Seiko 7S26 Crown Removal (from stem)

[RickTock]

Greetings! I would be most grateful if someone would share how to remove the crown from a stem. The crown/stem in question is from a 7S26 equipped Seiko 5. I can grab the stem with a pin vise and give the crown a twist, but the crown is very tight and I'm afraid I'll just break the stem. Should I heat the crown? If yes, recommended method? Remove the gasket first? Many thanks!

 

[HectorLooi]

The crown is sometimes fitted on with threadlocker. So, heating the crown is the way to go. If it still won't budge, then try soaking it in acetone overnight.

[watchweasol]

Hi regarding heating the crown. Use a soldering iron to transfer the heat trying after each application to remove the crown.

[LittleWatchShop]

11 hours ago, RickTock said:

Remove the gasket first?

Yes

[Marc]

Just curious, but why do you need to remove the crown?

The pic suggests that the crown is in good condition, although we can't see the end of it. The stem looks good too. The gasket can be easily replaced without removing the crown.

 

[RickTock]

13 minutes ago, Marc said:

Just curious, but why do you need to remove the crown?

I'm swapping in an NH36 movement which uses a different stem. I'm hoping the crown will thread onto the NH36 stem and figure the best way to find out is try.

[Marc]

17 minutes ago, RickTock said:

I'm swapping in an NH36 movement which uses a different stem. I'm hoping the crown will thread onto the NH36 stem and figure the best way to find out is try.

That makes sense

[RickTock]

18 minutes ago, RickTock said:

I'm swapping in an NH36 movement ...

In the photo in my first post you can see from the misaligned day display that I have not swapped the day wheel over to the new movement yet. Still in test-fitting, head scratching, pondering meaning of life mode.

[RickTock]

Thanks to all for the advice and comments. Very much appreciated.

Heating the crown certainly did the trick to get it off of the old stem. I learned a little though, as my first and second attempts (when I was touching the soldering tip right up to the big end of the crown) were unsuccessful. I decided to touch the soldering tip to the back of the crown, and that did the trick. I didn't realize that the crown actually extended back as far as it did, but of course that's where the stem threads in and bonding agent needs softening.

The watch is all back together with its upgraded movement and ticking happily away on my wrist. The old 7S26 will eventually be stripped down, cleaned, lubricated, etc.

Photo is of the removed crown, the 7S26 stem and for comparison, the new (uncut) NH36 stem.

[kd8tzc]

@RickTockwhat happened to the little rubber gasket that was on the crown in the first picture?  I am doing the same thing (switching the 7S26c for the newer movement) but I'm concerned that the heat will destroy that gasket.

[RickTock]

37 minutes ago, kd8tzc said:

@RickTockwhat happened to the little rubber gasket that was on the crown in the first picture?  I am doing the same thing (switching the 7S26c for the newer movement) but I'm concerned that the heat will destroy that gasket.

I took the gasket off before I applied heat. I used my #5 Dumont tweezers (really sharp) to get in and around both sides of the gasket and work it off. Even still, I did manage to nick the gasket, so it had to be replaced.

[kd8tzc]

Okay... I was wondering if the gasket was moveable or glued down... mine doesn't want to move when I use a piece of pegwood. 

Do you have the item number and where to order a replacement if I need to do that?

[RickTock]

27 minutes ago, kd8tzc said:

Okay... I was wondering if the gasket was moveable or glued down... mine doesn't want to move when I use a piece of pegwood. 

Do you have the item number and where to order a replacement if I need to do that?

The gasket is not glued down, but hard to get out of the deep groove in the crown without inflicting damage (at least with my novice skills).

For a new gasket, first I went to http://cgi.julesborel.com/ and searched for my case number. For my watch, I searched for  SEK CS#7S26-01H0.

Then click on the link for Gasket, Crown/Stem. Part number for my gasket was DB0055B01 (yours may be different).

You can order gaskets individually from Cousins (or other vendors). I chose to order an assortment that included the gasket I needed.

Best of luck!

[HectorLooi]

If the old gasket has hardened, the only way to get it out is to cut it. Attempting to dig it out with a metal instrument would result in damage to the crown tube.

[thor447]

11 hours ago, RickTock said:

The gasket is not glued down, but hard to get out of the deep groove in the crown without inflicting damage (at least with my novice skills).

For a new gasket, first I went to http://cgi.julesborel.com/ and searched for my case number. For my watch, I searched for  SEK CS#7S26-01H0.

Then click on the link for Gasket, Crown/Stem. Part number for my gasket was DB0055B01 (yours may be different).

You can order gaskets individually from Cousins (or other vendors). I chose to order an assortment that included the gasket I needed.

Best of luck!

This is a great set, especially if you work on a lot of Japanese movements.  #10 in the set is the DJ0060B01, and you'll use 2 of those for every 1 of everything else.  I ordered about 20 more of just that size just for stock, which isn't bad at all at only around 0.20 per, compared to $5 to $7 per from eBay or other supply houses for a factory gasket.