Omega 166.020 crystal replacement advice needed - Seamaster De Ville

Hi All,

I would just like to ask for some help regarding the replacement of the crystal for this reference. I have some experience as a hobbyist tinkerer with watches however, I have no previous experience with this unicoc case (yes, I know, I should start with something less valuably, haha).

Admittedly and embarrassingly, I attempted to do this on my own after spending a while investigating and trying to get it to work. It just wouldn't work. I was starting to get frustrated. I think we all know what happens when we get frustrated...not good! I completely shattered the crystal. Maybe I was using a dye that was too small compared to the size of the crystal? I should have stopped but I just wanted to get it done. This happened a few weeks back - now that it's been off my mind for a while and that I'm finally over the fact that I destroyed an original Omega crystal, I can finally bring myself to ask for some advice.

I know it would be best to have it taken to a watchmaker, but I would honestly like to learn how to do it for myself. I also like the sense of accomplishment that you get when you can repair something on your own!

The parts I have:
- Case ref. 166.020
- Part no. PZ 5072 (please advise if you believe this is not the correct part no.)

The equipment that I have:
- Bergeon crystal lift
- Caseback/Cyrstal press



The watch currently has a horrible generic crystal fitted. You may also see that the steel ring is not part of the crystal - it is currently sitting on the dial (removed when trying to fit the PZ 5072 of course). Interestingly, that silver ring is a complete circle unlike the tension ring. The PZ 5072 comes with its own tension ring which was giving me a hard time installing it.


And here's one for you all to laugh at! 😟🤔 Mistakes happen, but that's how we learn.

Sincerely appreciate all the help and advice from all. Look forward to reading your comments!

Best,
Chris

given the gorgeous pristine condition of your dial I would have a pro handle this job and simply get that sense of accomplishment with monkeying around on another watch. 😁

Hi Al,

Thanks for the info! Appreciate it.

Just double checked the part number and I can confirm it is the 063PZ5072 that I had used. I hope the spare I have is the same one.

I just couldn’t get it to press in 😕👎 The crystal goes in from the front, am I correct?

Thanks again,
Chris

Thanks @janice&fred It is in a very nice condition 😁 I would really want to give it a try myself. I had the entire dial and movement out of the case as a precautionary measure when I tried to fit the new crystal - I did foresee myself screwing up badly before I actually attempted.

Could this have been the reason why it wouldn’t work? Though I wouldn’t think it is the problem as the crystal wouldn’t fit into the bezel, never mind being pressed all the way to the back of the case and being crushed.

If I really can’t fit it on my second attempt, I will most likely take it to a reliable watchmaker who will try to extort all the money I have 🙁

Best,
Chris

I forgot to mention, I was applying quite a tremendous amount of pressure trying to press the crystal in. So much pressure that I was perplexed at how reluctant the crystal was to fit in.

To me it felt like I was using a lot more force than is required to fit such a crystal.

Hi!

I’m not quite sure what this means 👎 I was under the impression that the crystal (with tension ring) had to be pressed in from the front to fit on the bezel.

Are you suggesting the crystal to be installed from behind the bezel, and pressed outward? How would I go about using the crystal press with only the bezel? I hope I’m not talking gibberish, haha.

Thanks @X350 XJR !

Chris

Hi Chris,

Thanks for your input. I don’t expect you to be watchmakers, I never mentioned this.


I have considered it, yes. It is not as if I haven’t been doing it myself either. I have also invested on my time, tools, many watchmaker books, and browsing the web before posting here.


Let me tell you, I had carefully inspected the parts for hours, trying to figure it out. I thought I got it. Obviously I was wrong.

Thanks for your input.

Chris

I really do appreciate your advice @Archer and I have seen your many contributions on this forum.

My apologies if I have offended you. I did not say this as a generalising statement. I have been quoted £120 for a crystal replacement by the watchmaker. I hope you understand where I’m coming from.

I hope you accept my apology.

Best,
Chris

Hi Jens,

I hope you got your watch sorted out! What was wrong with your originally-installed crystal?

Best,
Chris

I have had a couple of Seamaster devilles and I have been able to squeeze the crystal back into place with my fingers. I also wiped any accumulated grime etc off with a microfibre swabs under the microscope. It brightens up the dial an awful lot.