Service: Medical Chronometer Zaria 2009B
I received this watch to take a look at because it sometimes stopped without any obvious reason.
This is a watch that is designed to look older than it actually is. The appearance of an enamel dial ( in this case, it’s painted metal ), the red logo and the red 12 marker are design elements from the 20s and 30s “trench watches”.
This is a 1970s watch with a Russian Zaria 2009B movement. A hand winder with 21 jewels. It’s quite small ( 8.75 Ligne) for a newer movement.
After inspection, I noticed that the movement was dirty and that the bearing jewels had run dry.
Time for a good cleaning and fresh lubrication.
I also polished the crystal while the parts were being cleaned in the machine.
The Zaria 2009B is much smaller than the dial and the dial was glued directly onto the movement.
Make sure you remove all power from the mainspring and lift the balance and the pallets.
This movement had a separate metal sheet that was between the base plate and the balance cock. I have no idea if this is standard procedure with all these movements. It would be a serious design flaw if it was.
Remove the hour wheel and the cannon pinion on the bottom plate of the movement.
As you can see, this movement has separate wheel-train bridges. One for the escape wheel and the 4th wheel. And one for the 3rd wheel, center wheel (which is not in the center) and the sweep second pinion.
Start with removing the lower bridge and lift the escape wheel and the 4th wheel.
Remove the other wheel-train bridge and lift the sweep second pinion.
Remove the ratchet wheel and the crown wheel. Actually, this movement has a ratchet wheel (with the reverse fretted screw) and an intermediate wheel. The intermediate wheel makes the barrel turn anti-clockwise.
Remove the barrel bridge and the main barrel. You can also lift the 3rd wheel and the center wheel with the center wheel bridge.
The center wheel bridge also covers an intermediate pinion between the barrel and the 4th wheel.
Flip the movement around to the bottom plate.
Remove the set lever spring and lift the minute wheel cover and the minute wheel. Then, move to the keyless works.
Remove the intermediate wheels, the return bar and its spring, the castle wheel, and the crown wheel.
Pre-clean all bearing jewels with a peg wood. Pay extra attention to the pallet stones and the pallets crown.
Clean all parts in the watch cleaning machine. I set the timer for 6 minutes on each cycle.
Begin with the main barrel, the intermediate pinion, and the center wheel bridge.
Reinstall the sweep second pinion, the 3rd wheel, and the center wheel and refit the bridge.
Position the 4th wheel and the escape wheel and reinstall the 2nd bridge.
Lubricate all bearing jewels with Moebius 9010 and the barrel arbor with HP1300 or D5.
Install the barrel bridge, the crown wheel, the intermediate wheel, and the ratchet wheel. Lubricate the shims of the crown wheel and intermediate wheel with HP1300 or D5.
Flip the movement around and install the minute wheel and the minute wheel cover.
Then, install the castle wheel, the crown wheel, and the stem. Replace the yoke and its spring.
Place the intermediate wheels into position and reinstall the set lever spring. Make sure to flip the movement around to press the set lever button. This will secure the stem with the pin of the set lever.
Lubricate the bearing jewels, except the one for the pallets, with Moebius 9010. Lubricate the barrel arbor with HP1300 or D5.
Turn the movement around and install the pallets (lubricate the exit stone with 9415).
Install the balance and give the movement a flick to start it running.
This particular movement had a metal shim between the base plate and the pallet cock. I had to reposition it before I screwed the balance cock all the way down.
With the balance installed, you can remove the endstone and clean and lubricate it. You can do the same on the bottom plate before you refit the dial.
The movement is running with a strong amplitude and isn’t stopping anymore. Sadly, because of the design of this movement and the fact that the dial had to be glued back on (I used dial stickers), the hour wheel is a bit loose. The hour hand will drift slightly with every hard tap.
It’s a shame but some watches aren’t meant to be serviced or repaired. I’ve repaired and serviced similar watches before but not all of them will “survive”.
Remember that if you decide to buy a (cheap) Russian or Chinese watch.
Do you have experience with watches like this? What do you think of it? Comment below.