Hello everybody,
Even though this is my 4th year in the forum, this is just my first thread. I have been sitting quiet in a corner, listening to stories....
Three years ago i bought an H Factory Pam089. The movement has been more than reliable, apart from a few issues, over the years, with the auto winding system (2 times I had to replace broken gears). This time it was more serious since it kept stopping for a few minutes and then start again.
I am fed up with watchsmiths not want to repair my watches (I do understand them though, since asian movements seem to be more fragile and there are no available parts) and when they do they dont really care about the end result (I had a pam crown & guard completely damaged by a watchsmith in the past and all he said was that this is a replica why do you care how it looks like!!!!). So I decided to repair it myself. It wasn't the first time, I had a, few tries with A7750s & 6947s in the past.
When I opened it, I noticed that it was very dirty in there, there were even broken screws!! I guess that was the reason it kept stopping.
I started taking it apart and I found a few "bad" gears but I managed to cause more damage (freaking amateurs messing with watch movements!!!!!). I broke the escape wheel!!! I ordered some original ETA 7750 parts from Cousins (including the escape wheel). Everything fit (yes!!!) apart from the escape wheel (damn)!!!!!
After realising that sourcing parts for asian movements is almost impossible and since my never oiled A7750 GMT was in a bad condition, I email my TD to ask to buy a new A7750 GMT. I was schocked to find out that the price was $215 shipped so I decided to do a little experiment. Transform a normal A7750 into an A7750 GMT.
I did quite some research but I couln't find any info on that. There are tons of info on the A7750 Chrono but none on the GMT! I only managed to find some pics of the calendar platform, nothing else.
I bought a Chinese 7750 from Cousins (3LZF2 - part no CH3LZF2M) for $185, which still is not cheap but I was curious to see if there are any differences, if its oiled, for example. It turned out that it was just like the one I had and while taking it apart I couldn't identify a single drop of oil. I am not experienced though, but apart from tiny bits of dirt (see photo) there wasn't anything that looked like oil.
From the info & photos I found online, I came to the conclusion that the only difference between the two movements was the calendar platform and that all I had to do is to install the old one into the new movement. Well, that wasn't the case!!! I realised it the hard (but more fun) way that there are enough differences between the two movements that you have to completeley strip them down in order to do all the necessary changes.
First, the Calendar Platform is different. There is no day wheel and in the centre of the plate there is space for an extra wheel for the GMT hand (see photos).
Second, the Main Plate is different!!! The GMT one has space for an extra gear (jeweled) that rotates the GMT hand (see photos). That difference alone means that the only reason to buy a new A7750 (to use in a pam gmt) is just to use as parts.
Third, the Second Wheel needle is longer in the GMT version! I found that out after the whole movement was assembled so I had to take everything apart again!
Fourth, the Setting Level Jumper is different. The GMT version has a small stopper that restricts the Double Corrector's movement so it can be used to set the GMT hand (see photo). I found that out after most of the movement was assembled so I had to take everything apart again (2nd time)!
Fifth, the chrono one has many levers for the chrono functions that had to be removed since there is no use for them.
You have to have both movements completely stripped down, use all the parts of the new one (apart from the ones mentioned above, which should be cleaned and used from the old movement), add some extra virgin olive oil following the ETA oil charts (you can easily find them online) and bake for about 20 hours!!! This is how long it took me since I had to do the whole thing 3 times (seconds wheel & setting level jumper)!!! Also I had to oil everything, hence I spend hours reading the charts and tutorials.
Anyway, my pam has now a new, freshly oiled (though I am not really sure that I have used the right amounts of oils, anyway I guess it will be better that nothing) movement and two days now its doing great. I haven't regulated it and the first day it gained 15 minutes!!! I guess its magnetised but don't have a demagnetizer. I set the time last night and now it seems to work properly.... It could be loosing or gaining some seconds but I can't really tell. Does that make sense? I haven't demagnetize it.
A few more things to point out for nubies like myself. Be extremely cafeful when you install the Barrel Bridge, the Escape Wheel can break sooo easily. Do not try to remove the Balance Wheel Shock Absorbers (as ETA proposes), you'll break them, at least I did! Read carefully the tutorials and then start working on the movement. Always discharge the Main Spring before doing anything.
I found the following tutorials more than helpful, especially the one from "14060 or 16610" who is working on an A7750 and not an ETA one.
https://forum.replica-watch.info/vb/showthread.php/52351-What-Does-an-A7750-Look-Like-Disassembled
http://www.watchrepairtalk.com/topi...alkthrough-the-industry-standard-chronograph/
Hope I managed to answer some of other members questions regarding the same subject. I know mine are answered....
Thanks for reading.
Even though this is my 4th year in the forum, this is just my first thread. I have been sitting quiet in a corner, listening to stories....
Three years ago i bought an H Factory Pam089. The movement has been more than reliable, apart from a few issues, over the years, with the auto winding system (2 times I had to replace broken gears). This time it was more serious since it kept stopping for a few minutes and then start again.
I am fed up with watchsmiths not want to repair my watches (I do understand them though, since asian movements seem to be more fragile and there are no available parts) and when they do they dont really care about the end result (I had a pam crown & guard completely damaged by a watchsmith in the past and all he said was that this is a replica why do you care how it looks like!!!!). So I decided to repair it myself. It wasn't the first time, I had a, few tries with A7750s & 6947s in the past.
When I opened it, I noticed that it was very dirty in there, there were even broken screws!! I guess that was the reason it kept stopping.
I started taking it apart and I found a few "bad" gears but I managed to cause more damage (freaking amateurs messing with watch movements!!!!!). I broke the escape wheel!!! I ordered some original ETA 7750 parts from Cousins (including the escape wheel). Everything fit (yes!!!) apart from the escape wheel (damn)!!!!!
After realising that sourcing parts for asian movements is almost impossible and since my never oiled A7750 GMT was in a bad condition, I email my TD to ask to buy a new A7750 GMT. I was schocked to find out that the price was $215 shipped so I decided to do a little experiment. Transform a normal A7750 into an A7750 GMT.
I did quite some research but I couln't find any info on that. There are tons of info on the A7750 Chrono but none on the GMT! I only managed to find some pics of the calendar platform, nothing else.
I bought a Chinese 7750 from Cousins (3LZF2 - part no CH3LZF2M) for $185, which still is not cheap but I was curious to see if there are any differences, if its oiled, for example. It turned out that it was just like the one I had and while taking it apart I couldn't identify a single drop of oil. I am not experienced though, but apart from tiny bits of dirt (see photo) there wasn't anything that looked like oil.
From the info & photos I found online, I came to the conclusion that the only difference between the two movements was the calendar platform and that all I had to do is to install the old one into the new movement. Well, that wasn't the case!!! I realised it the hard (but more fun) way that there are enough differences between the two movements that you have to completeley strip them down in order to do all the necessary changes.
First, the Calendar Platform is different. There is no day wheel and in the centre of the plate there is space for an extra wheel for the GMT hand (see photos).
Second, the Main Plate is different!!! The GMT one has space for an extra gear (jeweled) that rotates the GMT hand (see photos). That difference alone means that the only reason to buy a new A7750 (to use in a pam gmt) is just to use as parts.
Third, the Second Wheel needle is longer in the GMT version! I found that out after the whole movement was assembled so I had to take everything apart again!
Fourth, the Setting Level Jumper is different. The GMT version has a small stopper that restricts the Double Corrector's movement so it can be used to set the GMT hand (see photo). I found that out after most of the movement was assembled so I had to take everything apart again (2nd time)!
Fifth, the chrono one has many levers for the chrono functions that had to be removed since there is no use for them.
You have to have both movements completely stripped down, use all the parts of the new one (apart from the ones mentioned above, which should be cleaned and used from the old movement), add some extra virgin olive oil following the ETA oil charts (you can easily find them online) and bake for about 20 hours!!! This is how long it took me since I had to do the whole thing 3 times (seconds wheel & setting level jumper)!!! Also I had to oil everything, hence I spend hours reading the charts and tutorials.
Anyway, my pam has now a new, freshly oiled (though I am not really sure that I have used the right amounts of oils, anyway I guess it will be better that nothing) movement and two days now its doing great. I haven't regulated it and the first day it gained 15 minutes!!! I guess its magnetised but don't have a demagnetizer. I set the time last night and now it seems to work properly.... It could be loosing or gaining some seconds but I can't really tell. Does that make sense? I haven't demagnetize it.
A few more things to point out for nubies like myself. Be extremely cafeful when you install the Barrel Bridge, the Escape Wheel can break sooo easily. Do not try to remove the Balance Wheel Shock Absorbers (as ETA proposes), you'll break them, at least I did! Read carefully the tutorials and then start working on the movement. Always discharge the Main Spring before doing anything.
I found the following tutorials more than helpful, especially the one from "14060 or 16610" who is working on an A7750 and not an ETA one.
https://forum.replica-watch.info/vb/showthread.php/52351-What-Does-an-A7750-Look-Like-Disassembled
http://www.watchrepairtalk.com/topi...alkthrough-the-industry-standard-chronograph/
Hope I managed to answer some of other members questions regarding the same subject. I know mine are answered....
Thanks for reading.
