Seiko 7009 Movement Not Winding Up

The Seiko 7009 movement is an automatic watch movement which winds itself by the movement of the wrist. The way the Seiko 7009 movement winds itself is one of the oldest type of mechanism in this respect. If one of any of the components that are linked together to give the automatic winding result is broken or used up, it might be a possible cause why the movement is not winding up.

In this article, we will look into these auto-winding components and what to look for and fix to make the movement work again, assuming there is no problem with the balance wheel, the gear train and related components. At this stage I suppose you can already handle well the different watch repair tools. This is our movement in question:

seiko 7009

You should note that you can’t hand-wind this movement by its crown as you can usually do with other automatic movements. It can only be winded when the rotor is swung by the movement of the wrist. The rotor is the semi-circle shaped component on which you can see SEIKO TIME CORP 7009A engraved.

This part is the first thing we will look at, if ever our watch has stopped functioning. Many times, its screw, which you can see in the center of the movement gets loosened by shocks. So, if it is loose, we will tighten it. The wheel in the middle of the rotor may become unstable or tight, and thus, it does not swing correctly. In this case, you might need to replace it or put some refined oil in the ball bearings and turn it  several times until it become loose again (not the screw).

Now, suppose the rotor is fine, then we should move on to the next component. Take a look at the image below, whereby i have removed the rotor and also the balance wheel. Pay attention to the colored line I have drawn on it to make it easier to understand:

7009a-seiko-movement-5

The blue, green and red wheels work together to transmit the energy obtained from the swinging of the rotor to the mainspring, which is located just under the red wheel (the rachet wheel). Basically, the rotor will drive the blue wheel (first reduction wheel), which in turn will drive the green wheel (second reduction wheel), which in turn will drive the red wheel.

However, to store the energy, the red wheel is controlled by a bar, usually called the click, which transits underneath it (see the two red circles). The red circle near the green wheel shows a part from the bar in question which prevents the red wheel from turning anti-clockwise. Otherwise it will unleash all the energy stored in the mainspring. Hence, the bar or click allows the red wheel to turn clockwise only so that the energy can be stored. Thus we comprehend that if the tip of this bar is bent or broken, there will be nothing keeping the energy from escaping and being wasted. In this situation, we will need to straighten the bar again, but still, it is better to replace it.

Now that you know the mechanism well, you will understand that the problem may also arise from the first and second reduction wheels (blue and green wheels). However, I have never got any problem with the second reduction wheel (green wheel) except from watches in which water leaked into and made the wheel rust. Look at the blue wheel well, it has two hands that are linked to the green wheel, they are called the pawl levers. The tips of the two hands sometimes get used and are unable to drive the reduction wheel and thus do not transmit the energy to the mainspring.

So how would you expect your watch to function if it doesn’t have any energy? The solution is to replace this part but it might be difficult for beginners to replace this part. You will need remove the plate completely (see image below) to be able to replace the part.

7009a-seiko-movement-3

What about Seiko movements other than the Seiko 7009?

Many other automatic Seiko movements (e.g 7s26) functions in a similar manner and hence the same troubleshoots will apply to them.

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