ETA cal. 2472 problems with setting lever and screw

[VWatchie]

I’m having serious problems removing and replacing the stem on this ETA 2472 that I’m servicing.

The only way I can remove the stem is by unscrewing the setting lever screw completely. Of course, this makes it impossible to replace the stem. I’ve been trying to unscrew in extremely small steps while trying to remove the stem by gently, and sometimes forcefully,  shaking/moving the stem in all horizontal directions while pulling it out, but it just won’t come loose. That is until the screw detaches from the setting lever.

I’ve also tried to first reattach the screw to the setting lever and then later put the stem back in, but this fails too. In this case, the setting lever is just hanging on to the last half thread of the screw but when putting the stem back in it probably moves the screw a bit and the setting lever comes loose again.

It’s an understatement to say that this has been extremely patience-testing. Having removed large parts of the date complication for the fourth time to reach the keyless works, I felt 100 % stuck.
I wonder, is this a design flaw, are my parts somehow broken or faulty, and more than anything, what could be a solution?
 

[rogart63]

Think i have some 2472 parts . Can have a look . Maybe the threads ar worn in the setting lever. They look a little short? 

[VWatchie]

11 minutes ago, rogart63 said:

Think i have some 2472 parts . Can have a look . Maybe the threads ar worn in the setting lever. They look a little short? 

Thanks, and yes, that could very well be the problem! The design definitely seems to leave no room for imperfections! However, I'm happy to say that I just came up with a solution. I'm not a technical guy so I really, truly surprised myself (än är inte undrens tid förbi ). I realized that the case was big enough to insert the movement into the case with the stem attached to the movement, crown unscrewed of course, and then hold the stem with pliers inside the case while screwing back the crown from the outside of the case.

[Nucejoe]

Good approach. 

I have made a habbit of checking set mech with just the mainplate and stem, fixing faults, rinse and start assembly with stem attached.  I feel more direct control over/ much improved stem installation and results.

Good percentage of postings for help are about stem issues, most of which will surprisingly be eliminated if we start assembly with " stem issues solved" approach.

 

[VWatchie]

Thanks, Nucejoe! I usually do the keyless works pretty late in my assembly process (train wheels, barrel, bridges, motion work, keyless work, date complication if any, and finally escapement and balance). However, reading ETAs tech sheets it would seem they usually start the assembly process with the keyless works (at least for the 2824-2). Maybe there's a good reason for it!?

[watchweasol]

Hi Watchie  Looking at the setting lever I    should say the threaded hole is worn out and not giving the right drive when unscrewing there for best bet is to replace the pair as suggested.

[stevew]

I suggest doing the keyless works firsr. I have done some after, but one rather annoying watch, was a complete !! Had to re-dissaemble and do the keyless works first. We learn by our mistakes.

[watchweasol]

Hi Watchie  As above I usually start with the keyless work and work my way back to the balance. I think it all depends on the construction of the timepiece and your own preference.  

[VWatchie]

On 9/21/2019 at 10:21 PM, watchweasol said:

Hi Watchie  As above I usually start with the keyless work and work my way back to the balance. I think it all depends on the construction of the timepiece and your own preference.  

If possible I try to follow the assembly process as taught at watchrepairlessons.com (Level 2: Maintenance servicing). I.e., I assemble the keyless works just before the pallets and balance. I never really thought about why this is a "recommended practice" in the course. At first I thought it might have something to do with facilitating testing the free running of the train wheels, but this isn't a problem as long as we haven't installed the crown wheel and the click works on the barrel bridge I suppose. Another reason could be that the barrel bridge usually supports the clutch and winding pinion while assembling those parts. Well, I've strayed at bit from the topic of this thread, but nevertheless, why would it be a good or bad idea to begin with the keyless works?

[VWatchie]

Well, I have finally found the "true source of the problem", and I feel equally elated  and embarrassed 

The problem is that I replaced the setting lever screw after I replaced the barrel bridge, when in fact the setting lever screw must be replaced before the barrel bridge. Doing it in the wrong order "works" but it will make the oscillating weight slightly foul the head of the screw and it will make it impossible to remove the stem without the setting lever detaching from the setting lever screw.

This mistake I won't be doing again!