Service: Longines Ultra-Chron calibre 431

IMG_8467Steve sent me this lovely Longines Ultra-Chron. Ultra because the calibre 431 beats at 36,000 bph, so 10 beats every second.

The rotor of the auto winder blocks sometimes, and it needs a service.IMG_8468

The case back gasket is nicely warped, but that gets replaced anyway.


A first look at the movement – all looks well and in good shape.IMG_8470

The dial is also looking good.IMG_8471

Onto the timegrapher to check what the movement is doing.IMG_8472

That doesn’t look great, and it’s high time for a service.IMG_8478

The gear train exposed.IMG_8484

Most high-speed movements have closed barrels, e.g. you replace the whole barrel to change the mainspring. Not cheap, but at least I can get hold of a new one.IMG_8485

A very tidy bottom plate as well.IMG_8540

The new barrel with mainspring.IMG_8541

And I can start the reassembly of the movement.IMG_8543

The basic movement is back together, and ticking.IMG_8544

Not bad for a start!


The clutch wheel of the auto-winder sometimes jams, but a good clean and lubrication sorts out the problem.IMG_8545

Now the auto-winder bridge goes back on.IMG_8546

I turn the movement around, and start reassembly of the bottom plate.IMG_8547

The date change mechanism is super-snappy, and a great construction.IMG_8564Β Time to case.IMG_8565

Final adjustment on the timegrapher.IMG_8567

Dial down, I adjust ever so slightly fast.IMG_8568

Back into the case, and with a new crystal, it’s a beautiful watch.IMG_8570With a beautiful movement inside!


59 thoughts on “Service: Longines Ultra-Chron calibre 431

  1. I have a Longines 431 my wife gave me around 1970 something iI think. I snagged it on something and pulled out the male stem. I can not find one. Can you help? The watch means a lot to me because of my wife.

  2. Hi, nice job.
    I have one ultra-chron for servise now, where an iron plate under the rotor barrel is missing (visible on Your foto no. 14 of this article).
    Is it possible to get one from if You have it?

    Thanks for answer in advance.

  3. Pingback: Vintage Longines Ultra Chron

  4. Hi Christian,

    Amazing work as always but I have a question and not sure if you can help. I got a cal. 431 and sent to my watchmaker, he said the “reversing wheel” on the automatic winder is damaged so I am trying to see from where can I source another reversing wheel. Can you shed some light or maybe a part number would be helpful as well.

    Thanks in advance,

    • Hi Gary
      My ultra-chron had exactly the same problem, with a broken reverse wheel, and a rotor turning like helico gears…I wasn’t able to find ONE new for replacment, and after several year a guy was selling some on E..y, second hand but working well. If you love your Ultra-chron as I love mine, it can be a good idea to watch for bad movements, or bad looking watches, just for parts.
      Good luck !

  5. Hello Christian, was just browsing and found your site relating to a Longines Ultracron Calibre 431. I have one which was given to me by my then fiance now my wife in1972. I have hardly worn it and it is still in its case. It is an 18 carat gold watch. Can you give me further info and am I doing harm to it not being used. Would you also know know approx value. It as it looks brand new.
    Anthony Bartolo

  6. Hello there, lovely work – what do you think the power reserve on this movement would be?

    I am servicing one myself as we speak and I am struggling with amplitude.
    Max 240 in the flats.
    It has a new barrel (from the 6641 – I believe this is the same strength).



  7. I own a gold plated Longines Ultraxron watch, with a gold bracelet. The watch works allright but I cannot set the time (the knob is runnuing fool). Longines asks for 1453 € for full repairs…! It seems to me to be well over the actual price of such a watch. Any opinion ?

  8. I have a Longines Ultra Chron 431 movement and just wondering if that mechanism can be replaced with a quartz movement..(battery)?????

  9. Hi Christian,

    Just happen by chance stumble here and I must say you did a fantastic work restoring that timepiece. I had the same exact model which need the same treatment.
    Should I pm you?

  10. Hi Christian,
    Great watch and I appreciate your posts. I need a little help. I have a Longines Ultra-Chron with the 6651 movement. Is there something that is supposed to hold the hour wheel in place? Mine seems to move and disengage obviously causing the hour hand not to advance. I know most watches have that gold spring washer to hold the hour wheel in place but that doesn’t seem as it would do the trick on this particular watch. I’ve looked for diagrams online but I all find are part lists with just numbers but no part descriptions. Any help would be appreciated.


      • Christian,
        Thanks for your response. I disassembled/reassembled and everything seems to fit together as it should now. My new issue (probably related to the original issue) is that the minute and hour hands only move when setting. I’m guessing I have a loose cannon pinion. I’ll try tightening it a bit to see what happens. Thanks again.

  11. Hi,
    Found Your page , text and pictures- superb.
    As many other readers, I have a question regarding Longines 431- super cron problem.
    I got the watch a month ago and found out that the balance hairspring is damaged.
    Is it repairable or need a new one?
    Where I can buy the part?Thank You.
    Best regards from Macedonia.

  12. I have this movement. Date is not changing, pawl is not quite gathering next tooth. It is as if it is not being drawn back quite enough. it’s not restricted to any particular tooth. Bought another movement, but it is doing exactly the same thing. Any comments? Regards, Bill.

      • Hi Christian.Yes that’s what I thought. Just seemed strange that 2 movements are showing the same fault. The part of the cam that contacts the pawl is a bronze material so maybe it wears. Bit disappointing for a Longines watch. Anyway thanks for your help and it’s very generous of you to share your knowledge with amateurs.
        Bets regards, Bill.

  13. Christian what lubricants do you use on the pallets and escape wheel in these high beat movements ?

  14. You could open the old mainspring barrel and check it out to see the condition of the grease.

  15. Hello! I have a Longines Calibre 431 and was told that it needs a sealed mainspring barrel, and that it was impossible to get this part anymore. Is this true? Thanks!

      • considering your experience as for what i see on your beautiful blog, i totally trust you about watches.

        only i can’t stand anymore receiving any kind of stuff in my mailbox. it’s not you. it’s the net, which is based on knowing what i prolly want and what i prolly like to forcefully put a price tag on my neck. if you google my fifteen years ago mail address you can still find any kind of comment i made about netscape vs ie, or about the new look of aol front page.
        really does the world need it? i don’t think so.

        (beside that, i can trust you, but i can’t trust wordpress’ helvetic cheese safety score at all… )

  16. Just as a side note to the repair. I contacted Longines to find out the birth date of the watch and I was surprised that, not only did they reply but they informed me that this “431 movement was first produced in 1967. This particular watch was produced on 01.06.1970. It was invoiced to Longines-Wittnauer, who were for many years our agent for the USA.”

    I know many probably know about dating watches but I noted the Longines movement numbers suffer after 1969 in being accurate regarding dating.
    The trainee heritage member of staff informed me they have archives with old watch information.
    Rather nice and just adds a little extra to owning such watches.

    • That is pretty impressive – you got the exact date of manufacture! I was 5 when your watch was made πŸ˜‰

      Same age as the Omega Constellation I’m wearing …

      • Hi Christian
        I was indeed -4 year old on that date myself. I was quite pleased about the reply as I thought it would be a shot in the dark.
        Don’t mention constellation watches as I have yet to be “happy” with mine!

  17. Hi Christian.

    Thank you very much it looks great from here! I am looking forward to using this watch. My wife even looked at your blog and said….is that yours? I think your photos give it that extra zing.

    Cirrus. I am sure this question has been asked several times and you may well never be sure. Would be interesting to open one up to have an idea! What is the other option on replacement though?

    • I suppose if you were really paranoid you would buy two barrels, open one – very carefully – examine it to see if it passes muster and, if so, use the other πŸ™‚

      I don’t know if you can re-fit these high-tension springs once they have shot across the room and / or taken your eye out…

      • As the Chinese proverb goes

        Man with one watch always knows the time-man with two is never really sure! I will leave the paranoia out as I am not sure who is reading this!

        I have never taken a mainspring out of it’s barrel. Should this be something all watch lovers do I wonder.

        Thanks again

  18. A beautiful watch, inside as well as outside.
    Is the mainspring barrel cloes because of higher tension?

    There’s a typo in the topic title btw (Logines instead of Longines).

    • Yes, the mainspring will be under considerable tension, with the power reserve and the fast beating movement. Same with the Zenith El Primeros, they also have a sealed barrel.

      Thanks for pointing out the typo – it’s fixed now!

      • If you buy a sealed barrel can you be certain it hasn’t dried out in storage?

        Lovely looking watch – got to love those high beat movements πŸ™‚

        • I’d say barrel grease will last quite a long time if stored properly, and you can see that the barrel came in its own sealed container. Should do a couple of decades πŸ˜‰

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