Removing stem on caliber 3301

Frogman · Feb 6, 2022

Hi all,

I have some experience in vintage watchmaking, but I have an omega caliber 3301 that has some dust on the dial that id like to remove. I am having trouble removing the stem. Can anyone guide me as to the removal process, as it appears different from other non-chrono omegas that I have worked on.

thanks,
E

JimInOz · Feb 6, 2022

F Frogman
Hi all,

I have some experience in vintage watchmaking, but I have an omega caliber 3301 that has some dust on the dial that id like to remove. I am having trouble removing the stem. Can anyone guide me as to the removal process, as it appears different from other non-chrono omegas that I have worked on.

thanks,
E

I think you have to remove the chrono plate first, not sure though as I haven't seen a 3301 for a while and my memory is usually concerned with finding where I left my glasses/shoes/pants.

Archer · Feb 6, 2022

No need to remove anything to release the stem. It's a very standard screw as you would find on many vintage watches...right at the red arrow:

The rotor has been removed so you can see the screw easily in the photo, but it doesn't have to be removed - it can just be rotated to one side to access the screw. Like any watch with a screw for the detent, don't unscrew it any further than is needed to release the stem, or you will have a much bigger repair on your hands.

Cheers, Al

Frogman · Feb 6, 2022

Archer
No need to remove anything to release the stem. It's a very standard screw as you would find on many vintage watches...right at the red arrow:

The rotor has been removed so you can see the screw easily in the photo, but it doesn't have to be removed - it can just be rotated to one side to access the screw. Like any watch with a screw for the detent, don't unscrew it any further than is needed to release the stem, or you will have a much bigger repair on your hands.

Cheers, Al

Thank you so much. This worked perfectly!!

GreganT · May 22, 2025

Hi Guys. I know this is an old thread, but my issue pertains to this topic. Recently I had an issue where the stem would not go back into time-keeping mode, once pushed back in. Apon opening the watch, I observed that the screw discussed above was missing. I have sent the watch in for repair with a very experienced well know German watchmaker, who is telling me that this is a push in an release mechanism. I am concerned, as I can see the screw existes in these pictures, but I cannot fint this screw in the parts list for the 3301. (Cousins) I can see it in the schematics, but it is never listed or shown in the breakout diagrams. So confused. I thought the screw had fallen out, but it was not to be found in the watch or movement. The only way I could get the stem out was to push down insidee the hole where the screw was supposed to be, meaning the stem never released from the movement, even with the screw missing...any thoughts very welcome. Will chat to the watchmaker more today.

Archer · May 22, 2025

GreganT
I have sent the watch in for repair with a very experienced well know German watchmaker, who is telling me that this is a push in an release mechanism.

He's wrong...it's a screw.

GreganT
I can see it in the schematics, but it is never listed or shown in the breakout diagrams.

It's part number 72233036407 - not sure what you are looking at but it is clearly shown in the parts breakdown I'm looking at for the 3301.

GreganT
So confused. I thought the screw had fallen out, but it was not to be found in the watch or movement.

Not sure what is going on, but that screw can't really "fall out" as it's held in place by the barrel bridge. Meaning the barrel bridge would have to be removed for the screw to be removed. So unless the screw head has been sheared off by someone playing with it, then it cannot fall out.

GreganT · May 22, 2025

Thanks for clarifying, Archer. It's a great help realising that the scew could not have "fallen" out. There was no screw found in the case or movement anyway, which means it was missing from at least the last service 4 years ago. Yet, without the screw, the watch worked as intended in all that time, before having issues recently with the stem not setting back to timekeeping mode after pulling the crown out to set the time and date. I could also not release the stem from the movement without putting a small round pin-pusher down the (screw) hole and applying (as little as I could) pressure, which was the last straw, because the stem would not lock back into place, once re-inserted. I'm sure that all has a mechanical explaniation, and I wish my skill level was to the point of me being able to desassemble the movement myself to look, but alas my experience, confidence and skill level is not there yet.
Could something have been modified perhaps? It's all very strange to me. I did go and visit the watchmaker, who completed the service and the watch is performing as intended, still with no aforementioned screw in place, and a veteran watchmaker saying that what is there, is a push in setup...

Archer · May 22, 2025

GreganT
Could something have been modified perhaps? It's all very strange to me. I did go and visit the watchmaker, who completed the service and the watch is performing as intended, still with no aforementioned screw in place, and a veteran watchmaker saying that what is there, is a push in setup...

Are you sure this is a 3301 caliber?

I suppose it could be possible that someone modified the setting lever somehow to eliminate the screw, but I can’t imagine why anyone would do that instead of just getting the screw…

What is the reference number of the watch?

GreganT · May 23, 2025

Hi Archer. Pic Attached

GreganT · May 23, 2025

Hi Archer. Thanks. I looked at the schematics again, and with your parts reference can now clearly see how the orientation and shape of the screw means it would not be able to just fall out, and also how the screw is actually held in place by the screw collar, so that the screw itself does not screw out, but moves the the lever instead.

Archer · May 23, 2025

GreganT
Hi Archer. Thanks. I looked at the schematics again, and with your parts reference can now clearly see how the orientation and shape of the screw means it would not be able to just fall out, and also how the screw is actually held in place by the screw collar, so that the screw itself does not screw out, but moves the the lever instead.

Thanks for the photo - so this is a 25945200 Seamaster chrono. Just one thing that you should ask your watchmaker about...

The red arrow points to wear on the rotor. This means that the rotor is contacting something - in this case it would be the inner antimagnetic cover, and there is very likely a corresponding circular mark on the underside of the cover - it would look something like this:

This is a result of the bearing for the rotor being worn out. It allows too much lateral play and the rotor ends up scraping the inner cover - this can affect automatic winding performance, and also create debris inside the watch. Unfortunately due to the design of this family of movements, the only solution is to replace the part that the bearing is located in, which is the automatic winding bridge - this one is from a Cal. 3303 but gives you an idea:

He should get a new bridge from Omega for this to ensure a proper repair. Part number is 722330312050.

Cheers, Al

GreganT · May 23, 2025

Many, many thanks Al. I will chat to him about this!

Removing stem on caliber 3301

Frogman

JimInOz

Archer

Frogman

GreganT

Archer

GreganT

Archer

GreganT

GreganT

Archer

GreganT

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