Service: Omega Speedmaster calibre 1861

That last of the three watches Robert from Sweden sent me – a great looking Omega Speedmaster with the 1861 movement.

Let’s first see what the timegrapher has to say …

That’s pretty bad. Wavy, low amplitude, beat error could be better. This movement needs a good clean.

The movement is protected by a dust cover.

First look a the movement. Nicely decorated, beautifully constructed – relatively simple but well designed.

The bottom plate. All looks clean.

I start off by taking apart the bottom plate. You can see traces of lubrication on the plate.

Now it’s time for the top plate.

You can now see the heart-shaped cams used to reset the chronograph wheels to 0 position.

Just the driving wheel for the chronograph to take off, and I’m ready to get down to the movement level.

Two wheels and the barrel to take out, and we’re there.

All parts ready for the cleaning machine.

Reassembly starts as usual with a new mainspring.

Barrel closed.

The friction clutch is screwed back on the barrel lid. These screws are about the size of a nit 😉

As I put the movement back together, I follow the oiling chart step by step so I don’t miss a point.

The first part done – now it’s time for the top plate.

With the wheels and wheel bridges in, I carefully oil each tooth of the escape wheel.

And the movement is ready for a first look on the timegrapher.

After a first adjustment, this looks pretty good.

Now the chronograph components are mounted.

Here as well, I follow the oiling chart. There are also several checks to be carried out at various points of the reassembly.

The chronograph is complete.

Detail of the locking pin for the hammer. After a bit of trouble getting the reset to work, all is fine, and ready for casing.

The hands go on.

Centering the second hand for the chronograph is always tricky and takes a bit of time.

Final check.

Dust cover back on.

Beautiful chronograph with a dial that isn’t overladen with all sorts of stuff. This is a watch I would happily wear!

32 thoughts on “Service: Omega Speedmaster calibre 1861

  1. Hi there,

    Do you mind if I run a question by you?

    In the future, I am thinking about swapping the delrin brake in an 1861 movement for the equivalent metal blocking lever (part 1726) and blocking lever yoke (part 1818). It seems like the brake is directly accessible after removing the caseback and removable just by unscrewing the single screw that is holding it in place. Would you happen to know if you can remove and replace those specific parts without dismantling any other parts of the movement and just by removing/replacing that single screw?

    Thanks a lot for your help and have an awesome day!


    • Hi Danny,

      Not sure it’s a great idea to start working on watches on something of that value … This is sort of what watchmakers are there for … You will have to remove some other parts, and the chance of breaking your watch are fairly good.

  2. how do you let down the mainspring when you first decase the movement ?

    I’m replacing a dial and need to get the hands off which would be easier if the mainspring wasn’t sending power through the train

    doesn’t seem to be on the caseback side of the movement from pictures but i haven’t done this before

  3. Hi Christian, a bad watch shop, “ruined” my Speedmaster from the movement to dial and hands, the hands have crazy glue on them, it was a simple mainspring change, I bought hands and dial, how can we start rebuilding my watch, I really miss it, thanks, regards!!

  4. Hi, I’m a watchsmith but I rarely work on anything that isn’t Seiko. I serviced my own Speedmaster Pro, and the rebuild went beautifully in every single way except that the reset on the hour register is slow. Everything else functions perfectly. There’s no creep on that hand, and it will reset to zero, it’s just slow. Can you give any guidance on what I should be looking for? Thanks in advance.

    • Hi Spencer,

      It’s probably best to take the dial and hands off, and to watch what happens when you reset. There should be a distinct click when the hour hammer is pushed over the brake, and you will need a bit of grease where the two meet, especially around the pin.
      The most likely issue is the clutch for the driving wheel for the hour recorder, which sits on the barrel. It need to be well lubricated, so that it resets easily. Make sure that the surface between the wheel and the barrel lid is greased, and that the tension spring that holds it down also has a small amount of grease on its tips.
      Lastly, the hour recorder itself has to be lubricated top and bottom, but you have surely done that. A tiny bit of grease on the hammer surface where it touches the heart-shaped reset cam will help, too.
      Let me know how that goes. Best regards, Christian

      • When I replied, your response wasn’t showing. I should have refreshed the page. Thank you for your input. While I did lubricate of course, I lubricate sparingly and I needed to run the hour wheel around a few times. Snaps to zero cleanly now.

  5. Mine runs fast, and Omega says -3/+11 a day is within spec so sending it to be regulated is pointless. Mine is +9 daily and is brand new (2 weeks old). What do you think?

    • The movement isn’t chronometer grade, and as you say, yours runs within what Omega specifies. If you want a watch that’s super accurate, a £6 Casio will do the trick. Enjoy having a beautiful watch with a beautiful movement, and adjust it once a week.

  6. Hi,

    I just purchased a Speedmaster Pro with the Saphire display back. I’m a sucker for info and data. Do you have links to any maitenence manuals, plans, specifications etc? The more information you can share the better. also can you recommend any books. I love tinkering and would like to be able to get to the point where I can do all of the maintenance my self. Also where can I find replacement parts?

    Kind Regards,

    • Hi Matt,

      I’m afraid all that sort of info is restricted, and only accessible to certified Omega dealers. The same applies for parts. I suggest you start off with a couple of cheap watches from eBay, before you attack your Omega 😉

      • Dont worry. I dont plan on touching the inside of my speedy anytime soon. Could you reccomend a decent, quality watch/movement that I could learn on, one that would have readily available parts and instruction? Also any reccomendation on good tools and where I can get all of these things would be greatly appreciated.
        Im new to this hobby and I love it!

        Thanks much,

  7. I bought a used Speemaster ‘Moon Watch’,now approx 10 years old. just had it repaired and serviced with a new main spring ( it had broken).How often should it be serviced to maintain it’s condition.

    • I have the speedmaster professional (‘moon watch’). It’s five years old. On a full wind from dead stop, about 55 turns, the power reserve is around 25 hours. Omega claims 48 hours power reserve. The watch was recently serviced. Is the mainspring at fault?

  8. Wow… that is a lot of individual points to oil, and it looks as if those two images are a small sample of a lot more? You have the patience of a saint 😉

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