I recently picked up a Wittnauer from the 60s and the movement appears to be a bit loose in the case. The original movement ring is present and everything looks in order. Could it be that the crystal should have retaining ring? How would one know if the crystal for a particular should have one?

 

Top loader?
Let's see a pic.

 

Exactly the one @dougiedude was selling here https://omegaforums.net/threads/60’s-wittnauer-sunburst-auto-now-399.90281/

 

Movements loaded from the back are kept tight from the rear. Either screws / clips that hold the movement in place or the metal movement retainer itself against the case back.
Something like this:


Or this:

 

Thanks for the input, @redpermit. The movement retainer is there. No gasket on the case back, though. Could the lack of the rubber gasket be the reason for the slight looseness?

 

This needs

Needs to be here

 

Could also be missing a wavy spring washer that applies pressure from the caseback to the outer ring.

 

But the little tab would attach to the movement ring, not the actual case. Other examples I've seen of the same movement don't have these tabs either:

 

Lack of a gasket should not matter. In fact, it should be more tight. I have seen some Bulova's that the gasket is an integral part of the movement seal against the case.
YES! The wavy spring that goes inside the case back. Like this:

 

Yes! I can see it in this example:

 

You guys are awesome. Ok, so my wavy spring is missing. What's the move? Can I replace this?

 

I don't see these as generic, sized replacement parts on watch part websites. It's off to ebay, I guess...i see some casebacks there with the spring.

 

Where are you located? If you are in the US, I can drop one in an envelope. Just need the correct outer diameter.

 

Terrific! PM sent.

 

Old thread, I know... Is there a source for these wave springs online? My google-fu is failing me. I can find a ton of 30mm wave springs but the are all like 17mm inside diameter and this looks more like 28mm inside.

 

Do you need one? Can you give me the dimensions?

 

Based on what I can tell by my trusty calipers (not very trusty) the outside diameter should be 30mm and inside around 28mm This is measuring right to the inside edge of the case back.

 

Do you have a pic of your old one? How do you know it's missing?

 

I find that cases which require a crystal with a reflector have a crystal opening that has the top lip of the opening rounded, rather than sharp. Crystals with a reflector are pressed in, and a case with a sharp edge makes getting a tight fitting crystal difficult. The crystal will snag on the sharp edge. With a rounded lip, the crystal will be easier to fit, and a tighter fit is possible. The seat for the crystal on a watch that uses a reflector crystal is often a bit wider than the seat of one that uses a regular crystal.

 

it's not for the crystal, it's for the movement/case. I don't have the old one. I haven't actually worn the watch in a long time. i took the back off a few years ago to take a picture and after that, the movement was loose. I must have lost the spring at that time.
I have pictures of the case back and movement in this thread. https://omegaforums.net/threads/my-seamaster-503-what-can-you-tell-me.12254/