ETA 2472 - how to tackle this crown and stem?

[Michalzeszen]

Hi there!

I have been servicing an old Technos Star Chief from the 70s, and so far so good, except for the crown and stem.

This is only my 4th or 5th watch service after a year of fiddling with cheap movements, and I'm having a hard time understanding this seting mechanism.

 

1. What is is called?

2. How do I assemble it?

3. Can we confirm all is there?

ps.: bonus pics demonstrating how it was bought and how it is going.

 

[Klassiker]

It's a so-called split stem. I'm guessing the spring is for the screw-down crown operation. I don't think I've ever seen both features together before, but it looks complete. If I'm right, the crown will have an inner thread and the tube a matching external thread. Replace the seals if you want it to be watertight.

If you can compress the spring far enough, slide the two parts of the stem together sideways. If that doesn't work, you should be able to push them back together end to end, the opposite of how you pulled them apart. 

[Nucejoe]

2 hours ago, Klassiker said:

 slide the two parts of the stem together sideways. 

 

 

[Michalzeszen]

17 hours ago, Klassiker said:

If that doesn't work, you should be able to push them back together end to end, the opposite of how you pulled them apart. 

I had a feeling the worst would happen, and it did. The smallest pressure applied to the crown broke one side of its little leg.

I think I'll replace it with a traditional system if possible.

This, I believe. I'm shocked at how expensive the parts for this model are.

[RichardHarris123]

Since the back can be removed, I  see no reason for a split stem. 

[AndyGSi]

The one on eBay doesn't look like a screw down crown. Is the original?

 

[Klassiker]

Richard and Andy both make very important observations, so let's take a step back and see what we are dealing with.

Does the crown tube in the case have a thread on it?

How did you remove the stem? Do you have a photo of the movement in the case?

You might be able to remove the female part of the split stem and reuse the existing crown. Can you see a thread?

There are one-piece stems available for the 2472 for reasonable prices. The split stems I found on ebay for the 2472 are a little more expensive, but have the male and female parts the opposite way round.

[Michalzeszen]

OK. Little panic, but I'm composed now. haha

I need some support on this one, and you guys immediately noticed that. Thank you!

To help us navigate the situation, I recorded a video of the case and crown:

https://youtu.be/tfTLZrLiaqg?si=hIW8Jbmp1DPb9fZC

The measuremen

3 hours ago, Klassiker said:

Does the crown tube in the case have a thread on it?

 

Yes, it does.

3 hours ago, Klassiker said:

How did you remove the stem?

There was water damage, and the two pieces (stem and crown) split up when I removed the crown. I didn't have a chance to see the assembled mechanism, but this eBay ad has the same assembly with adequate pictures.

3 hours ago, Klassiker said:

You might be able to remove the female part of the split stem and reuse the existing crown. Can you see a thread?

I'll try that. Quite afraid of breaking it, thought.

Edited 1 hour ago by Michalzeszen

[AndyGSi]

So the eBay crown won't work with your case.

It's looking like your options are going to be limited with this one.

Edit

Just found this so looks like you can remove the stem part from
the crown but what you replace it with is another question.

Edited 31 minutes ago by AndyGSi

[Michalzeszen]

You guys were correct, I can reuse the crown. Now it is a matter of finding the small split steam on eBay!

3 minutes ago, AndyGSi said:

the crown but what you replace it with is another question.

 

Yep, just realized this as well. Now it is a matter of finding the new piece, which will most certainly be a pain