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.