WS 11: HOW TO remove and replace a watch movement
Case opener matching the type of the case back of your watch
Watch case holder (bottom left) - not absolutely necessary if you have a strong grip or if case back does not sit too tight
A movement pad or a similarly suited clean small piece (2 by 2 inch or 5 by 5 cm) of an old workpad or linoleum.
A movement holder to place the movement dial down after it has been removed
Small watch maker's screw driver (size depends on size of setting lever screw), normally size 0.8 mm or 1 mm. Please note, the size of the screw driver should always match the length of the screw. Never use a too small screw driver, if the screw sits tight, you will "butcher" the slot. Inexpensive so called "Precision Screw Drivers" made in China can do the job equally well. Just be aware that those screw drivers normally have pretty soft tips that bend easily if the screws sit firm. Going for the more expensive screw driver kits might pay off. If the Bergeon or A&F screw drivers are too expensive for your budget, try a Taiwan or Japan Made set that will be less expensive.
A digital camera to document intermediate stages of your watch work
Rodico (something similar to kneading wax) is always coming handy: to remove finger prints in this case. The uses of Rodico are almost unlimited. My watch tutor once said "how did they work on watches before Rodico was invented?". Visit www.nam-hing.com or www.ofrei.com to check it out. I am not related business-wise to either of those sites.
Sources for tools are (no business relationship with either of the shops): www.ofrei.com and www.nam-hing.com
Opening the case back
You had a look at the case opener table and are confident you have the right opener for your watch. If not, do not tinker unless you do not care whether you will leave marks on the case back! Go and buy the right tool and do a good job and be happy!
You have a strong grip or have a watch case holder and a small vice that you could if the case back sits very tight.
Opening quartz watch backs is normally quite a pain in the neck. Sometimes those pressure fit case backs - also called snap-on case backs - sit so tight, you will need a HOROTEC Case Crab to get the watch open without damaging the watch case or back. Everbody has its preferences, for me, the Bergeon case back lifter is often the preferred choice. If you open quartz watches with the Bergeon tool, always try to protect the area where the opener's feet stands on the bracelet or case. I use two layers of paper (if I expect it to be closed very tightly) or two layers of scotch-tape if I think it is going to open quite easily.
Screwed watch backs are normally quite easy to open, if the factory robot did not tighten them too firmly. My experience shows that e.g. SEIKO closes some of their Titanium Diver's for eternity. In any case, if the case back sits too tight, visit your watchmaker or a tool shop and get advice. It is not fun to scratch a watch back, trust me!
Steps to take the movement out
If your watch has a spacer (a black or white plastic or metal ring that holds the movement in place, normally found in less expensive watches) do not lift it out yet. Leaving it in has a good reason, the movement will not move inside the case if you start pulling on the stem to remove it.
with pushers: There are
two basic retaining systems for the stem: a spring loaded pusher or a
screwed setting lever. Japanese movements often have a little arrow or
inscription "push here" next to the pusher. I use an old oiler
with a filed down round tip as a pusher. A pin could also do the job. Use an
Arkansas stone to take off the sharp tip. Do not use peg wood or tooth picks
for this job as small bits might fall in the movement. You would be
surprised how rough the surface of a tooth pick looks under 40 times
How to do it: push down on the pusher while the other hand pulls on the crown stem. Normally it takes only about 0.5 to 1 mm way down and then the crown stem is released. What or who is holding the watch? A movement holder is a good idea for this kind of work. I have however seen watch makers holding the movement in their open left palm, pressing the pusher down with their left thumb while pulling the crown stem with the right thumb and index. This "flying" version can be risky, if you do not have a lot of practise, go for the movement holder or place the watch on the workpad in a way that it will not move if you push down on the pusher. Continue at Step 4
|An older Citizen "PermaBright" as a sample for a push release of the setting lever. Click for bigger picture!||Another Miyota movement with an inscription "PUSH" on the movement and a recessed release for the setting lever. Click for bigger picture!||The SEIKO 6309B has an easy to identify pusher right next to where the stem enters the movement. I have marked it with the red pin. Click for bigger picture!||The ubiquitous SEIKO 7S26 has a little lever with a little indentation that allows you to use about any small pointed tool to press down perpendicularly and pull the crown out. Click for bigger picture!|
Note: If you cannot find a pusher, check for a screw (next step). If there is neither a pusher or a screw, then try this: pull the fully out and watch the area where the stem enters the movement. On some watches, a little lever will swing out when the crown is fully pulled out and that little lever has normally a small indentation which you can press down in order to release the crown stem. I have seen this occasionally on Quartz movements.
Movements with screwed setting levers:
movements normally have screwed setting levers. The setting lever is a
little spring loaded lever that retains the stem if the crown is pulled out,
e.g. in order to set the time and date. There is a picture of an AS 1130
movement with the marked location of the setting lever screw at the bottom
of this page.
How to do it: Open the setting lever screw 1 to 1.5 turns only! Why is this red? Because if you open that screw and the screw disconnects from the setting lever, you will have take off the dial and hands in order to assemble it again! This is one of the most common traps for amateur watchmakers and of course I stepped into it once or twice too even I knew exactly 1 to 1.5 turns only. It normally happens if you open that screw 1.5 turns and the stem does not move out even you pull firmly. Instead of opening the setting lever screw 2 or more turns and ending up having to take off the hands and dial, WIGGLE the stem a bit while pulling it. The stem's collar has to slip under the retaining setting lever. Even better: open the setting lever screw one turn and then try to pull. Add another half turn and pull again. If the stem still does not come out, push the stem/crown completely in and out again, sometimes this will free it too. In any case, do not open the setting lever screw too much, if you did, you willl have to follow this link: how to remove hands and dial in order to rearrange the setting mechanism in its original position.
|An AS1130 Handwind with a screwed setting lever||An ETA Quartz movement with a screwed setting lever|
|Note: If you cannot find a screw, check for a pusher (previous step). If there is neither a pusher or a screw, then try this: pull the fully out and watch the area where the stem enters the movement. On some watches, a little lever will swing out when the crown is fully pulled out and that little lever has normally a small indentation which you can press down in order to release the crown stem. I have seen this occasionally on Quartz movements.|
Now carefully lift the spacer out or open the case clamp screws. There are normally 2 to 3 case clamps that are screwed on the movement . Rolex calibers e.g. require that the movement is first rotated to a certain angle, before they can be removed. You can easily see from the shape of the inner case, what position that ought to be.
|Sample of case clamps of an ETA Caliber 2836-2 inside a Titoni Cosmo King Day-Date. Note, the watch has also a white spacer ring. In addition you will see the pusher location for releasing the stem (small circle next to upper case clamp). The lower case clamp is covered by the rotor. You will have to move the rotor away to unscrew it.||In this picture you see the stem removed already, also the two case clamps and case clamp screws are removed. The weatch is ready to be turned over so the movment should remain on the movement pad if you lift off the watch case. The yellow line points to the collar of the stem, that is the part what will prevent the stem from falling out when you pull the crown out to set the time.||Rolex e.g. uses case screws with collars on this Caliber 1570 (DateJust from 1978). The trick here is to lift (open) the screws to push the movement into the case and hold it. I was surprised myself to find that the screws did not open because I turned them the wrong way at first. You have to turn right to turn those case screws down and then the movement is freed.|
Place a movement pad or another clean and suitable piece of plastic or other material over the movement and turn the watch over. If you lift the watch case carefully up now. Please note: watches with date pushers, alarm watches with two winding stems, chronographs or other complications are not covered in this instruction. With a common sense for mechanics, it is however pretty easy to study how the pushers connect to the springs on the movement. E.g. for most Casio watches, the movement can be lifted out without too much troubles.
Now the movement lays dial-up on the movement pad. Finger cots or very clean hands are required now. Carefully lift the movement up and place it dial down on a plastic movement holder or an other similar suited tubular item for a first inspection. Be extra careful with black dials. Finger prints can be removed with Rodico, the miraculous material that can be used in so many ways.
Taking the movement out and looking at it from the side sometimes reveals tangled or damaged hairsprings (balance spring). You might also want to re-insert the stem now (see below).
The first part of the instructions ends here, the movement is removed for a visual inspection or you might want to take it out just to look at it. To continue working on your movement, you will most likely want to remove the hands and the dial
Note: In most cases you will insert the stem again for additional work on the movement. One is always happy to have that handle, it is the safest way to turn over the movement and reduces the risk of fingerprints too.
Steps to replace the movement:
Place the movement dial up on the movement pad
Carefully place the watch case over the movement
Turn the watch over and place it into a watch case holder
Replace the case clamps and insert the case clamp screws but do not tighten them yet or replace the spacer.
Insert the stem: sometimes
you will have to try a couple of times to insert the stem properly. Do not
apply too much pressure, a cracked stem could be the consequence. Most
quartz watches or most mechanical watches with a pusher to release the
setting lever will allow you to simply push the stem back in. Check its
proper position by pulling it back out. If the stem comes out again, it was
not properly replaced. For watches with setting lever screws, be again very
careful not to open the setting lever screw too much. Due to the shape of
the collar on the stem, it should actually be possible to push the stem back
in without touching the setting lever screw (still 1.5 turns open) again.
If the stem does not want to go back in, simply pull it out again and try again. Do not wiggle it around while trying to reinsert it. A dislocated castle wheel might be the consequence. In the picture below you see a dislocated castle wheel from a Sandoz ETA Caliber 2836-2. What are the symptoms of a dislocated castle wheel? You can wind the watch, but you can not set the time.
|ETA 2836-2: This dislocated castle wheel (should be further to the right following the yellow arrow) was the cause that the watch could be handwound, but would not allow to set the time. The castle wheel can be dislocated if you do not insert the stem perpendicularly or wiggle it around while trying to get it in place.|
Please note that tighten the case clamp screws is a lot easier and safer if the watch is in a watch case holder
Before you close the movement, turn over the watch and check whether the dial is aligned properly. If all is perfect, tighten the case clamp screws.
If you were working too enthusiastically and forgot to take a movement picture, take it now
Close the case back
You are done, now you know a lot more about your watch and hopefully all went well.
If you have questions regarding this instructions, please ask on www.pmwf.com, I get more and more emails per day and am simply not able to answer all watch related questions in individual mails. In addition, we have now about 900 registered PMWFers (March 2004) and you have the chance to get much more competent advice on the forum then if you simply mail me.