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Installing Valjoux datewheels on an Asian 7750


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This is a step-by-step tutorial on how to change the datewheels on an Asian 7750 copy. I'm performing this upgrade on an ETA 3717 replica provided by Stephane for this very task.

There are a lot of pictures so please let them all load before starting. Also, when replying DO NOT quote the whole post as you'll make a lot of enemies that way. We don't need to see all the images twice.

Firstly, you'll need tools. These are all the tools I used:


From left to right, top to bottom.

* Toothpicks (invaluable tool from which you can fashion ad hoc tools), silicone grease (not essential), a movement holder, Glass Bowl.

* Tweezers, push-pin-poke-thing, awl, screwdriver (that's a Bergeon 1.2mm, but 1mm would do as well), hand removers, rodico putty, Joe the Blow

toothpicks again, Romy and Michelle's finest invention - post-its.

* Case opener, greaseproof paper, Cloth

* Watch box pad, Leatherman Wave.

Oh, and here's a better view of the bowl.


I'm going to let the pictures do the talking and, if as promised, they're worth a thousand words each, this is a whopping 76,000+ words long.

Here's the watch and wheels:


Open the bracelet using a toothpick and a pusher.


Store the parts


Open the caseback


Note the use of a spring and inside cover to hold the movement in. This wavy circular spring and the stem are the only things holding the movement in place


Take off the rotor


Remove the stem. If you can't do this, you have no business on the dial side.


Tip the movement out onto a piece of paper


Store the case and caseback under a dust cover. You really, really need to do this on the 3717 as the AR coating inside the crystal should never be touched.


Put the movement in the holder.


Open the dial clamps.


One of these clamps was actually broken, showing replica QC at its best.


Remove the hands.


Using post-its to protect the dial.


small hands too


Then lift the dial off. There was tape as well as clamps, which is why they can get away with a broken clamp.


Movement without dial:


The day wheel just lifts off


Note this spring. I've lost one of these learning how to do this, so please be careful.


These are the screws we'll be removing



Here's a technique I learned to not lose the spring. Put a clump of rodico putty over the visible bend like so.


remove the previously mentioned screws and the plate they hold in. This is the only fixed part of the movement we'll be removing.


This lever makes the date roll over neatly. It's not held in with anything, so be careful.


Gently lift off the date wheel on the left and slide out to the right. Be careful not to ping out the lever.


Here's the base without the wheels. Use this as a reference if any pieces pop off.


Put in the ETA part on the right, under the change mechanism and work it in on the left, carefully. I'm using a post-it and thumb to hold in the lever so it doesn't fly awaywhile I'm replacing the spring that worked loose.


This is everything put back


Put the covering plate back on


In place, all tidy.


Put the screws in



and remove the putty.


All tidy.


The day wheel drops in neatly


Get ol' Joe out for a blow, but be gentle as you can easily lift the day wheel with Joe's gusts.


Put the stem back, drop on the dial (with clamps).


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Stick a hand to a post-it to place it on the post.


Make a hand pressing tool using a toothpick.




Press the hand on


You can use Rodico instead of a post-it if you prefer.


Both little chrono hands on


And the sweeping seconds


One toothpick method for fitting hour hand.


Or use a custom tool


Note bent minute hand. This is an IWC speciality to reduce paralax errors reading the time.


On it goes


Set the hands until the hour jumps and that's midnight. This watch jumps about here:


The second hand has a bent tip too


All on!


See the angles?


Disaster! The chrono second hand isn't millimetre perfect! Let's remove it and refit it.


And now it's perfect.


Put the spacer ring back on. Note the pushers. These can fall out. Please don't lose them!


Drop the case over the movement, after a judicious use of Joe, obviously!


Fit the rotor back on


Then the first cover


Remove the o-ring


Get the grease out


Grease the o-ring


Refit the ring



Case spring


Put the caseback on




Check it out... looks good!


refit the bracelet


with a prodinator


Check the chrono


resets perfectly


... and wear it well!


You're done

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Very nice work Pug! :)

I tried to change the datewheel on my Carrera Chrono by myself, but that little spring fell off.. Did not have an step-by-step procedure like this.. So now it is by The Zigmeister, changing to an ETA.

I remember an post over at RWI about this, showing an official ETA-sheet, which was very informative

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AAAAAhhhhhrrrrrggggghhhhh :Jumpy:

My goodness Pug, what a stress reading this tutorial based on my watch !

I'm so happy you did it !

I do not think I would have ever tried myself :2:

Thank you so much!



Here is the watch before Pug's work...

Not obvious, but the day/date did not align correctly though.


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Great post Pug... as always :thumbsupsmileyanim:

There's 1 thing I don't understand though. Did you remove the hands and reinstall them after you noticed the hands were not aligned at midnight (date change)? Or did you give them a slight tap to lign them up (hope this makes sense)?

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There's 1 thing I don't understand though. Did you remove the hands and reinstall them after you noticed the hands were not aligned at midnight (date change)? Or did you give them a slight tap to lign them up (hope this makes sense)?

The date changed close enough to midnight for it not to be a problem. I did remove and replace the chrono second hand, though, as it wasn't perfect first time.

Just one thing - what you refered to as a case spring - I thought it was the antimagnetic shield.

There are two parts: a spring and the shield. You can see the spring in the top middle of this pic:


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I really needed this. Thanks for taking the time to instruct us. This should be a sticky.

A question - is it necessary to remove the rotor?

and - did you ever find that spring or did you have to get another one? :thumbsupsmileyanim:


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A question - is it necessary to remove the rotor?

and - did you ever find that spring or did you have to get another one? :thumbsupsmileyanim:

You remove the rotor to make things easier. It's a 2 second job, so why not? :D

As for the spring, I scavenged one from a dead 187 I got for the case, along with a screw for the plate over the spring as my 3717 was delivered with only one screw installed.

Oh, that reminds me. Stephane's movement appeared to have a spare screw floating around inside. Yes, a screw that simply shouldn't have been there fell out of the movement! :blink: It was the same as the rotor screw, so one probably dropped in the movement during construction. Stephane, I just saved your watch from seizing for no apparent reason sometime down the line.

This goes to show that no matter how much better the QC is getting, you're still relying on a Chinese worker more concerned with units than quality. I understand what The Zigmeister is on about more and more.

If you like fairy tales about how good replicas are, don't learn how to take movements apart. I'm dreading what I'll find when I start taking movements apart properly. :unsure:

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Thanks for saving my watch.

I'm glad you have a spare screw now that it's not floating in this 7750!

I guess that when you will have modified a 100 watches you will be in the position of opening a screw shop :lol:

So, you are definitely right : quality control is a fairy tale :black_eye:

It's a pity



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A word about my rotor question. The reason I asked is that I killed a bad replica once by removing the rotor. The race seperated and all these little teeny weenie microscopic ball bearings fell out. Just one more thing to worry about.

Thanks again for the tutorial. I will be using this but right now the 3717 is so expensive I can not afford it.


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No obvious c0ck-ups?

None...my only suggestion, would be to ditch the toothpicks, and get a red/grey bergeron hand installer, they run about $15 or so...much better and allows great control over hand installation.

It's not a c0ck up, just a suggestion.

The only other comment is I shy away from using tweezers on the date/day wheels, too easy to scratch them, datewheels are as fragile as a dial, much better to use rodico to pick them up with.


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