A client has sent in his father’s Seiko Bellmatic calibre 4006A. This must be one of the more pretty models in my opinion. It runs intermittently and needs some attention.
Watch runs a little on and off and the amplitude is not great.
Movement does not look too bad.
I start by removing the Oscillating weight.
I now remove the autowinder construction.
Alarm ring is held in place by two brackets.
After removing the dial you can see the day and date disk.
I start by removing the day/date mechanism.
Day/date mechanism has it’s own plate.
Removing the day/date plate reveals the alarm setting mechanism.
Slowly does it. I have the Seiko manual for these movements, but taking lot’s of photos for the archive really helps when putting the movement back together.
The setting lever for the alarm has some corrosion.
There is some rust on the alarm setting lever, but I think it will clean up nicely.
After removing the setting mechanism I turn to the gear train.
Old mainspring for the gear train.
Movement cleaned and ready to be put back together. I have cleaned the alarm mainspring as well.
I start by fitting the alarm mainspring.
I now see that the balance moves freely with the jewels in place.
I now fit a new mainspring for the gear train.
Gear train goes back in place.
I now have a running base movement.
Watch is preforming well.
Setting/winding mechanism coming back together. The alarm setting lever cleaned up nice.
Now for the day/date mechanism.
Day/date disk in place.
I now place the movement back in the case with the autowinder mechanism.
Movement back together and working.
I think this must be one of my favourite Bell-Matic dial designs:)
I did extensive testing on this watch and it kept stopping randomly. After a lot of dead end theories I noticed the upper barrel arbour bush was worn causing the barrel to tilt at certain positions causing the watch to stop.
It was hard to find as the bridge did not feature the usual scars from a worn barrel arbor bush.
I had a jewelled bridge available that fitted perfectly. And I would say that is a pretty neat little upgrade.
After testing the watch, it was finally ready to go back to it’s happy owner.
5 Responses to Service Seiko Bell-Matic 4006-6021T
Hi Mitka, fantastic work as always! I hope to be able to do a complicated movement one day. A question or two really. Do ou clean the screws as well? And on this movement how does the alarm function set?
Thank you and thank you for sharing with all of us!
Gary
Hi Gary,
I clean all the screws, some exceptions are when the screw is extra little and has a high risk of being lost I will clean it in Rodico only.
Alarm and hands setting is made by the same crown (unlike many other alarm watches) The crown has 3 positions. winding, setting, setting.
Gary,
While you’re learning, before cleaning, you can replace the screws back into the appropriate holes. You can also take detailed pictures of the screws and its plates. Hope this helps!
Brandon
This was my Dad’s watch and the job that Mitka did was amazing. I had searched for over two years to find someone who would take on this work and it is a joy to be able to use this watch on a daily basis. I can’t thank Mitka enough for restoring a family heirloom.
Thanks for the kind words Phil, glad to hear your happy with the work:)