Omega Seamaster 300 Case Tube question (ref 2551.80)

brandon640
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Evening Omega Forums,

I had just received my watch back (Ref 2551.80) from Omega's service and noticed that the crown tube does not have external threads on them.

The crown still screws in though so I'm assuming the threads are on the inside of the tube. However, when digging out the old crown tube from the bag of parts, I noticed that it was threaded. Is it standard practice to replace a threaded tube with what I presume looks like a press fitted one?

Would love some education! Thank you

IMG_6438.webp IMG_6439.webp
 
Archer
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The tube you show in the second photo is not the case tube for the crown. It is the tube for the HEV.

The case tube for the crown always had internal threads…
 
brandon640
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Archer Archer
The tube you show in the second photo is not the case tube for the crown. It is the tube for the HEV.

The case tube for the crown always had internal threads…
Thank you Archer for the knowledge! I guess I havent noticed that before
 
Archer
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pizzahotline pizzahotline
Hey guys, I'm trying to work this out with my titanium 2231.50 and what crown tube I need to find to replace it but there seems to be mixed information online. I can't work out wether the crown tube is pressed or threaded on this watch. Is there any way you could shed some light on this?

i found this part at cousins
https://www.cousinsuk.com/sku/details/omega-case-parts-search/x22990
There are 2 different cases used for this watch reference...

168.1623 and 168.1640 - they both use the same case tube, which is 090ST1232

I am 99% sure this is a threaded case tube, so it screws into the case - that is the best case scenario for a DIY project. To be sure, you can open the case back and do what is needed to see the inside of the case tube - you should be able to see from the inside of the case that the hole is threaded.
 
pizzahotline
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Archer Archer
There are 2 different cases used for this watch reference...

168.1623 and 168.1640 - they both use the same case tube, which is 090ST1232

I am 99% sure this is a threaded case tube, so it screws into the case - that is the best case scenario for a DIY project. To be sure, you can open the case back and do what is needed to see the inside of the case tube - you should be able to see from the inside of the case that the hole is threaded.
Awesome! Thanks for the knowledge. I'll go inside and see what's in there. It seems some of these aluminium bezel era seamssters use friction fit tubes and others use screw fit. The tubes often seem to go before the crown does, in my experience.

I'll be back with some pics! Cheers
 
Archer
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pizzahotline pizzahotline
Awesome! Thanks for the knowledge. I'll go inside and see what's in there. It seems some of these aluminium bezel era seamssters use friction fit tubes and others use screw fit. The tubes often seem to go before the crown does, in my experience.

I'll be back with some pics! Cheers
I would suggest replacing both whenever the threads are damaged...
 
pizzahotline
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Hey! I've finally been inside the watch and had a look. To me it's not so clear that it's threaded or a push fit. I took some pics, what's your opinion? Apologies, they aren't so clear

IMG_20250619_092445880.webp IMG_20250619_092453856.webp IMG_20250619_092430560 copy.webp
 
Archer
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Need a view of the tube from inside the case...
 
pizzahotline
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Ok, a month later I'm back! Life's been getting in the way of my hobbies 😀 Here's some pics of the inside of the case. It's really hard for me to work out if it's threaded or push fit but i'm sure you'll know. I also have a 2255.80 with a very good condition tube and crown on it so I was able to do a swap of the crowns between both watches and have sadly concluded that the titanium 2231.50's crown and tube both need replacing. It's a bummer as the titanium crowns are rare and expensive. However, I believe the tubes are cheap and plentiful, right?

Thanks for the help!

IMG_20250717_200929695.webp IMG_20250717_200850179.webp
 
JimInOz
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Based on the second photo I'd say the tube is a press fit.
 
pizzahotline
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JimInOz JimInOz
Based on the second photo I'd say the tube is a press fit.
Thanks so much! yes i'd agree. I'm going to get the part and try the repair. I've changed tubes in rolexes before but never on a seamaster.

I'm thinking..

Remove bezel and movement, heat the tube with a heat gun a bit. Pull with small pliars and twist. Should it pop off? Or, would it be better to use an EZ out tool?

I see cousins has the part but they have it restricted, annoyingly. Anyone know where to get it?

Would this be the correct way to go about it?
 
Archer
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pizzahotline pizzahotline
Thanks so much! yes i'd agree. I'm going to get the part and try the repair. I've changed tubes in rolexes before but never on a seamaster.

I'm thinking..

Remove bezel and movement, heat the tube with a heat gun a bit. Pull with small pliars and twist. Should it pop off? Or, would it be better to use an EZ out tool?

I see cousins has the part but they have it restricted, annoyingly. Anyone know where to get it?

Would this be the correct way to go about it?
Yes, it's definitely a press fitted version, and these can be very problematic to remove. This is nothing like removing a Rolex case tube.

Please look at this thread:

https://omegaforums.net/threads/basic-watchmaking-tips-changing-case-components.155881/ Cover Image
Thread 'Basic watchmaking tips - changing case components' ·
This is #11 in my series of basic watchmaking tips.

This thread is the result of a direct request made to cover replacement of case tubes, but I will also include some other common replacement...
Archer ·

Pliers are not a good idea. As the thread shows, you will need to apply heat so it's pretty standard practice to remove the crystal and crystal seal - you could leave it but the heat may damage the seal and possibly the crystal. You need to heat the case very well, then use the easy out style tool to remove it. Even doing that, you risk having the tube snap off inside the case, so be prepared for that to happen.

Cousins lost the ability (along with all the other watch parts stores) to order Omega parts 10 years ago - Omega still sells parts, but only directly to watchmakers, so they cut out the middle men. The part is not restricted by Cousins, and honestly their use of that word causes confusion all the time. They simply do not have the part to sell to you.
 
pizzahotline
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Archer Archer
Yes, it's definitely a press fitted version, and these can be very problematic to remove. This is nothing like removing a Rolex case tube.

Please look at this thread:

https://omegaforums.net/threads/basic-watchmaking-tips-changing-case-components.155881/ Cover Image
Thread 'Basic watchmaking tips - changing case components' ·
This is #11 in my series of basic watchmaking tips.

This thread is the result of a direct request made to cover replacement of case tubes, but I will also include some other common replacement...
Archer ·

Pliers are not a good idea. As the thread shows, you will need to apply heat so it's pretty standard practice to remove the crystal and crystal seal - you could leave it but the heat may damage the seal and possibly the crystal. You need to heat the case very well, then use the easy out style tool to remove it. Even doing that, you risk having the tube snap off inside the case, so be prepared for that to happen.

Cousins lost the ability (along with all the other watch parts stores) to order Omega parts 10 years ago - Omega still sells parts, but only directly to watchmakers, so they cut out the middle men. The part is not restricted by Cousins, and honestly their use of that word causes confusion all the time. They simply do not have the part to sell to you.
Thanks for the info! After reading that I'm more enclined to take it to a watch maker and get all the gaskets changed and pressure testedwhile i'm at it. Thanks!
 
Archer
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pizzahotline pizzahotline
@Archer Sorry to bother again but what was the part number for the press fitted tube for this model? Thanks.
There are at least 3 different watches mentioned in this thread, so what specifically are you asking about?
 
pizzahotline
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The push fit case tube for the titanium 2231.50. The case I sent photos of the inside case tube. You said it's defiantley a push fit. Just double checking it's a push and not a screw? the tubes aren't too expensive but the titanium crown is a different story sigh
 
Archer
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090ST1232 - this is a threaded tube but your watch appears to have a press fitted tube, so something is odd here.

Normally with a threaded tube, there is a through hole and threads all the way through the case, not the sort of partially blind hole you have on your case, so not sure what to tell you. Maybe they do things differently with the Ti cases? You will only know for sure when you get the old tube removed.
 
pizzahotline
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Okay this is very curious indeed! I read your very good instructional about tube removal and saw a hex shape on the inside of an omega tube you had. Is it possible mine has that if I remove and check? Sureley that will tell us if it's threaded or not?
 
pizzahotline
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What was the press fit part number? If I can find them for a decent price I'll order both
 
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