Hello-Just received this Seamaster- and I am no expert-but it looks original....runs good ( yes I will get it serviced!) and rotor moves freely-but when back is snapped back tight-the rotor does not move as freely as when the back is off...I did replace the trashed crystal with a temporary generic...is the 2767 case correct for the watch? or is the replaced crystal possibly putting pressure on the movement and pushing it onto the inside back? Will a correct Omega crystal solve this? Any ideas or opinions? thanks

 

The crystal has nothing to do with it. The rotor bearings are worn, and the rotor is touching the case back when the back is snapped on. You can just see the contact scrape marks on the rotor and the inside of the back. This is by no means uncommon with these old bumper movements. With a screw back you can fit a thicker gasket to get you by temporarily, but a snap back leaves you no room for manoeuvre.

P.S. The 2767 case ref is correct. And a very nice example, by the way!

 

Thanks-how big of a deal is it to replace worn bearings during a regular service?

 

I've never had this done (yet!), so I would be as interested as you to know the answer to this question. The 28.10 mm series bumpers changed their rotor design when the 351 was introduced. On the early exposed spring versions the rotor bearing is bronze. These later ones (351, 354 etc) have a jewelled bearing for the rotor as you can see in your picture, so it is more likely to be the rotor axle that is worn rather than the bearing (or perhaps both). Replacing the jewel should be straight forward, but as the axle incorporates a geared segment I think it could be difficult to source?

 

I have had this done as a part of servicing a 352RG. Identical rotor design.
Parts must be found om ebay or similar as Omega does not sell these. I paid GBP 48 at ChronoPassion in France for the sleve and jewel. It works perfectly after this.
The full service blog can be found here: http://watchguy.co.uk/service-omega-seamaster-calibre-352-2/

 

thanks again...is it your opinion is there any other possible source of this problem? Is it possible that a complete overhaul without replacing parts would have any effect?

 

It is like a worn bushing on your car. Only when you replace it with a good one will the rattle and shake stop
A very easy job for a watchmaker while servicing the movement.

 

Thanks! do you know if these these rotor parts specific to chronometre 352 -354 etc...or are they interchangeable with non chronometre versions?

 

The parts should be fully interchangeable.
There are no differences in the winder parts.
Many of the parts are also the same on several calibers.