Service: Hamilton with Hamilton 60 / ETA 2390 Movement

 In Watchmaking

This Hamilton did run, but it didn’t keep time, the amplitude was very low, and it had a power reserve of only a few hours. If you wound it, you could feel and hear the mainspring slipping, so that pointed to a broken mainspring.

The movement is the Hamilton 60 which is an ETA 2390 with a KIF shock-protection system, and the stud carrier and regulator are slightly different.

The watch is in excellent condition, but the plating of the crown has worn down over the years because of use. Obviously, the crystal needed to be replaced as well.

Disassembly

Before you start working on a mechanical movement, make sure to remove all the power from the mainspring. This is to prevent any damage while working on the wheel train. In this case, it only had a small amount of power because of the problems with the mainspring.

Move the click away from the ratchet wheel while letting the crown slip between your thumb and index finger.

Flip the movement around and start with the motion work. It’s usually best to disassemble these parts first, at least as far as the cannon pinion. If you don’t, you won’t be able to lift the center wheel.

Hamilton with Hamilton 60 movement

The minute work cock, the minute wheel, the setting wheel, and the hour wheel with the cannon pinion removed. The cannon pinion and the driving wheel are one part.

Turn the movement around and lift the balance and the pallet fork.

Hamilton watch with Hamilton 60 movement

The balance and the pallet fork removed.

Remove the ratchet wheel and the crown wheel (reverse-fretted screw) and lift the barrel bridge.

Hamilton with Hamilton 60 movement

The ratchet wheel, the crown wheel with its ring, and the barrel bridge removed.

Lift the wheel-train bridge and remove the escape wheel, the sweep second wheel, and the 3rd wheel. Lift the barrel and the intermediate wheel.

Hamilton with Hamilton 60 movement

The top plate empty.

When I examined the barrel and the mainspring it turned out that the mainspring wasn’t broken. However, someone did install the mainspring upside down. That doesn’t help. I also noticed that both the hook of the arbor and the inside of the barrel were worn out.

I guess that the watchmaker before me gave up when a new mainspring and flipping it around didn’t work. I ordered a new barrel and lid + a new arbor and a new mainspring.

Flip the movement around and continue with the bottom plate. Remove the setting lever spring, the yoke with the yoke spring, the clutch wheel, the winding pinion, and the setting lever.

Pre-clean the pivot holes and bearing jewels with a peg wood.
Clean all the parts in the watch cleaning machine.

Assembly

Start with the set lever because this fiddly job is easiest with an empty plate.

Replace the intermediate wheel and the barrel. Place the escape wheel, the third wheel, and the sweep second wheel in position.

Hamilton with Hamilton 60 movement

The intermediate wheel, the barrel, the escape wheel, the third wheel, and the sweep second wheel installed.

Reinstall the wheel-train bridge and the barrel bridge.

Hamilton with Hamilton 60 movement

The wheel-train bridge and the barrel bridge installed.

Install the crown wheel with its ring. Place the click and the click spring in position and install the ratchet wheel.

Turn the movement around and start with the motion works. Don’t forget to lubricate the bearing jewel for the escape wheel before you place the cannon pinion with the driving wheel into position.

Hamilton with Hamilton 60 movement

The motion works and the setting wheel installed.

Reinstall the winding pinion, the clutch wheel, the winding stem, the yoke with its spring, and the setting lever spring.

Flip the movement to the top plate and reinstall the pallet fork and the balance.

Place the hour wheel (with the washer). Attach the dial and case the movement.

Fit the hands and use a hand pump to clean the inside of the crystal and the dial.

I fitted a new crystal because the old one was too badly damaged to polish it.

Hamilton watch with Hamilton 60 movement

What do you think of this Hamilton? Do you have a similar one in your collection? Let me know in the comments below.

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