ETA 2892A2 - Keyless mechanism

[Rafael]

Hi! 
 
I have a weird problem.

I got an ETA 2892A2 to try and fix. It was an easy fix since the mainspring was broken. Replaced mainspring, put it all together and it worked great. After refitting the hands, I noticed something “slipping” in the gears. So I removed the dial again and opened the keyless work cover to try and see what’s the problem (which I didn’t open in the first place since this, as mentioned, was a mainspring replacement job).
 

Anyway, saw that the setting wheel does not properly engaging with the minute wheel so I disassembled everything and then put it back together but to no avail. Tried it again like 10 more times, including using the tech sheet and Mark’s video to see if i’m missing something but everything was in order. Checked to see if any of the wheels is broken or worn out but that’s not the case either and now i’m stuck. Everything works great separately but when putting it together the setting wheel just doesn’t properly interact.

Attaching some pics prior to disassembly. Note that there’s no date parts as this is part if a Mont Blanc watch which has a set of other functions under the dial in a separate mechanism. 
 

Any ideas as to what is the problem/fix would be much appreciated.

 

Rafael

[watchweasol]

Hi You say its "slipping" what exactly is slipping .and whats the problem it exibits.  The canon pinion with driving gear is known to be a problem area.  which tech sheet have you got. 

[Rafael]

20 minutes ago, watchweasol said:

Hi You say its "slipping" what exactly is slipping .and whats the problem it exibits.  The canon pinion with driving gear is known to be a problem area.  which tech sheet have you got. 

Hi Watchweasol, “slipping” means that it’s only partially engaging. Turns the minute wheel a bit (or not at all) and then “screeches” (like barely touches it and engages poorly). The funny thing is that if I try and turn in counter clockwise it turn better most of the times. 
 

As for the tech sheet, I have the one attached below.

14_ETA 2892.A2 2016 Version2.pdf

[clockboy]

It looks like all is engaged correctly therefore I would say the cannon pinion assembly (wheel) is slipping and will need replacing as this style can not be tightened. You will need to take measurements as there are 4 different possible heights.

https://www.cousinsuk.com/category/filter/eta-esa-movement-parts

[watchweasol]

Hi  Thats the best sheet so thats ok , as clockboy said and I mentioned before the canon pinion is the most likley culprit.  Take measurements of the old one before ordering .

[Nucejoe]

 Is the setting wheel on this tapered at one end?  The side thats suppose  to engage with sliding pinion.  

Do you feel the keyless FULLY change from wind to set position.

 

[Rafael]

9 minutes ago, Nucejoe said:

 Is the setting wheel on this tapered at one end?  The side thats suppose  to engage with sliding pinion.  

Do you feel the keyless FULLY change from wind to set position.

 

Yep, feels and looks like it’s changing fully and both sides are the same.

Edited August 23, 2021 by Rafael

[Rafael]

1 hour ago, clockboy said:

It looks like all is engaged correctly therefore I would say the cannon pinion assembly (wheel) is slipping and will need replacing as this style can not be tightened. You will need to take measurements as there are 4 different possible heights.

https://www.cousinsuk.com/category/filter/eta-esa-movement-parts

Thanks Clockboy, I’ll try later today to assemble it without the cannon pinion to see if this is indeed the problem but it feels and looks like something is off in the setting wheel since I can hear it not properly engaging (like its grinding with the minute wheel).

[jdm]

Just now, Rafael said:

Yep, feels and looks like it’s changing fully. 

I believe Nucejoe is on the right track. Somehow the sliding pinion or the rocker bar do not push all the way in the setting wheel, or they move back when turning the crown. You can take some pictures from straight above and these should show how the gears mesh. 

[Rafael]

17 minutes ago, jdm said:

I believe Nucejoe is on the right track. Somehow the sliding pinion or the rocker bar do not push all the way in the setting wheel, or they move back when turning the crown. You can take some pictures from straight above and these should show how the gears mesh. 

I’m sure that they are not meshing correctly as I can feel then grinding one in the other, I just can’t figure out why when all is put back together as it should and no visible damage is seen. I’m thinking (this crossed my mind while going to bed yesterday) that maybe the setting wheel post got bent in some way.

[Nucejoe]

3 hours ago, jdm said:

 You can take some pictures from straight above and these should show how the gears mesh. 

How about a video of the mech while changing from wind to set position, slow down the motion and if you didn't see a fault let us see the vid too.

[clockboy]

Some movements the intermediate wheel has a slight bevelled edge one side. So they can be fitted upside down.