ETA 2472 - Disassembling the automatic device

[VWatchie]

If you’re like me, taking apart you first ETA calibre 2472 and feeling somewhat intimidated after having removed the case back lid looking down on the automatic works, then you will likely appreciate this post.

By the way, except for the oscillating weight itself, the automatic winding device is identical for the following calibres:
ETA 2450, ETA 2451, ETA 2452, ETA 2453, ETA 2454, ETA 2472, and ETA 2474.

My only other experience of ETA’s automatic winding devices comes from calibre 2824-2. So, looking down on the oscillating weight of the ETA 2472 and not seeing a screw holding it attached to the automatic device framework, made me think the parts had somehow been riveted together and probably were inseparable. Having removed and looked at the back of the automatic device framework I could see that the oscillating weight was indeed attached with a screw or at least something that reminded me of a screw. Its slot was very thin, and it sat in a large jewel! No way I was going to try to remove it without knowing for sure it could be done and how it should be done, especially as this watch wasn’t mine but my brother’s who’d trusted it to me for an overhaul.

My first thought then was to try to remove all wheels without touching the oscillating weight. After having looked at the device for a good long while, I realized I wouldn’t be able to remove a single wheel before separating the oscillating weight from the framework. So, I decided to be patient (hardest part of watch repairing), put the parts away for now and research the Internet. I Googled “eta 2472 how to remove oscillating weight”. The first hit was “Untitled - OM-Mechanics”, a PDF document. Well, I wasn’t feeling very optimistic but lo and behold, there it was, in full detail!

Anyway, the PDF is pretty poorly scanned, and it isn’t all that easy to read the part numbers, so I decided to make my own picture guide for disassembling the automatic device of this ETA calibre 2472, and that’s what follows next:

(Eventually, I’ll publish a complete ETA calibre 2472 service picture walkthrough. If interested, you’ll find a link to it in a future post in this thread.)

 

[Nucejoe]

Shouldn,t the two screws 51.134  come in darker color( gun metal)?

I am not sure but wasn,t there a polymer washer on the screw 51.498?   Do you find it on pdf?

[VWatchie]

2 hours ago, Nucejoe said:

Shouldn,t the two screws 51.134  come in darker color( gun metal)?

I am not sure but wasn,t there a polymer washer on the screw 51.498?   Do you find it on pdf?

I don't think so. They do on ETA calibre 2824-2, but not on calibre 2472 (obviously!?).

No, and no!

[nickelsilver]

Yes those auto systems are quite different if you're used to 2824/2892 stuff. Amazingly robust though, I rarely need to do more than clean them. The date mechanisms from that era will really throw you for a loop, but generally instantaneous change and again they work and work and work. Good to take photos as they can be unintuitive in function.

[anilv]

If there is excessive up and down play in the rotor you need to replace 51-498 and the gear which is a press fit into the rotor.

Bodge alert!! You can also address this problem to some extent by reducing the height of this post circled below. Only a little bit mind or you risk the rotor hitting the main-plate. If this happens you will need to remove some metal from the bottom of the rotor, usually the edge but in some cases even on the inner portions.

Anilv

[anilv]

To add to my post above, if you have tools which can cut the correct angle on the bottom of the automatic bridge this will also close up the clearance, in fact this is better but acheiving the correct angle is crucial.

Anilv

edit.. just realised yours has a jeweled hole.

Edited August 27, 2019 by anilv

[HSL]

VWAtchie Must say very nice work as usuall, a real treat, keep up this good work!

Edited August 27, 2019 by HSL

[Colditz]

I have just finished a clean and rebuild of a 2472. I needed to change the calendar date spring which is U shaped. The watch had not run for over 20years and is now keeping reasonable time. The calendar date wheel sometimes only flicks half way between dates. A gentle knock will flip the ring to the correct position. I have checked  the spring dims and all seems okay. Any advice would be very welcome. Its a great watch and good to have in my collection.

[jdm]

6 hours ago, Colditz said:

The calendar date wheel sometimes only flicks half way between dates.

Check date ring teeth and date wheel finger for wear. Problem can be there, not with the spring.

 

[nickelsilver]

You must lubricate the jumper for the date disk. Almost anything will do, 8200, 8300, Jismaa, D5, HP-whaterver, your choice. Put a bit, advance 5 days, a bit, 6 times. Can make all the difference in the world. Of course also the pivot point of the jumper and the contact point of spring on the jumper.

It can work fine after cleaning with no lube then get pissy a few days later.

It may be that the spring is to weak to handle decades of wear, or there is damage to the disc teeth as JDM said (this does happen, burrs develop and drag). Try the lube and see how it goes.

[VWatchie]

I've now completed disassembling my ETA calibre 2472 and made a similar picture guide for how to disassemble the date mechanism; 

ETA 2472 - Disassembling the date mechanism

[VWatchie]

So, I finally finished my picture service walkthrough for this ETA calibre 2472. Here it is!