This Seamaster GMT came in for a service and I thought you may find it interesting to see the insides of the calibre 1182 movement. The 1128 is based on the ETA’s calibre 2892-A2 so it should look reasonably familiar!
The back shows this is a 50 year anniversary model so I would presume it was released in 1998 as the original Seamaster first appeared in 1948.
With the back removed the usual soft iron anti magnetic dust cover can be seen.
Once that’s off the movement can now be seen, It’s highly decorated with perlage and Geneva stripes. This particular 1182 is also chronometer rated so has improved accuracy over standard ébauches.
It’s easier to remove the autowind mechanism whilst the movement is still cased up, once I’ve got it out you can see more of the train work.
With the weight and bridge removed you can see the autowind train is very compact.
I then uncased the movement, the hands are lined up here ready for removal.
Underneath the dial is the calendar work, again highly decorated with perlage, or engine turning as it’s sometimes known as in the UK.
Once I’d removed the calendar disk and 24hour wheel the top plate for the rest of the mechanism can be seen.
I removed this and the wheel train is situated underneath. The hour wheel has a clutch mechanism built in to be able to independently set the hour hand quickly to different time zones.
The keyless work looks very familiar, you can certainly tell it was originally an ETA.
With that removed this side was done.
I then turned the movement over to start on the motion work.
In this shot I’ve taken the power off then removed the balance and pallets.
Next to go was the train bridge….
….then the barrel bridge could be removed.
The bridge has some components that would usually be on top situated underneath like the click mechanism.
This meant everything was now ready for cleaning and inspection.
Everything appeared to be in tip top shape, even the mainspring so I started the rebuild with that.
Reassembly is the reverse of dismantling as the Haynes workshop manuals used to say!
Once I have it at this stage I demagnetise the movement then roughly time it up on the timing machine.
Then it’s turned over and the calendar side is reassembled.
I forgot to take a picture of the dial and handset refitted on so it goes straight to recasing here! Just the autowind mechanism to refit now.
It’s now ready for closing up and testing.
And it’s ready for a few more years service now, I must admit I do like the Seamaster range of watches, something for everyone it seems.