Hi-New to the forum, and to Omega. Just bought a Seamaster Aqua Terra GMT chrono. I am not sure if there may be a problem with the crown. When screwing it down, it does not stop turning, unlike my Rolexes which "lock" when they screw down. Is this normal or a problem? Thanks!

 

I just did, in a separate thread.

 

Sounds like the sleeve (or whatever they call that part the fits into the case that's threaded to accept the crown) is loose. Something isn't right.

 

That happened to my PO once. The crown came loose from the stem. Take it to your AD for them to repair. It should not cost much.

 

That would be the case tube. Probably stripped threads on the tube or the crown, and both should be replaced. It's a bit of a job to do. Movement removed from case, bezel removed, crystal removed (as the case will be heated), heat case tube and unscrew, then clean the case, get new tube, Loctite in place, let cure, then reassemble everything.

Cheers, Al

 

Bingo. Thanks Al!

 

Is the case tube on a sea master bond 2531.8 pressfit or screw in?

 

Could be either depending on the age.

 

manufactured mid 2002 sold dec 2002 2531.8

 

My watchmaker says mine is push fit and iy has popped out twice on screwing down crown. What is the procedure to fit one and make sure it stays. Surely some like that a precision fit that needs to bewater tight cant be hammered in?

 

Is he installing new tubes? From the sounds if I doubt he is. There are special tools for pressing case tubes in and out that I would expect your watchmaker should already have. Omega also calls for using Loctite retaining compound (638) for friction fit case parts, such as case tube, correctors, press fitted pushers, etc. It's not about hammering it in...

 

Why heating? Different metals and expansion coefficients in case and tube?

 

To break the bond of the Loctite installed at the factory....

 

He is installing a new tube, the previous one I wanted replaced due to retaining long term water tightness. The pressfit system sounds like shite to me. The thing is the when sent back to me the crown didn't clear the screw threads on position 1 and needed to be reversed and then wound clockwise one rev at a time so I'm thinking the stem was too long some new parts used like crown also so maybe defective from omega ot not compatible or the tube not in enough. What about heating the case and pushing the loctiyed 638 stem in? How is it the case is water resistant to 300m with a pressfit tube? This has to withstand the twisting of the screwdown crown without twisting itself so I'm thinking its cold welded ie metal to metal with no loctite just heated and the ice chilled casetube driven in. Are you sure omega recommend the 638 on a seamaster? What about just heating the case and pushing the frozen tube it? If 638 is used surely it will not cold weld? This may be ok for most watches but a screwdown seamaster?

 

If done properly, it seals just fine. There is no need to heat the case, freeze the tube, or do any other crazy idea. Just press the tube in with 638 retaining compound, and it will seal fine despite your belief to the contrary. And yes, I'm sure of the procedure...

If your watchmaker changed the tube and the crown, he needs to make sure he has the correct crown for that specific tube - the crown for the screw in tube is a different part number than the crown for the press fit tube.

Cheers, Al

 

Hey right ok, Il copy this thread to him. He works on many watches and each one has its peculiarities. Omega is a company with a million different parts. What ever happened to the business/ engineering principle of standardisation...

 

Thanks once again. not good they used such a system. Obviously the screw in case tube is a later incarnation? By screwing something in especially something with stretch the clamping force will hold it very securely.
The 638 I was looking is a kind of reversible glue. How long to leave it set ?
Who would believe a 300m watch relies on this set up?

 

I do - it works just fine mate. I don't know why you are stressing about this so much - it is a common method of securing case tubes. If you need to know how to use the Loctite products, read the manuals...there are cure time charts that relate to temperature in there that can guide you or your watchmaker (who I'm sure must already know all this...).

By the way, the screw in tube uses Loctite as well, but thread locking compound as I have already stated elsewhere in this thread. Again this is per Omega procedures...same goes for any screw in case tube, screw in HEV, screw in pushers, etc.