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Omega 285

chadders1966

By chadders1966
in Watch Repairs Help & Advice

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chadders1966 WRT Addict

chadders1966

Posted
Posted

Hi

 

I'm in the process of stripping down my own Omega 285 for a service. Not something I've done before, and I'm trying to be careful :). The attached photos show a part that is puzzling me. Is the wheel permanently attached to the bridge, or is it removable? I don't want to just pull at it. Thanks

 

Stephen

 

post-373-0-98095800-1455445423_thumb.jpg

post-373-0-42884700-1455445432_thumb.jpg

Geo Distinguished Member

Geo

Posted
Posted

The top wheel should really have been pulled off before removing the bridge. There is a special Presto No3 puller for doing this that has two claws on one side, and one on the other.

Do not try to remove the wheel from the bridge without the bridge being on the movement!

post-124-0-86757400-1455446756_thumb.jpe

post-124-0-28327100-1455446805_thumb.jpe

post-124-0-27952800-1455446862_thumb.jpe

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Marc Distinguished Member

Marc

Posted
Posted

The wheel on top of the bridge is the indirect centre seconds wheel and it is a push fit onto the extended third wheel arbor which projects through the bridge.

 

It can (and indeed should) be removed to facilitate cleaning and oiling of the pivot but you must be careful. Being a push fit it just pulls off, however, the extended arbor is very delicate and any action that causes the wheel to cant or tip unevenly to one side or the other can very easily snap it.

 

You can get a puller specifically for the job which looks like a modified "Presto" type hands puller, another fairly safe approach is to use two single edged razor blades pushing in evenly on opposite sides to lift the wheel. Once there is sufficient clearance you can graduate to Stanley knife blades to complete the job.

 

Reassembly is best achieved using a staking tool, but if you don't have access to one then just careful even pressure.

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chadders1966 WRT Addict

chadders1966

Posted
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Posted

Thanks very much guys, I'm glad I asked now! It's a shame I can't find a detailed service sheet anywhere, there are a few things about this movement slightly different to what I am used to. So to remove this wheel I need to apply even pressure undeneath the top wheel, with the bridge firmly secured?

 

Stephen

chadders1966 WRT Addict

chadders1966

Posted
  • Author
Posted

It all went fine thanks, and it's back together now. The only problem is today I managed to lose not one but two parts! One of the cap jewels (not sure which one, or even if they are different) shot off into space. I do have spares, but I have no idea how thick the original was. Is there any way to find out, or do I just have to experiment?

As well as that the intermediate wheel has vanished - it was there as I put it in place. I briefly turned the movement to check on something and obviously it fell out. Can't find it anywhere - I think it's the largest piece I've lost so far! Fortunately the watch is mine, but it is very annoying. I can't find a reference to this part. Are intermediate wheels known as anything else? Thanks

Stephen

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