omega 920 winding stem

[gary17]

Hey

I am trying to remove the winding stem, but someone has put the wrong winding stem in. I have released the screw holding the stem but it wont move. I have tried a little force using the tweezers behind the crown but still no luck. Its also been oiled and it wont come out.

Has anyone any ideas before i will have to force  it out which i would prefer not to do.

cheers

gary

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[ITProDad]

Hey
I am trying to remove the winding stem, but someone has put the wrong winding stem in. I have released the screw holding the stem but it wont move. I have tried a little force using the tweezers behind the crown but still no luck. Its also been oiled and it wont come out.
Has anyone any ideas before i will have to force  it out which i would prefer not to do.
cheers
gary
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Pictures?


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[gary17]

Pics as requested

[oldhippy]

How do you know it is the wrong stem? From what I can see I suspect rust is preventing it from being removed. So as not to damage the movement, put penetrating oil on the stem and let it run into the keyless work. Have you tried to unscrew the button from the stem? 

[Nucejoe]

53 minutes ago, oldhippy said:

How do you know it is the wrong stem? From what I can see I suspect rust is preventing it from being removed. So as not to damage the movement, put penetrating oil on the stem and let it run into the keyless work. Have you tried to unscrew the button from the stem? 

   perfect.

[gary17]

Tried oil and WD40 no movement. 

You press the crown in. And the fingers can be set but will not wind. And definitely won't come out of movement. So I cannot get to keyless works. Crown won't come off either

Edited October 1, 2019 by gary17

[WatchMaker]

Is the stem/crown moving in and out? From the information given I'm assuming yes as you're implying the hands can be set ('crown out') but will not wind ('crown in'). In this case the keyless works aren't rusted solid and all that should be holding the stem in is the setting lever. Normally someone would only want to undo the setting lever screw far enough to allow the stem to pull out but in this case, since you'll be dismantling the watch anyway, then it doesn't matter how far you unscrew!

The screw on the 920 should not be 'captive' so should actually be removable in itself. So remove it; use tweezers or hold the movement upside down and gently tap; hopefully the screw should come out. This should free things enough so that setting lever is no longer holding the stem. If, once you've removed the screw, the stem will still not remove then it indicates the setting lever is somehow jammed; consider pushing a small screwdriver into the screw hole and gently pressing down on the lever whilst pulling the stem to see if that frees things. Good luck!

[Just as an aside since I'm replying ... I note you ask a lot of questions but I rarely see any 'thanks' and/or follow up on results! Things like that are important on a forum like this where people are taking the time to read your many requests for help and giving their advice for free ... or other people have the same questions but can't see if the advice was successful or not. Hopefully other contributors agree. ].

[gary17]

hey

I can only apologise.

I will of course remember to leave feed back in future.

thanks for the heads up.

The winding stem does not move in or out. It pushes the movement. When you hold the stem tight to the case you can adjust the hands. when you dont hold it next to the case there is nothing.It just freely turns. 

I have just removed the setting lever screw and prodded with a screw driver and nothing happening.

The watch is working, as is the chrono  push. How i don,t know. because you cannot wind it.

The only thing i can think of doing now is to snip the crown off and then i can at least get the movement out of the case and get at the keyless movement.

I cannot think of any other way.

Well i have sorted it DOH.

The stem has snapped.Got half with the crown the other half still in keyless part.

Thanks everyone who tried to assist.

Its appreciated.

cheers

gary

 

Edited October 1, 2019 by gary17

[gary17]

Hey

I was about to tackle keyless work following marks video.But my chronostop has a calender and is different from marks video watch. (see pics)

The slot on the right has a spring holding 2 pieces in place under the bridge.

Do i remove the bridge or the spring first?

I have only serviced or repaired old mechanical watches up to now and non with calenders or chronos before.

any one know were there is a video of a chronostop geneve with a calender.

or any other suggestions.

The keyless work that i can see is covered in a thick hard black substance and the setting lever is solid so eveyones advice seems spot on thanks. I just need to be able to get at it now

thanx gary

Edited October 1, 2019 by gary17

[WatchMaker]

Thanks Gary. 

At least you've managed to get the movement out which is good. I'll be very interested to see a pic of the keyless works when you get to them. The works can get grubby for sure but for the setting lever to be so jammed is unusual and what is this mystery hard black stuff!

A really good resource for various movement breakdowns is Christian Dannemann's WatchGuy website. If you do a web search for the term 'watchguy' and then the movement ID you're interested in he often comes up trumps.

So for your 920 look at https://watchguy.co.uk/cgi-bin/library?action=show_photos&wat_id=2542. In this case Christian has removed the spring first but actually you could have removed the retaining plate first. [For most movements you'll deal with springs are held captive by the plate and are not removable through the front like this 920. A top tip when starting out is therefore to take the plate off with the movement in a clear plastic bag. You can poke a screwdriver through the bag to undo the screws and this way if there is a spring under tension ready to make a bid for freedom you've trapped that sucker in the bag!].

Christian's other photos should hopefully help out but obviously come back if you run into difficulty. Certainly please come back with the keyless works pic so we can see this!

[gary17]

Hey

Thanks for the watch guy page it's helped me get this far. 

Stem still stuck in keyless works. 

[WatchMaker]

That looks like some nasty corrosion; the watch must have had water ingress at some stage. Fortunately it doesn't look like the moisture progressed beyond the keyless works as the rest of the movement looks okay.

If the broken stem is still rusted in position it might be best to strip the rest of the movement to just leave the base plate with the rusted-in stem (and what looks like the trapped or rusted-on winding pinion and clutch parts too) and then soak in a proper penetrating oil. Also called 'release agent' or 'liquid wrench' this stuff can be picked up relatively inexpensively from an auto store. 

Edited October 2, 2019 by WatchMaker

[watchweasol]

Hi Gary Looks decidedly rusty in there, been following this post and watchmakers advise has been spot on, nothing to add but follow the advise given and you will be ok.

[gary17]

Hey

Thanks for the advice. 

My problem now is I don't think I am capable of tackling the chrono strip down. 

It seems very complicated and as I have said I have only worked on simple straight forward watches. 

I was hoping just to repair the keyless works only. 

But I agree with the advice I have been given it needs a total strip down. 

I may have to put it on the back burner until I have a bit more experience. 

It's the springs and the complicated works of the chrono that worrying me. 

It's a watch I like so I don't want to wreck it. 

But I realise if I don't strip it and clean it the watch could still deteriated. 

Guess I have to make a decision. 

Thanks everyone anyway

Gary 

 

[ITProDad]

Hi Gary. I’ve been watching your updates. There is a very strong possibility there will be other contaminants inside the works of this piece in addition to the visible rust. If you can address the keyless works and get some semblance of performance out of it, that would be excellent.
If you cannot, the it is no longer a chronograph. It is an opportunity to learn and possibly restore it to being a chronograph. If you decide to tear it down, take pictures every step of the way. Then, if you are able to clean it an repair ir replace malfunctioning parts, you will be able to rebuild by going through the pictures in reverse order.
I don’t know what you are capable of doing. I’m merely suggesting that perhaps you are not fully aware as well.

Do keep us updated and geed luck!


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[gary17]

Hey

Yer you are right I will strip and photo it. 

It's no good the way it is now. 

Cheers

Gary

[Nucejoe]

Sorry for joining in late, I intended to join as gary requested, just red the post and forgot it, sorry sorry. Red a post of watchmaker, I agree, considering the rust that OH warned and that the piece is worth it, full strip down and checking all. 

Best 

 

[gary17]

hey

Got the courage up and i have removed the chrono works from the watch.

hope pics explain.

 

[gary17]

Hey 

Just got to get castle wheel and crown wheel from broken bent winding stem.

Just lost mainspring arbour DOH

How long should a mainspring be in a omega 920. Is there anywere i can check.

This mainspring seems very short?

regards

Edited October 2, 2019 by gary17

[gary17]

Hey

Can I use alum to remove the castle and crown wheel from the broken winder stem? 

Gary

[WatchMaker]

No. Alum is used to dissolve steel. It's useful where something is completely stuck within a different metal e.g. brass. If you use alum to try and remove your steel stem you'll damage those other steel parts too.

Where have you got to? Tell me if I'm wrong but in my mind's eye I see the stem rusted in position and, because of where it snapped, it has trapped the clutch (aka castle gear) and winding pinion (aka crown gear) ... which may have also rusted onto the stem. Did the soak-for-a-day-in-penetrating-oil not do anything? Mmm.

This being the case you might have to get gently medieval on that stem. If it were me I'd fashion a mini chisel from a suitably small screwdriver blade; a 1.20mm is probably about right. With a needle file I'd sharpen the blade and then cut a shallow 'V' in the blade simply to locate it properly. Place your improvised tool in the spot indicated ... which is about the weakest spot on the stem as it is where it narrows to locate into the baseplate. Strike down on the screwdriver vertically and that stem should snap. Be firm but gentle as you do not want to damage the baseplate or clutch; this weak part of the stem shouldn't take too much force to snap though.

With the stem now snapped where it goes into the baseplate is there enough play to get the other parts out and/or does the stem now remove completely (as it is likely it being rusted into the baseplate is the main problem here)?

Of course this method does mean you have the tip of the stem still rusted in position in your baseplate. But this is where you can possibly use that alum ... or very carefully drill it out. 

[gary17]

hey

I have the stem and 2 wheels out of the watch.

Problem is now trying to get them of the stem.

[watchweasol]

Hi  Gary  Its a bit of a mess.  Try soaking in wd40 for a time then using a staking block and fine punches drift the stem out. obviousy put the flat gear on the stake not the castle but be very careful.

 

[Nucejoe]

7 hours ago, gary17 said:

Hey

Can I use alum to remove the castle and crown wheel from the broken winder stem? 

Gary

I,d leave alum for the last resort. Soak longer, tap on the stem every few hours. If no luck, then use heat, device a soldering gun to touch the stem only, heat the stem and not the sliding nor winding pinon. Thermal expansion and contraction will break loose the rust bond between the stem and pinions.

Best

 

[gary17]

45 minutes ago, watchweasol said:

Yer

I have now broken a tooth off the crown wheel. Is it still worth trying to salvage it?

 

 

45 minutes ago, watchweasol said: