# Seiko Sealion M55 Service



## Thewatchbloke (Feb 25, 2011)

I picked up this 1965 6206-8001 from the bay back in October as a non runner.. It had a nice dial and handset so I thought it'll make a nice little project when I have the tools and time. The watch arrived and true to the description it wouldn't run - at all. Also when setting the time and date it was very difficult to get the hands or day/date wheels to move as the keyless works were slipping and jumping all over the place, the achillies heel of the 62xx calibre.










Anyway this weekend I decided I had collected enough tools to tackle a service on it. I have regularly dabbled with watches to the extent of removing movements, changing crystals, hands, dials etc, but I have never had the testicular fortitude to tackle a full movement strip, clean, lube and re-assembly. Uncharted territory for me.

It didn't take long to remove the rotor, take the movement out then take the handset, dial and daywheel off and it soon looked like this:










If you notice there is a tiny spring to the right of the 10 and 9 on the datewheel that applies pressure to the daywheel locator. When I removed the plate that holds this spring in place (you guessed it) it went flying! I knew about the small spring underneath the plate that does the same job for the datewheel locator because it is similar to the 62mas and I have changed datewheels over on those calibers before.










So that was the first calamity, I searched and searched on table, the carpet, my lap, everywhere but it was gone. Not a complete disaster as I have a couple of 6206 donor movements so I could always harvest one from them.

So I carried on stripping the plates and levers, datewheels and calendar gears until I was left with just the keyless works on this side of the movement:










I removed the keyless works (which were absolutely shot) until I had a clean mainplate (I took the picture before I had removed the stem release pawl and cannon pinion):










It was now time to flip the watch over and start on the winding mechanism:


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## Thewatchbloke (Feb 25, 2011)

I removed the winding bridge and stripped it, I think that Seiko's winding mechanism is simple and robust - a great piece of functional engineering. Brilliant!:



















I'm now down to the heart of the watch, mainspring barrel, balance and wheeltrain:










Off came the click and the gear it operates on, then I removed the main bridge to start to expose the wheel train:










Next to go was the balance ****, balance and third and fourth wheels:










Then the pallet brige and pallet, and escape wheel bridge were next off:


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## Thewatchbloke (Feb 25, 2011)

The mainspring barrel and escape wheel were removed:










And finally the centre wheel was removed and everything was in my container:










Once it was in this state I collected all the wheels (apart from the mainspring barrel) and gave them a good seeing to in the ultrasound bath. Next in the bath was the mainplate and all the bridges. When these were done I did the fiddliest job ever and pegged out all the jewel holes. I even removed the jewel caps and cleaned underneath them with alcohol!

Because I had lost the tiny daywheel locator spring I did this all again and stripped another 6206 movement I had. This had the benefit of a keyless works that actually worked so I needed that anyway, it wasn't really time wasted!

Anyway I took a few snaps of some components after hand cleaning or finishing them:

Mainspring barrel:










Bridge, pallet and third wheel:










Pallet bridge:










Once everything was clean, I started on the re-assembly, lubricating the jewels with the tiniest amount of oil as I went along:


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## Thewatchbloke (Feb 25, 2011)

It felt great once I had the wheel train and pallet in place and gently applied pressure to the barrel to test if it worked. The pallet fork started flying back and forth and I knew that I had assembled it correctly!

The trickiest part out of the whole rebuild for me was getting the balance located properly in the jaws of the pallet fork. After about five attempts it was in and a quick shake showed that it lived!










The winding bridge and gears went on and that was the engine side of the mainplate done:










These little blighters are the 62xx calibres weak spot. The date corrector and stem gear do wear badly and once they have worn setting the time and date becomes almost impossible on bad cases. Luckily the spare movement I stripped had a good pair of these:










The keyless works were reassembled and lubed:










Then the calendar mechanism with a new datewheel was refitted:










The daywheel and the dial went on:


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## Thewatchbloke (Feb 25, 2011)

The handset:










On with the movement retaining ring and back in the case:










The rotor and a new caseback gasket were fitted:










The caseback was screwed on:










And she's running like a top!



















It's taken me a good portion of Saturday and Sunday to do, but I was going into it blind having never attempted anything as in depth as this before. To say I'm pleased is an understatement though, it's given me an immense feeling of achievement to know I have actually serviced a non running watch and got it back to good health.

Apologies for the less than perfect pictures, and I'm sure some of my terminology is wide of the mark but I can only improve!


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## jnash (Dec 6, 2010)

Great work....


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## BroDave (Sep 27, 2010)

Mine says hello...


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## tixntox (Jul 17, 2009)

A brilliant job, well documented. I'll have to remember to bookmark this one. I shall have to remember to take more pics when I work on my next one. I tend to just crack on and then it's too late. Well done you. Excellent work.

Mike


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## Service Engineer (Dec 28, 2007)

One of the most interesting posts I've had the pleasure to read in a long time.

Great pictures and it's nice to know I'm not the only one who has parts fly off things never to be seen again when they strip something down. Fortunately you had a donor to salvage the spring from.

Well done. I admire your courage and confidence. An encouraging post for the rest of us not so nimble fingered.

Your obvious pleasure with this project shows but there's not a trace of a show-off attitude or boasting. Very impressive.

Thank you for taking the time to post this.


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## Dusty (Feb 3, 2010)

Nice Job well done :thumbup:


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## MerlinShepherd (Sep 18, 2011)

That's a joy to see! I love watching the slow deconstruction and fine pics that you took. I would be so pleased if I had done such a thing. I've done it many times with flutes, clarinets and saxophones but never with something so intricate as a watch. I am impressed!


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## Thewatchbloke (Feb 25, 2011)

BroDave said:


> Mine says hello...


Very nice, I have one of those models too - is that the 6206-9000? In fact I have quite a few of these 6206's. Bit of a weak spot of mine


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## Tony1951 (Dec 23, 2011)

That was really interesting and an encouragement. The pictures and descriptions are first rate. I bet it feels great to have a success like that. Thanks for the report.


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