Service: Girard Perregaux Gyromatic HF 444-427

IMG_2641I wanted to share this watch with you, as the movement has many interesting and well executed features. Wynand sent it in for a service, and I’m happy to oblige…IMG_2643

Nice oscillating weight with a proper ball bearing, and of course the high-beat 36,000 b.p.h. 444-427 movement.IMG_2644

The amplitude is a bit low, but the beat rate is still very constant.IMG_2647

The 10 o’clock marker has come off the dial, and was lodged against other markers. The second hand is bent badly.IMG_2648

The second hand is bent in the up/down and the left/right direction…IMG_2649

The dial with the re-set marker. I put it back into place, and very softly re-riveted its studs.IMG_2650

Looks like the dial was restored once, and that’s why one of the markers wasn’t set properly.IMG_2651

The second hand in all its bent glory 😉IMG_2652

After a bit of fiddling under the microscope, it’s nice and straight again.IMG_2653

Lovely bottom plate.IMG_2654

Let’s start to take the movement apart.IMG_2656

The auto winder mechanism is lodged in a little opening at the top of the photo.IMG_2664

The gear train with the the hacking second lever below the gears and right above the barrel arbor. Lovely execution!


What do they mean by “Do not open”?IMG_2670

Now it’s time for the bottom plate.IMG_2671

A very snappy date change, with an unusual quick-set date.IMG_2675

Check out the long lever on the right – this is the quick-set date lever, which is operated by pushing in the crown and releasing it.IMG_2678

In this picture, you can see the friction clutch, which isn’t on the cannon pinion, but on the second wheel (the one driven by the barrel), and drives the cannon pinion via an intermediate wheel, which also serves as the minute wheel. Cool stuff.IMG_2688

All ready for reassembly.IMG_2689

The mainspring goes back into the barrel, after having grease the barrel wall with braking grease, and greasing the mainspring.IMG_2690

Now I put the balance jewels back in.IMG_2692

The base movement is back together, and you can see the space on the left reserved for the auto winder.IMG_2693

Nice and straight, and straight after putting the movement back together. The amplitude will increase in the next couple of hours.IMG_2694

Now I put the bottom plate back together. The tension of the friction clutch is determined by a circlips that fixes the pinion to the second wheel arbor.IMG_2695

The quick-set date lever is back in place.IMG_2696

And the bottom plate is complete and ready for the dial.IMG_2697

The auto winder is back in its slot.IMG_2698

And the movement goes back into the case.IMG_2699Nice watch, with a great movement!




14 thoughts on “Service: Girard Perregaux Gyromatic HF 444-427

  1. I own a G-P gyromatic which I purchased in the1940’s while on US Army assignment in Frankfort Germany. I would like your recommendation as to a very reliable technician who can make the Gyromatic mechanism viable (local watch repair has not been helpful). Thanks in advance for any help you can proviode. (note: while I live in Sacramento, CA, I’m within an hours drive of San Francisco).

    My e-mail;

  2. How do you set the date on a Girard perrigeaux gyromatic date watch from the late 50’s?
    Thank you

    • Hmmm …. “from the 50s” isn’t a very accurate description of the watch. My guess is by moving the time forward or backward… 24 hours make one day.

  3. How exactly does a gyromatic movement work?

    It is different from a mechanical automatic watch?

    You cannot hear the rotor moving around, so how does it keep the watch working?

    And is this movement a type of automatic?

    I just purchased a Girard-Perregaux gyromatic watch that is from 1955 and it has a beautiful ticking sound to it, much different from other watches that I own.

  4. A masterful job. I didn’t know GP made a fast-beat Gyromatic. I have a GP Gyromatic from the late ’50’s; 17 jewels, no complications; front loader in nice case. It has undoubtedly the same base movement as your example, although I would expect a beat rate of about 18,600 bph. I stopped wearing it years ago when the watches became bigger. It’s 32mm and that is a bit small these days.

  5. My heart sank when I saw the dislodged marker and damage! Thank you for sorting it out Christian. It on my wrist and looking lovely.

  6. Very nice watch! I’ve got a Mido Commander somewhere in a drawer with the same AS movement 🙂 (Mido 1157OCD or AS 1920)

    • GP did some modifications to it so they are not completely identical, but the basis calibre is of course the same.
      I think you will find the regulator to be different amongst other.
      Cool calibers!

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