Removing an overlayed date wheel

[jerkstore 14]

Sometimes (like when you re-set the keyless works), removing the ETA 2836 datewheel (DW) is a necessary evil.

 

The easiest way to do this is to depress the double jumper spring, and shift the DW slightly crown-side (to free it from the minute train bridge, which covers the keyless works) while lifting it off. The problem of course, is that most rep datewheels are overlayed. And the overlay hides the double jumper spring from view. Needlessly removing a datewheel overlay is a PITA, because getting it straightened out again is time consuming.

 

The other accepted method to free the DW is to unscrew the date jumper maintaining plate and/or minute train bridge by just enough. Too much unscrewing, and a little bad luck can sometimes push a part or two out of place--a real headache.

 

What to do?

 

Funny you should ask: I happen to have an A2836 sitting on my workbench...

 

 

 

One solution is to remove the DW blind. You can do this by inserting a very thin object under the DW in the direction of the double jumper spring. Then you just lift everything off like normal. Yes, I'm cheating because I'm looking. But this is the best way to demonstrate the technique.

 

Our target: between the 5 and the 6.

 

 

I used a blue oiler.

 

 

In this picture, the double jumper spring is pushing against the gap between the teeth of the DW (see dates 7 and the 8).

 

 

Pull the crown into the quick-set position. Turn it so the teeth just appear between the grooves in the date jumper maintaining plate:

 

In the picture above, look at the teeth near 7, 9, and 10. If you could somehow lift the DW vertically, those teeth would pass easily through the spaces in the plate. The problems with doing this are that (1) the spring is above the tooth near 8. Also, the teeth on the other side of the DW are beneath the minute train bridge. Forcing things here is inadvisable. You need to push that spring in.

 

 

 

Spring is depressed:

 

 

Lifting up while pushing slightly crown-side:

 

 

 

Done:

 

 

Now, this is tougher when the DWO is actually on. Probably the most difficult part is determining when the DW teeth are in the right grooves for lifting. If you pull up prematurely, the DW isn't going anywhere. Turn the crown until the date almost clicks over-- you can tell by the increasing resistance as you turn the crown.

 

You get the hang of it, eventually. Give it a shot!

 

 

***Update***

(1) Here's how you put the overlayed DW back on, without unscrewing anything:

http://www.rwg.bz/bo...showtopic=52048

 

(2) KBH rightly pointed out that this method can't be applied to the 2824. It's DW sits too low.

Edited May 20, 2013 by jerkstore

[LightGeek 25]

Excellent. Visual learners rejoice!

[SSTEEL 0]

Thanks for posting this, really appreciated.