Before I answer the question below, if anyone tells you they are "Omega certified" they should have no issues getting these parts. My feeling is that the shops who said they could not get parts were either never certified to begin with, or may have been certified in some manner in the past, but no longer are. All the parts needed for the 55X and 56X series movements can be ordered from Omega.
The rotors (oscillating weights) on these calibers use a plain bearing, not a rolling element bearing like a ball bearing. So in this case there is a hardened steel axle running in a softer bushing that has a gear attached to it - this is called the pinion. When the pinion gets worn, it allows the rotor to flop around, and if it's bad enough it will scrape on the plates of the movement and possibly on the inside of the case back. Here is a video showing the play in one of these with a worn pinion:
Fixing this is essential, because if you don't the rotor scraping on the plates or case back will cause damage, and also spread particles through the movement. Here is one that was scraping on the case back, and you can see a small section of wear at the high spot at the red arrow:
And here you can see where is was scraping the inside of the case back:
This happens with ball bearing as well, so here worn spots on the high points of the rotor finish:
Closer look:
And wear on the inside of the inner anti-magnetic cover in this case, rather than the case back:
New pinions are available from Omega, and changing them takes only a couple of minutes. Here is the process - start by pressing the old pinion out using the Horia tool:
You can see the teeth on the pinion on the underside of the rotor:
Pressing it out:
Old pinion removed:
New pinion:
New pinion is pressed into the rotor:
Not quite done yet - the inside diameter of the pinion is left intentionally undersized, so it must be reamed to fit the axle:
I do this very often, so I have a reamer set-up in a staking set base all the time specifically for this job. The reamer is oiled, and then brought down through the pinion:
After reaming the pinion is tested with the axle - if needed there is a second larger reamer that can be used to enlarge the hole another .001 mm:
The parts are then cleaned:
And the automatic module can be fully assembled:
So this illustrates the repair - again it only takes a few minutes in real time.
Cheers, Al
Click to expand...