the setting lever to come out of the groove in the stem enabling the stem to be pulled out.

The second job of the setting lever is to push the yoke. Then the stem is pulled out to the 2nd position, the same pin on the setting lever that locks the stem into the movement, pivots the setting lever which pushed the yoke.

The Yoke

The Yoke on a St36 Movement
The Yoke

The Yoke pivots on one end and sits in the grove of the sliding pinion on its other end. Its job is to control the position of the sliding pinion. When the stem is in the 1st position, it is the yoke that keeps the sliding pinion tight to the winding pinion so the watch will wind.

When the stem is pulled to the 2nd position the setting lever forces the yoke to move the sliding pinion away from the winding pinion into the time setting position.

The Yoke Spring

The Yoke Spring on a ST36 Movement
The Yoke Spring

The Yoke Spring keeps tension on the yoke which keeps the sliding pinion tight to the winding pinion when the stem is in the 1st position.

The Setting Lever Spring

The Setting Lever Jumper on a St36 Movement
The Setting Lever Jumper

The Setting Lever Spring has two jobs. The first is to secure the yoke and yoke spring in their positions.

It’s second job is to keep the setting lever in its correct position. The end of the setting lever spring has two notches in it. These notches engage with a pin on top of the setting lever. These notches hold the setting lever in the correct position when then the stem is pulled in and out.