Guide to replacing the Asian 7750 with an ETA 7750

[ajoesmith]

I was doing this transplant last night and thought it shouldn't take too much extra time to snap a few pics along the way to post here and give other members a look and see whats involved.

I want to make it clear that im NOT a watchmaker or any kind of watch guru, im just a hobbyist and do this stuff in my free time. I started my interest in reps when i was about 15 years old when my friend had a rep Tag Heuer. I was very envious and really wanted one but at that time they were only available in asia etc... and i wasnt going on holiday anytime soon. Anyway i got my first rep, a submariner, and though it was the dogs bollox. Now i have to laugh, a 17 year old with a rolex - yeah right!!!!

Well 10 years later and ive gone off rolexes and like Omega, Panerai and Breitling to name a few. Im quite technically minded and always like mechanical movements and wondered how they work. Ive recently just stripped an old asian 7750 and put it back together and it works!!!!, great sense of satisfaction.

Ive had no proper training and just do this hobby by trial and error, and with a little help from RWG as guidance. The methods that i use are by no means the best and certainly not endorsed by watchmakers but they do seem to work for me and achieve the results that i want.

Im doing this tutorial/pictorial just to let people see how its done. Feel free to try these methods but if your are not technically minded DONT dive in and expect to do a good job!, leave it to the pros like Mr.The Zigmeister

OK so i have a Chrono avenger and wanted to replace the old asian 21,000bph movement with a Gen Swiss ETA 7750. I read on this great forum that it was a straight swap. Great!!

I purchased the ETA 7750 from a seller on ebay check here: http://cgi.ebay.com/Watch-Movement-ETA-775...VQQcmdZViewItem

He's a great guy to deal with and can get a better price if you take more than 1, like i did!!

So just again what im doing, Im replacing an old version 21,000bph Asian 7750 with a Gen Swiss ETA 7750

On to the pics.

Here is the New ETA 7750 movement and the Chrono Avenger

Same again

My too small table with all the tools that ill need for the job!, of course you need a beer too (in the background!!)

Case back removal tool, think its called Jaxa?

Case back off!

Case back off!

Case back off!

movement holder screw no. 1, tweezers pointing to screws

movement holder screw no. 2

movement holder screw no. 3

Screws off

The tweezers are pointing to the crown stem removal button, im not sure of the correct term for this. Press this BUT NOT TOO HARD OR ELSE YOU'LL SCREW UP THE KEYLESS WORKS AND THEN YOUR IN A WORLD OF HURT!!

Before removing the stem in the above picture, adjust the hands so its 12 oclock, this will make it easier to remove the hands. NOTE ADJUST THE TIME TO 12pm NOT 12am AS AGAIN IT COULD MESS WITH THE DATE CHANGE MECHANISM AND/OR THE KEYLESS WORKS!

OK stem removed

Turn the whole watch upside down and out comes the movement and dial

Lift the case away

as above

BE CAREFUL HERE!!! For the chrono to work the movement holder has 2 small metal 'pushers' (again correct terminology? ive no idea!) these are not held in place and can easily fall out, be careful, not to lose them

Movement holder and movement

Hand removal tool

I use a piece of paper to protect the dial, probably should use lint paper but i dont have any!

Cut a v shape in it

Cut a v shape in it

The chrono Avenger dial has the rehaut attached to the dial and so it was very difficult to use the paper to protect the dial as i couldnt get the paper it place. I could have removed the rehaut but i didnt want to. In this case i didnt use the paper to protect the dial. I was just very careful to remove the hands. I didnt touch the dial at all with the removal tool. Not for the faint hearted!

Hour and minute hands off

The side of the movement there should be a device to hold the dial in place. 1 on each side of the movement. again i dont know the correct term for these but this particular movement didnt have them

To remove the dial i use a screwdriver and gently insert it between the dial and the movement. Be careful not to scratch the datewheel!!!. EDIT: Please note, i only insert the edge of the screwdriver and then twist it to lift up the dial

This method above also removes the small chrono hands as well!

All chrono hands off

Dial off

New ETA 7750 movement to be installed

Im also replacing the dial, the new dial is still a rep dial but better than the old rep dial

In this pic you can see the dial holder 'things', not sure what they are called.

Dial in place, can you spot the problem??

Again another pic can you see?

Plastic tweezers for the next job

and the hand press

30 min chrono hand on

12 hour chrono hand on

Second hand on

Second hand ticking ok

Second hand ticking ok

Hour and minute hand ready to go on

Hour hand on using the hand press, NOTE before putting the hour hand make sure the time is set to 12 o'clock.

I use a piece of tissue paper to press the hand back on so as i dont mark the hands

Hour hand on and testing to see if its on the right place

Minute hand on, all seems ok

Chrono second hand on

Checking to see if all is aligned ok, all is OK

Blow off any dust

:rolleyes:

[ajoesmith]

Ready to put back into the case, also blow off any dust on the inside of the crystal

Movement back in the case

Movement holder and chrono pieces

chrono pieces back in the movement holder

Holder in place

Movement screws screwed in. At this time i also check to see if the chrono is working correctly or not. actually the 30 minute chrono hand wasnt installed correctly and when i started, stopped and reset the movement the 30 minute chrono hand flew off. I had to put it on again

Crown and stem back in place

Case back on

Wrist shot, GREAT!

[shultzie]

wow...

That is one informative post. Quite the effort. Thanks for taking us all along on that trip.

[maxmilian]

Very nice writeup thanks.

[scoobs1971]

Thnx for this very informative post!

A few months ago I swapped the rep 2824 for a new ETA 2824. Wished I had this guide at that time. Funny to see that the principle is the same.

I made all the mistakes which you warn here for: forgot to blow off the dust from the dial, then forgot to blow off the dust from the crystal, then noticed that there were fingerprints on the dial since I didn't use the tissue, then didn't know how to place the hands back since I didn't know to set the watch at 12 before taking off the hands etc.. You don't want to know how often I had to re-open the case. And did I already mention that I screwed up the keyless work by pushing too hard, hahaha??

Would be nice to pin this item in the technical section.

[chubbchubb]

This is a great post, thanks Joe... I've done the same thing a few times already and unless you have a step-by-step guide like this one, you're sure to pay the price. It's little things like paper to protect the dial when removing the hands, tissue to protect the hands when installing them...

That's why (in addition to collecting gens) I love collecting reps... I would never dare to do that with one of my gens..

[triplehd]

Awesome job, but quick question. Did you have to replace the hands? I thought if you swapped the Asian 7750 for an ETA 7750, the hands (especially on the Chronos, would not fit on the ETA movement).

Again, awesome job !

[HauteHippie]

A fun and successful project! Nice pictorial.

[scoobs1971]

Did you have to replace the hands? I thought if you swapped the Asian 7750 for an ETA 7750, the hands (especially on the Chronos, would not fit on the ETA movement).

The hands of an old Asian 7750 will fit on an ETA 7750. However, the hands of the new 28.8 Asian 7750 won

[pitimany]

Excellent guide. Thanks

[ajoesmith]

Thanks, glad you liked it

[Admin]

Great post

Admin note: Pinnable

[torresp]

Excellent, I was waiting this post since my start in RWG and TRC. Awesome job.

Thanks

[Chronus]

Great write up

[Watchmeister]

Great post. Hopefully that will inspire folks to do the same thing.

[ajoesmith]

Maybe im just plugging my own thread but i think this should be pinned!

Admin/members what do you think?

[Pugwash]

Maybe im just plugging my own thread but i think this should be pinned!

Admin/members what do you think?

I think it's useful, apart from the bit that uses the dial to remove the subdial hands.

Sure, you can do that if you're replacing the dial, but otherwise isn't there a risk of marking the dial and/or pinging the hands across the room?

[chrgod]

A good tutorial, which could well be pinned.

Shame that it is only the old Chinese 7750 movement which is a straight swap with ETA.

If I remember correctly, Ajoesmith also made an excellent tutorial for freezing the 6 o'clock subdial on Venus 175 copy movements. I has been very useful for me. Nice work!

[dodger]

Which Bergeon hand remover do you have? It looks liket the #1...

Which one should I get the #1 or #6?

[fredman]

Brilliant............... thank you for all the info

[Skidbaecken]

Hi there,

excellent article, congrats!!

One question though: I thought the hands lugs of an Asian 7750 are 0.20mm compared to 0.25mm of an ETA 7750. Does this matter???

[frogfalls]

Great job and excellent tutorial!

Just I silly question How can I know that the watch is in 12pm and not 12 am before removing the hands?

Cheers

[bwhitesox]

@Skidbaecken this is the old slow beat 7750 so the hand sizes are the same as the ETA 7750.

You just wind the time through a few revolutions until you can see when the date changes to find out what time 12:00pm is.

[frogfalls]

@Skidbaecken this is the old slow beat 7750 so the hand sizes are the same as the ETA 7750.

You just wind the time through a few revolutions until you can see when the date changes to find out what time 12:00pm is.

Thanks bwhitesox!

[Skidbaecken]

what to do if you want to change a 28800 asian 7750 with a lug size of 0.20? the eta I have is for 0.25 hands but the hands on the rep obviously are fitted to the 0.20??

I guess most project with new reps will have this issue. Any experience?