Repair: Omega Railmaster co-axial calibre 2403

You got to admit it – this is a great looking watch, and it has the Omega co-axial calibre 2403 movement in it. It’s the A series, which beats at 28,800.

Dave has sent this one in, as the watch stops randomly, and only starts up with a bit of shaking, only to stop again soon after.

To have a first glance, I open up the watch and have a peek…

One of the case screws has come loose, and the clamp and screw are rattling around.

There are some scratches, as the case clamp and screw got caught by the rotor. Not very visible, but they prove that the clamp and screw were moving around and not stuck in one position. So the problems the watch has had are easily explained.

And there is the case clamp.

As the watch is performing well on the timegrapher, this is where I will stop. I’m putting the clamp and screw back, clean the gasket, put some silicone grease on it, and close the case again.

Now for a couple of days on the bench, to see if this has resolved our problem.


The watch is doing well, performs great on the timegrapher, and the loose parts are the most likely cause of the problems.

Wit the seal cleaned and greased with KT-22, I can put the case back back on.

The bracelet gets an ultrasonic bath, and we are ready to roll.

Ready to ship back.


3 thoughts on “Repair: Omega Railmaster co-axial calibre 2403

  1. Pingback: DJII or AT? - Page 4

  2. Nice write-up! I bet you love it when it’s an easy fix. The watchmaker I used to work with often told me of some jobs that were a hassle to deal with.

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