Junghans vintage J87- can't get the crown/stem out.

[KevinMc]

I've loosened the screw but it just won't come out. watch looks very worn but no obvious sign of corrosion inside. I jiggle it and twist it but it's just jammed in there. I'm new at this and don't know how much force i can use to remove it (but i'm guessing none). should I try taking the movement apart without removing it from the case?

[WatchMaker]

You're right not to force things and right that it shouldn't take much force to remove the stem.

It's usually one-and-a-something (e.g. 1.5) complete turns of the setting lever screw for the stem to release. Just to check this, screw back up tight then turn one revolution and whilst applying gentle pulling pressure on the crown continue to undo another half revolution or so. Any joy?

I've worked on a movement before that visually looked fine and corrosion free but where some small moisture ingress via the case tube had fused stem and clutch wheel together so stem would not release. However this also caused crown in/out (winding position to time change position) to also not be possible. Can you do both?

Next question is why you want to remove the stem. If it's to service the watch you've got nothing to lose in removing the barrel bridge etc. to see if you can figure what's going on.

[anilv]

On some movements, you need to screw in to remove the stem. counter intuitive but I've come across it, can't remember what movement though.

Anilv

[KevinMc]

17 hours ago, WatchMaker said:

You're right not to force things and right that it shouldn't take much force to remove the stem.

It's usually one-and-a-something (e.g. 1.5) complete turns of the setting lever screw for the stem to release. Just to check this, screw back up tight then turn one revolution and whilst applying gentle pulling pressure on the crown continue to undo another half revolution or so. Any joy?

I've worked on a movement before that visually looked fine and corrosion free but where some small moisture ingress via the case tube had fused stem and clutch wheel together so stem would not release. However this also caused crown in/out (winding position to time change position) to also not be possible. Can you do both?

Next question is why you want to remove the stem. If it's to service the watch you've got nothing to lose in removing the barrel bridge etc. to see if you can figure what's going on.

Thanks for responding! 

At first I wasn't able to set the time (wasn't running, either). once i got the caseback off and unscrewed the setting lever screw some it 'jumped' tiny bit and started ticking. i was able to pull the crown out then to the setting position and move the hands. However, maybe i unscrewed the setting lever screw too much because now it won't click into the setting position. 

Ultimately I want to try taking it apart and cleaning it. this is my first learning watch. The watchcase is heavily worn; plating wore off and the brass beneath is eroded from contact with skin, crown is very worn down. but aside from the case the watch looks nice inside and the dial looks great. it's was loved for a long time.

I'll give your suggestion a try but i fear i already went too far and i'll have to take it apart in the case.

 

Edited February 4, 2022 by KevinMc

[KevinMc]

alright an update. finally got the stem out and yes, it was corrosion. seems to be a very snug fitting stem so a little corrosion was enough to swell the stem. winding and setting knocked it off where it rubbed on the case tube but there was probably a shoulder of rust that prevented it from coming out even after it was disengaged. 

it took quite a bit of force to remove it using pliers. the crown broke off but needed replacing anyway. probably need to replace the stem as well since i think i marred up the threads. 

The next problem is that the movement is in there really tight in the case and won't budge.

[LittleWatchShop]

I have run into this situation once before due to rust.  What I did was to disassemble the with in situ.  Get all of the dainty parts out...or all of them.  Then you can work the issue of removing the main plate.

[WatchMaker]

23 hours ago, KevinMc said:

The next problem is that the movement is in there really tight in the case and won't budge.

Assuming that picture of your movement is the current state, it looks like you still have the case clamp screws in place (the two large dome head screws on the perimeter of the movement). You'll need to remove these.

[KevinMc]

7 hours ago, WatchMaker said:

Assuming that picture of your movement is the current state, it looks like you still have the case clamp screws in place (the two large dome head screws on the perimeter of the movement). You'll need to remove these.

No those are out but thanks for the suggestion. maybe it's the rust dust. 

If I get a crystal remover maybe i can push it through the face?

Edited February 8, 2022 by KevinMc

[jdm]

On 2/7/2022 at 5:07 PM, KevinMc said:

it took quite a bit of force to remove it using pliers. the crown broke off but needed replacing anyway. probably need to replace the stem as well since i think i marred up the threads.

That's a pity. Everyone breaks something but the idea is to repair without breaking. You could have placed and left few drops of rust remover (even tea works) before exercising any force.

 

On 2/7/2022 at 5:57 PM, LittleWatchShop said:

I have run into this situation once before due to rust.  What I did was to disassemble the with in situ. 

Normally that is not recommended, but when the keyless is fully accessible top size that is a good way, combined with dissolving rust in situ above.

 

11 hours ago, KevinMc said:

If I get a crystal remover maybe i can push it through the face?

Of course it has to come out from the top, it's a front loader case, that is the most frequently asked question by beginners. Be aware that good crystal lifters are expensive, on old watches sometime on can get it out by pushing up gently with a 2mm screwdriver across 2 or 3 points at the base of the crystal.

[KevinMc]

8 hours ago, jdm said:

That's a pity. Everyone breaks something but the idea is to repair without breaking. You could have placed and left few drops of rust remover (even tea works) before exercising any force.

 

Normally that is not recommended, but when the keyless is fully accessible top size that is a good way, combined with dissolving rust in situ above.

 

Of course it has to come out from the top, it's a front loader case, that is the most frequently asked question by beginners. Be aware that good crystal lifters are expensive, on old watches sometime on can get it out by pushing up gently with a 2mm screwdriver across 2 or 3 points at the base of the crystal.

yep beginner here. I couldn't confirm it was rust or my lack of understanding of how the stem should release. Tea, eh? I'm trying it on the stem now. Maybe I can salvage it.

front loader? (meaning it has to come out through the crystal?) how can you tell?

[jdm]

53 minutes ago, KevinMc said:

how can you tell?

The dial is larger than the mov.t. Enter "front loader' in the search box top right. And search also for anything else you are not sure about or equipped for, before assuming or taking action.

[clockboy]

This post is I am  afraid a common issue on this forum. Many including myself watch vids and it looks so, so easy BUT most of the vids have been edited with the flyers up- cocks etc  edited out. Successful watch repair requires skill, experience and knowledge which can not be gained by watching the pros vids. Anyone considering watch repair start on a easy low cost movements such as a pocket watch and treat it as part of the learning curve. Handling a screwdriver and small parts requires skill and patience, assembling is yet another skill that can destroy a watch if not carful. In this case a stuck stem would not be a huge issue for a watch repairer with experience. 

However it can also be extremely satisfying when the final result is a dead movement has been transformed into a up and running movement.