Service: 1940s Roamer with MST 372 Movement

This is the third Roamer with an MST 372 movement on WahaWatches. That’s not surprising because I’ve serviced and repaired many Roamer watches and the MST 372 was a very successful movement that they used for a long time.

It’s the first version without any shock protection though. The fact that it doesn’t have shock protection tells you it’s an early edition. It matches nicely with the 1940s style of this watch.

Disassembly

As always, make sure to remove all the power from the mainspring before you start working on a movement. This is to prevent damage to the pivots of the wheel train.

Move the click away from the ratchet wheel with a peg wood and let the crown slip between your thumb and index finger. Don’t let go of the crown because the mainspring will unwind with a snap which can cause the spring or the bridle to break.

Lift the balance, the balance cock, and the pallet fork and store them somewhere safe. I always use a parts tray with a cover.

Turn the movement around and remove the cannon pinion, otherwise, you won’t be able to lift the center wheel. Flip it back to the top plate.

Lift the wheel-train bridge to get access to the wheel train.

Remove the sweep second wheel, 3rd wheel, and the escape wheel.

Remove the ratchet wheel and the crown wheel (note all that black grime around the crown wheel screw) and lift the barrel bridge.

Remove the center-wheel cock and lift the center wheel and the barrel.

Flip the movement around and start with the bottom plate. Remove the motion works and the keyless works.

Pre-clean the pivot holes and bearing jewels with some peg wood.

Don’t forget to remove the endstones and remove the old lubrication with the peg wood as well. The screws for the endstones are very small so be careful not to lose them.

Clean all the parts in the watch cleaning machine.

Assembly

Install the set lever and the set lever screw. Hold the set lever in place with your thumb while you use the other hand to screw down the set lever screw. Make sure to use finger cots because you cleaned the movement.

Lubricate the 2 endstones with Moebius 9010 and reinstall them.

Turn the movement around and start with the barrel, the center wheel, and the center wheel cock. Lubricate the post of the center wheel and both sides of the barrel arbor with Moebius HP 1300.

Place the escape wheel, 3rd wheel, and the sweep second wheel (lubricate the post with a tiny bit of Moebius HP 1300) in position and fit the train-wheel bridge.

Place the barrel bridge into position. Lubricate the crown wheel ring and the top barrel hole with Moebius HP 1300. Install the crown wheel and the ratchet wheel.

Turn the movement around and start with the bottom plate.

Start with the keyless works and then move to the motion works. Lubricate the cannon pinion post, the setting wheel post, the castle wheel, the crown wheel, and the connection point between the pin of the set lever and the check spring with Moebius 9501. Lubricate the bottom barrel arbor hole with Moebius HP 1300.

You only have to lubricate the 3rd wheel jewel bearing with Moebius 9010. The balance and the escape wheel are covered by the endstones and you never lubricate the jewel bearings of the pallet fork.

You can place the hour wheel and dial washer in position just before you fit the dial.

Flip the movement to the top plate and reinstall the pallets and the balance. Lubricate the exit stone of the pallet fork with Moebius 941.

I fitted a new crystal because the old one was beyond repair. A crystal with a low dome looks great because it enhances the sleek profile of the watch. I also replaced the crown because the original crown was worn out after 70+ years of use.

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