Service: Omega Seamaster calibre 501

Lots of 501s lately… and nothing is wrong with that, as it’s a great movement. Especially the fact that you can press the second hand on without having to support the arbor from the back 😉

Christie sent this one in, and it has problems stopping and she suspects the auto winder.

This is enough reason for the watch to stop from time to time. A very low amplitude, and the watch is too slow. My guess here is that a good clean and a new mainspring will resolve the issues with this watch.

The set lever spring is broken, meaning that the winding stem won’t snap into plate properly. It’s available, but not cheap.

The top plate comes apart.

Having taken the watch apart, I’m ready for the cleaning machine.

The barrel gets a new mainspring.

The top plate is back together and the balance is swinging.

Compared with what I saw before, this is pretty good.

With a new crystal, we’re back in business.

12 thoughts on “Service: Omega Seamaster calibre 501

  1. I got a new mainspring and my watchmaker put it in.
    The amplitude is now up to 220 at max but the beat error is about 2msec.
    He tells me he has to take the balance out for regulating the beat error.
    That is not what I understood in my short learning curve on adjusting the beat error.

    Can you assist pls.

    Thanks Bern d

    • I am not quite sure what you are doing here. If you don’t trust your watchmaker, why are you giving him your watch? By the way – he is right…

      • Well it is not about trust, it is about the decision to take the balance out again and adjust it.
        The amplitude right now is 210 at best with a lift angle of 49,5 that I found.
        Wonder if the amplitude will improve as well if the beat error is regulated.
        Sorry for my stupid questions but curiosity is one of my flaws.
        😉

  2. I have a 501 watch too and I need a new mainspring.
    Can you help and point me to a source please.
    No success so far when searching.

    Best Bernd

  3. Do Omegas generally have Swan Necks? I noticed that 712 you did a while back had some other arrangement but forgot to ask about it, and one of the smaller ones you did more recently was just a standard arrangement… what decides if a movement gets one or not?

    I really like the design and execution of this movement 😉

    • To my knowledge, all chronometer certified Omegas have swan necks, and some of the other movements as well, but I can’t really see a pattern. Might have been the choice of breakfast of the designer 😉

    • hi there hope you can help,i have the same watch caliber 501,seamaster,
      the movement number is R 56074,i dont know how to date the watch as it normally has a 8 digit number with no letter,the numbers and the letter R is were the movement number is normally stamped,i do service omegas and i do know most things about all omega movements also i can service all calibers,but i have never seen the movement number like this,hope you can help thanks chris

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