7750 or 7751 stem issues

[Folkvisor]

I was wondering if the stems on 7750 or 7751 watches are known to be a bit tricky to replace. 

It was difficult to remove and now it isn't cooperating when I want to refit it.

Any ideas and advice is welcome.

[bjd1020]

Ive never had much an issue

Sent from my SM-G950U using Tapatalk

[nickelsilver]

They're pretty normal as far as stems go. Unlike some modern calibers you do need to depress the detent when installing. If it's resisting give it a twist while inserting. If the movement is in the case it could be the gasket in the crown is hard and tight on the tube and that's causing some resistance.

[watchweasol]

Hi I have enclosed the 7750 tech sheet  the exploded diagrams maybe of some help in locating the problem , usually they just push in with a little wiggle,perhaps crown wheel and castle wheel are out of line> I sometimes use a small screw driver in the apperture to line them up and try again. 

eta_7750_tech_sheet.pdf

[Folkvisor]

Thank you for sharing your experience. I will try realigning everything with a small screwdriver and then try reinserting the stem again. 

It’s kind of frustrating getting through everything else in a rather complicated movement and then having a problem reinserting the stem.

[HSL]

For some reason I forgot how the stem in the 7750 went in so lucky me I had a couple of brand new movements lying around so I didn't have to take a watch down just to still my curiosity. 
Almost immediately when I took the stem out it al came back, as you see on the picture the stem will with ease goe in a bit but not the whole way without some force, if you push the stem release button slightly it just propps in like a coin into a peepshow booth.
Think it might have to do how the stem is designed and in how good shape the setting lever is in. Adding a picture of the stem too...

[Folkvisor]

Thank you for the detailed photos!

I had already screwed the crown onto the stem so I could measure how much to cut off and I solved the problem by watching what was happening through my loupe. (Who knew this could help?) Anyway, it seems the round groove in the crown wasn't lined up with the tube and so it would only go as far as the crown would allow it to go until I got the two aligned 'et voilà!' - it's in.

Now I have to take it out again and cut off the stem twice so it's still too short!

I had to order 2 stems for a 2836-2 once.

I'll try to be more careful with this one. 

[Folkvisor]

2 hours ago, watchweasol said:

Hi I have enclosed the 7750 tech sheet  the exploded diagrams maybe of some help in locating the problem , usually they just push in with a little wiggle,perhaps crown wheel and castle wheel are out of line> I sometimes use a small screw driver in the apperture to line them up and try again. 

eta_7750_tech_sheet.pdf 7.27 MB · 0 downloads

I think it also helped to insert a screwdriver to align everything.

[Folkvisor]

Just a heads up for anyone working on a 7751 Moonphase: 

The Moonphase Star can be a bit tricky. Not much holds it in place and it can move while putting on the dial. Make sure the dial is held firmly in place while setting the ETA clamps on the dial feet. If not, the Moonphase Star can come loose.