Girard Perregaux – Cal. AS 1203

Hi,

this is the first of hopefully many watches that we will be buying, servicing and then selling. This particular watch needed a whole lot of love. Such a great looking woman’s Girard Perregaux watch though, so, this just couldn’t be passed up.

With the case back off, we can see a very clean A. Schild movement.

Just to have some point of comparison of a before and after the watch is overhauled, here’s a shot of it on the timegrapher. You can see that this watch is gaining 108 seconds per day. The amplitude isn’t that bad for a watch that was made in the early 50’s, but, will improve after a cleaning and changing the mainspring. Also, that beat error isn’t looking great, so, I’ll fix that up too. If you’re thinking to yourself, what is the amplitude, beat error and rate.
The rate is how much the watch is gaining or losing per day, and that is in seconds. In this case, 108 Seconds, or one and a half minutes.
In electronics, the amplitude can be thought of as a rate that goes up and down. For example, a AC amplitude is the curve that when at the top is the rate of that amplitude as well as when it reaches the bottom. So, for a watch, think of a balance wheel that turns on its axis as the amplitude. In this particular case, the amplitude (see pic) is 243 degrees. If you take anything that is round, and give it a full 100% turn, then that is 360 degrees. A healthy, newer watch should have an amplitude of 270-320 degrees. An older watch like this one can be anywhere between 250-310 degrees. So, 243 really isn’t that bad at all considering it will improve.
Lastly, the beat error is the difference in milliseconds from one full turn of the balance wheel in one direction compared to one full turn in the opposite direction. So, the difference between it going clockwise to anti-clockwise.

This case has seen much better days 🙁 That’s not a problem, we’ll get the case re-plated.

With the movement out and hands taken off, it’s time to get to work!

I start off with removing the cannon pinion and the rest of the motion and keyless works.

After that is done, time to turn the movement over and remove the balance for safety sakes, and then remove the crown and ratchet wheels.

Next, I start removing the gear train.

The last step is to remove the mainspring barrel.

Now, that all the parts have been cleaned, it’s time to start re-assembling the movement. I’ll start off with replacing the mainspring. Although the amplitude wasn’t that horrible in the above photo, it’s generally a good idea to change out the old mainspring and replace it with a new one.

I start off with adding the barrel to the mainplate and then attaching the barrel bridge.

Followed by gear train.

Next, it’s time to replace the click and click spring, followed by the ratchet and crown wheels.

Then, it’s time to turn the movement over and oil all the pivots.

It’s time to install the canon pinion back, followed by the keyless and motion works.

After that, it’s time to yet again turn the movement over and install the pallets, followed by installing the balance wheel. Ahhhh, look how nicely that balance wheel is turning. It was eager to get back to work 🙂

Time to put it on the timegrapher and regulate the movement finally. I’m not happy with the beat error whatsoever.

Most watches have a regulator attached to the balance so you can fix both the rate and beat error. This movement however, doesn’t. The only way of properly adjusting this type of movement is to remove the balance (which, I apologize for not taking any pictures of) from the balance bridge. Then, turning the collet on the underside of the balance either clockwise or anti-clockwise. You do not, however, know which direction to turn it. The beat error doesn’t say negative or positive number, just a decimal. In this case, I was extremely lucky, I turned it anti-clockwise, perhaps a half of a degree. So, I was actually lucky both ways, I turned it the right direction and the right amount. How’s that for skill 🙂
Generally, in life, a flat-line is a bad thing, but, in regulating watches case, it’s a good thing 🙂

A quick shot of the movement with the dial back on, case and case ring with a new crystal. But, more importantly, look at the lustre on the re-plated case.

And, time time to put the hands back on.

And, lastly, re-case the movement and put the strap back on.

Thank you for taking the time to go through this rather long post. Soon, I will be selling this watch, and when we do, I’ll add a link to the page so you can view my other watches for sale.

Cheers