Stem Length: Too Short vs Too Long (Brain Teaser)

[Ronin]

After a recent haul / buying spree, I have no fewer than 3 watch all exhibiting what I believe to be stem length issues.  Although I have built many watches, I never had any of these issues with my builds.

 

So from a diagnostic perspective any help in matching up these symptoms with too long vs too short or something else, please chime in and help me out, as I set out to fix them.

 

#1 (Noob): Unscrewing the crown, the watch fails to go into manual winding position about 50% of the time.  It just free spins doing nothing when it should be winding. I can usually jiggle it, or pull the crown out to setting and push back in to winding position.  (too short, too long, something else like clutch on Rolex crown)

 

#2 (GMF): Sometimes when pulling the crown out, it will go straight to 'date setting' position. You think you are manual winding, but instead you start flipping the date. (too short, too long, something else)

#2a (GMF): Attempting to screw back down the crown is very difficult, especially with a full wind when fighting the mainspring.  It is very difficult to get the Rolex crown to engage the tube threads and then 'clutch' and free spin when screwing down.

 

#3 (Noob): When manually winding, it will occasionally make a loud CLICK like it is slipping or failing to stay engaged with the winding pinion. (too short, too long, something else)

 

Thoughts?  Anyone want to take a crack at this?

[Timelord]

Very valid points!!

 

i myself had these issues in the past!

 

I noticed that if the movement is not held firmly by case ring screwed in properly)I seem to have issues where the stem does not always seem to pull out into the right position!  You have lateral play and this causes stretch on your keyless works! When you cut the stem, do you measure it with case ring  tightly fixed or with the dial just in position of dial seat where stem is just slightly longer pushing against the case?

 

I have had this problem also if the stems are generics or faulty!  Sometimes it is also the keys works that have some slack! At the moment I have 3 mvts with keyless works problems and unless you replace the whole keyless works they don’t always mesh up by buying individual parts 
 

I have also experienced some of the issues you mention when the movement is not right for the case!  Ie fitting an eta 2824-2 into  a case made for the eta 2836-2. I assume you are referring to the  eta 2836-2 you are having these issues!  
 

I find the correct case clamps  also play an astronomical difference, as ones that come with the case from factory seem  to be dead right !  Making your own or trying to file down the right size is either a hit or a miss!  I struggle with case clamps in getting them right!

 

Hope this gives some feel for what I have noticed! good luck!