This Roamer cushion model was in need of a service. It did run for a little while but it almost immediately stopped again.

The owner sprayed it with WD40. I already scolded him and he did apologize for this horrendous act šŸ˜‰

Seriously, that is not a good idea. WD40 attracts dirt and dust, it clogs bearing jewels and it makes the windings of the hairspring stick together. Sticking hairspring windings will cause the watch to run erratically and much too fast, like severe magnetism.

The movement is an MST 264. This is one of the bigger movements with 12 ligne.

Looking at the (lack of) shock protection, this is an earlier model. Circa late 1920s or early 1930s.

Disassembly

Remove any power from the mainspring. Hold the crown between your thumb and index finger and let it slip while you move the click away. You can use an old oiler or a pair of tweezers to move the click away from the ratchet wheel.

Roamer MST 264

It’s clearly visible that the windings of the hairspring are sticking together. A clear sign that the movement is very dirty and oily

Remove the balance and the pallets.

Lift the cannon pinion at the bottom plate of the movement. You can’t lift the center wheel if the cannonĀ pinion is in place.

Roamer MST 264

The balance and the pallets removed

Remove the ratchet wheel and the crown wheel and lift the barrel bridge.

Roamer MST 264

The ratchet wheel, crown wheel, and barrel bridge removed. You can see that there are a lot of signs of wear and the movement is very grimy

Lift the wheel-train bridge and remove the escape wheel, the 4th wheel, the 3rd wheel, and the center wheel.

In this particular case, the bridges of this three-finger wheel-train bridge are all separate. Later MST movements (and Buren movements, for example) have similar looking bridges but they are 1 piece.

Lift the main barrel.

Roamer MST 264

The top plate completely empty

Turn the movement around and start with the bottom plate.

Remove the motion works and the keyless works. Don’t forget the balance capstone.

Roamer MST 264

The bottom plate completely empty

Pre-clean all the grease with Rodico and the bearing jewels with a peg wood.

Then, clean all the parts in the watch cleaning machine.

Assembly

Start with the main barrel and the wheel train.

Fit the separateĀ bridges/fingers of the wheel-train bridge.

Roamer MST 264

The main barrel, wheel train, and the wheel-train bridge reinstalled

Replace the barrel bridge, crown wheel, and the ratchet wheel.

Roamer MST 264

The barrel bridge, crown wheel, and the ratchet wheel refitted

Turn the movement around and start with the motion works and the keyless works.

After I reassembled the keyless works, it didn’t function well when I tested it.

Then I compared the movement with the illustration in the parts sheet.

Roamer MST 264

Please note the return bar

Roamer MST 264

The original parts sheet with a picture of the bottom plate

So…I had the return bar upside down. Stupid! Weird thing was that I didn’t have to use force to install it this way.

Normally, you’ll notice immediately when something isn’t right. It won’t fit or you have to use force.

I noticed nothing of the sort. It did function but it didn’t function like it should have.

Roamer MST 264

The top plate complete reinstalled. Now with the keyless works in the correct way šŸ˜‰

Flip the movement to the top plate and fit the pallets and the balance.

Roamer MST 264

The MST 264 purring like a kitty. The regulator index currently has a better position as well

Normally, I’d polish the crystal but it was too far gone so I simply fitted a new one.

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

Founder & editor of WahaWatches. I’ve been collecting watches for years. My favourite part is to pull them to bits.

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