Omega Seamaster 600 model 135.011 Calibre 601 Service & Restoration

Today on the blog is this Omega Seamaster 600 model 135.011 in need of a bit of TLC. I purchased this watch at a local auction with the intention to return it to its former glory. The watch dates from 1965, and it is powered by the manual wind Omega Calibre 601, an excellent movement capable of great performance.

Omega Seamaster 600 Calibre 601


Omega Timegrapher Reading



I place the watch on my timegrapher after a full wind, and the reading is typical of a very very sick movement. It is barely running, with very poor amplitude and timekeeping.




After opening the case, things are looking up, the movement looks relatively clean with no sign of corrosion or obvious issues. The rhodium plating on the friction spring bridge is a slightly different shade to the rest of the movement, possibly an earlier replacement.Omega Calibre 601 Service


The dial has aged quite badly, there is pitting and this will not clean off.Omega Seamaster 600 Service


Omega Damaged Hand


The hands are also in poor condition, and I believe they are not original to the watch: the hole in the minute hand has been closed in the past to fit the cannon pinion, probably using a staking block, punch and a hammer by the looks of it. As the seconds hand is missing, I take the decision to source new hands, hour minute and seconds.



New hands would look odd on an aged dial, so although I usually like to keep dials untouched I think that on this occasion it is the right thing to have the dial restored.

The dial is sent for restoration, and I can carry on with the service, starting with the dial side.Calibre 601 Dial Side


There is not much to it, with no date complication on this model.Omega Calibre 601 dial Side


I then move to the other side. Note the nice eccentric regulator used on this movement. Omega Calibre 601 Balance side


Omega Calibre 601 Friction Spring

Here you can see a close up of the sweep seconds friction spring, which holds the indirectly driven pinion and prevents the infamous seconds hand “stutter”. This design is widely used on Omega movements of that era.



I progress with disassembly, the winding mechanism has now been removed.Calibre 601 during service


Calibre 601 Barrel and train wheels



Barrel, train wheel and bridge are disassembled.





And I soon have the movement fully stripped down.Omega Calibre 601 stripped down


All the parts look immaculate after the ultrasonic clean, and after careful inspection I am pleased to find that none of them require replacement. Omega Calibre 601 after clean


The rest of the service is pretty straightforward. The watch came back to life as I was hoping after a good clean, a new mainspring and the correct lubrication. The hairspring required a little adjustment to get the best out of the movement.Omega Calibre 601


Omega Seamaster Case lightly polished

I then turn my attention to the case. It is in reasonable condition, but I give it a light polish to so that it fits in with the look of the restored dial and new hands.




The crystal is replaced. It could have been polished easily as it is acrylic, but the size of the old crystal was incorrect, with the tension ring providing insufficient tension of the crystal against the case. The Seamaster is a divers watch, so it is important to have the correct fit for water resistance.Omega Seamaster Crystal Replacement


The project is placed on hold for a little while until I receive the restored dial. It was worth the short wait as it looks absolutely stunning.Omega Seamaster Restored Dial


This gave me the time to source and fit NOS (New Old Stock) Omega hands. I also replace the stem and fit a new Omega crown (the old one was a generic unsigned version).Omega Seamaster Crown and Stem Replacement


And finally the watch is fitted with a new leather strap and Omega stainless steel buckle. I am very pleased how this project has turned out. This watch is everything I like about Omegas of that era: a great movement, and an understated, classy and timeless design.Omega Seamaster 600 model 135.011 Serviced

6 Replies to “Omega Seamaster 600 model 135.011 Calibre 601 Service & Restoration”

  1. Hi great blog. And you do a great job on the watches.
    I don’t suppose I could ask if you would please always take a pic of the watches on the timegrapher before and then again after the service. Just I think it’s interesting go see the performance after the work done compared to how bad they were beforehand.
    Many thanks

    1. Hi Aidan
      Thank you for your feedback, I am glad you like the blog!

      You raise a very interesting point here. I have thought long and hard about including timegrapher pictures after a service, and in the end decided not to, I will briefly try to explain why here. Watch regulation and adjustment is a very complex subject, and one timegrapher photo does not tell the full story.

      Which photo should I show? One taken straight after the service? A couple of hours later when the lubricants have settled (amplitude is then improved)? Fully wound? 15 min after a full wind, or 1hr, or 24hrs? In which position? I would check all these and more as part of the process of regulating a watch, and one picture out of context is pretty meaningless because there are so many factors taken into consideration.

      The other issue is that to the non trained eye, the expectation is a rate value on the screen as close to 0 sec/day as possible. In reality it is a bit more complicated than this, and a watch needs to be regulated in different positions (usually 5). One important set of data is the extreme rates in different positions (e.g. -4/ +6 for a chronometer rated watch). So if I show a photo of a watch showing say +6 sec on the timegrapher, people might think it’s not that good, when the watch is actually as good as it was when it left the factory, and may well be spot on on the wrist (because if it is regulated correctly the extremes will cancel each other when the watch is worn).

      Amplitude and beat error values also need to be looked at as part of the context. I do however provide my customers with some feedback after a service e.g. the rate they can expect on the wrist, based on the results I record during testing.

      I hope this goes some way to answering your question!

  2. What a delightful read!

    I’m puzzled with dial restoration. Do you have any insights? Can you tell where you sent this one? Do you do any restoration?


    1. Hi Julian
      Thank you very much for your kind words. I will email you the details of my contact for dial restoration. It is a very specialist job which I would not dream of attempting myself! In some instances I clean dials myself. Excellent results can be obtained, but it is all too easy to make things worse!

  3. Hi, what a fantastic job!

    I have exactly the same watch – could you tell me when you found the new hands?

    1. Hi Scott, thank you very much.
      Long time ago, but I am pretty sure I bought hour and minute hands on eBay, and seconds hand from CousinsUK.
      Best regards

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