The serial number is 2268680 and that dates this watch to 1949. One of the very last of this caliber to be made.
This Tissot needed a service because it was gaining time and the amplitude was (very ) low. It also needed the crown replaced. The minute hand had lost most of the lume and the hour hand was getting critical as well.
With the approval of the owner, I relumed the hands.
Remove any power from the mainspring and remove the balance and the pallets.
Remove the hour wheel and the cannon pinion on the opposite side of the movement. Without the cannon pinion removed, you can’t remove the center wheel later.
Because this cal. 27 doesn’t have shock protection, the balance needs to be dismantled further.
The balance cock, index, and the balance endstone can be cleaned in the watch cleaning machine. You can ungrease and clean the balance complete in One dip or something similar.
Remove the ratchet wheel and the crown wheel and lift the barrel bridge.
Lift the wheel train bridge and then take out the wheels of the train gear. Finally, remove the main barrel and flip the movement.
Remove the remaining motion works and then continue with the keyless works. This particular movement had a broken set lever spring. Luckily, I was able to pull an intact one out of a donor movement lying around.
Clean the parts in the watch cleaning machine. I use L&R #566 cleaner and L&R #3 rinsing solution.
Start with the main barrel and the gear train. Install the wheel train bridge.
Fit the barrel bridge, crown wheel, and the ratchet wheel. I polished the crown wheel and the crown wheel screw.
I used a glass fiber pen and then I polished them with a paste of Diamantine powder and some regular sunflower oil.
Turn the movement around and start with the motion works and the keyless works. I pulled the set lever spring out of a movement I keep for spares.
I think it won’t take long for this set lever spring to be obsolete. A lot of parts for the cal. 27 already aren’t available anymore.
Flip the movement to the top plate again to fit the pallets and the balance. Naturally, before you do so, you have to reassemble the balance.
Fit the hour wheel with its washer and fit the dial. Like I said, I relumed both hands. My goal was to approach the original color as best I could.
Finally, I fitted a new crown and I polished the crystal.
Do you have a Tissot Antimagnetique too? Tell me about it in the comments below.