RWG Technical

If I can find the time I will, there are so many variations on the Miyota copy, I do have some old Asian copies here, but not sure if they are the same models as in this model, or any of the newer ones out there... I dont' get any Asian copies in for service. RG

Here is a shot of the bezel/crystal removed for your reference. It's the 001 post that shows how to remove it...my mistake... Good luck, RG

Here you go Tom, all the answers you need are here... My subforum... The one you want is the How-to uncasing a 111, it is the basic same process, with the exception that you have to also remove the bezel and crystal to remove the movement. It comes out via the front on this model... You need a crystal press to re-install the bezel and crystal, so if you dont' have one, you may want to rethink taking it apart. RG

It depends on the model, some sit closer to the case, some don't. Most times, there is nothing that can be done to move it closer to the case, it's just the way it's built and the parts they happen to use that day... RG

Very nice, I like the end results, nice work as always... RG

Moving the seconds from 9 to 6 seems to put a lot of stress on the movement. The basic problem is that they took 5 gears to move it from 9 to 6, but could easily have done it with 3 gears. And to make it worse, the gears have no pivots, they sit flat against the movement bridges and have a LOT of friction... Until they use 3 gears, and install the gears with pivots and jewels, I would stay away from these models... RG

Is sounds like you have a sprung vs a fixed crown. With a sprung crown, there is a small spring in the crown and when you release the handle, it will spring out from the case - normal... If it's not sitting flat when the crown is pushed in, then the crown needs to reshaped so that it does. THe GMT function is on the second pull of the crown, not the third one, should be opposite the date set function, turn one way the date changes, turn the other, the GMT hand moves. GMT hand does 1 turn in each 2 turns of the main dial, if you set it to another time zone, it will not change the relationship between what you set it to, and your local time. But you have to use the GMT time zone ring to set the time, not the normal dial time... RG

Wonderful well done review as always... Thanks for taking the time to research and put the hours into these great posts of yours, so much appreciated. Happy Holidays... RG

20 grams for 10 pounds, a steal if it works. Super Lume is a about $30 a gram by comparison... No idea what it would be, maybe AF lume?? or Bergeron, or something else... RG

The new 7750 bearings are much bigger than the Asian ones, so replacement is not an option, at least not without some re-working of the Asian rotor. Although at $20 or so, the new ETA bearing is a wonderful improvement... The older ETA 7750's rotor bearings are the same size as the ones in the Asian models, but are held in place differently. As far as functionality goes, I have never had a failure of a 7750 rotor, the noise may be annoying, but it doesn't affect the working of the autowinder. You could replace the whole rotor and bearing with an ETA one, but the price is too high (the ETA rotor fits the new Asian 7750 and works just fine). Having worked in the aviation industry for 26 years, I have a hard time varying from the AMM, so if ETA suggests 9010 in a very small amount, that's what I do. What others do is their choice. I am not prepared to support putting a huge (in watch terms) blob of grease on a watch...others can suggest what they like, and it seems to work, so to each their own. If someone is weary of removing a caseback, I won't be the one to encourage them to bolb grease on the rotor, especially when the amount on the stick is as much grease I would use in mainspring barrels for about 30 watches...these are watches, not Mack trucks... Since my customers want their watches serviced and lubricated correctly, and want a long life from them after I do the work, I'll stick to what is tried and true. So far no returns or complaints... "nuff said... RG

Pulling the whole stack at once is not a standard practice, and there is a real risk of damaging the movement by pulling more than one hand at a time. Standard practice is to remove each hand in turn, if done correctly, there is no risk of scratches to the hands, there is a real risk of damage to the movement caused by the stress of removing all 4 hands at once. Simply hacking the movement at 12, and then installing the hands at 12 again, is not a realiable way to do any watch, especially a GMT model. You need to take more steps to ensure that the GMT hand lines up with the main ones, it's not a static installation but a dynamic one. There are many things to consider when installing hands, gear train, spacing etc...but that is all covered in basic watchmaking courses. RG

Yes, I can tell you that you should use axel grease where it's designed to be used, your car... A watch movement is a finely made mechanical marvel, it contains extremely small parts, and requires specialized oils and greases during servicing. Using anything but the manufacturer recommended practices, no matter the results, is not advised. If your scared to open the case, do yourself ( and your watch ) a favor, leave the axel grease to the automechanics, not inside your timepiece. There is a reason that ETA recommends the finest thinnest oil in a small amount on rotor bearings. Think about it. RG

The only difference is that there are 3 transfer gears moving the minute timer from 12 to 3. Given that these gears have no friction, the chrono seconds only activates the 30 minute timer every minute for a brief instant, there is no affect on the reliability...it's not a problem. My breakdown on the 7750 covers it in detail if you haven't read it already. RG

Well all I can add is that the ETA tech sheets all call for a small very small amount of Moebus 9010 on all rotor bearings... My only fear would be that some of the grease would get on something it shouldn't...otherwise I don't think it's a wear issue, as long as the rotor turns it should be fine... I am not one to vary from the standard practices, but that is just the way I approach things. RG

4 years of "Hey, when are you going to sell me that piece of junk old Rolex..." each and everytime I saw him... I think he finally wanted to shut me up. RG

Interesting comments... I bought this from the original owner, who bought the watch brand new in 1962...he had it serviced at the same place over the years, which was at that time an "Authorized Rolex Dealer"... From speaking to him, what you see in the pics, is what he bought in 1962. The bracelet was replaced at some point. The reason that the bracelet was replaced, is that this particular watch was used for diving, as this fellow is a scuba diver. Now note that for 25 years +, this watch was used in the salt waters of the north atlantic...and that is probably the reason for the damage to the bezel etc... however I think I will be able to clean it up and it will look good again... He changed the bracelet due to the fact the new bracelet has the fliplock part, and there is no risk of it opening up as your diving, the older bracelet did not have this option... As for the movement, from what he knows, it's original and the one that came with the watch... More pics, VERY dirty as you can see... Watch cleaning solution (no, it's not a urin sample, but looks like one...) BEFORE THE CLEANING... AFTER THE BATH in the ultrasonic machine, 30 minutes, with the heater on full... All dried off, and waiting for reassembly. I found a chunk of WOOD in the movement during disassembly (how that got there is beyond me) chunk in watch terms, small piece in non watch terms... Will update if it runs following assembly, I see no reason that it won't work... RG

Great comments, I have to try and find a correct bracelet to match it, otherwise, I'll go light on the rest, for now, as long as I can get it together, working, I'll live with the bad bezel and insert. Did this model have all polished case surfaces, or were the sides polished, and the top and bottom of the case brushed? I want to fix it up a bit, but want to keep in the original look of the watch. Should be a fun project. RG

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Wonderful work, so glad you did it yourself... Nice feeling isn't it? Congrats, RG

Impossible to know without looking at the watch in person. Date problems with a 7750 are not uncommon...brass washer I am not sure about, there is one on the hour wheel, but it should not be loose... RG

Well having serviced one, I can tell you that it is the most troublesome and difficult movement known to man... The cage with the escape wheel, balance, pallet etc...took me 10 (TEN) hours to assemble...very hard to work on to say the least... How much to service? If you can find someone, not cheap at all...I'll never do another unless it's by the hour... RG

It's not a 2888, that is the Date of Manufacture... The model number is never in that location, the model number was in the area to the left of the ETA mark, and it's missing as you can see where it was ground off... Looks like a 2846 to me, but it's a ETA not CN. RG

The tilting pinion is not disengaging from the center seconds chrono gear... It's out of adjustment or the spring has come disengaged...unless you have the experience and skills and tools, your best to take it to a watchmaker and have it fixed. For details on the tilting pinion, see the expert area, my subforum, towards the bottom, there are 3 7750 how it works posts, the tilting pinion is covered in detail. RG

Nice post, great to see all the correct tools, workmanship, skills, and an informative post with all the warnings for those that may attempt something like this themselves. Well done, I like to see quality craftmanship and attention to detail...great job, and nice photo's as well... RG

I didn't see the video, so it must have some other problem other than the normal jumpiness... RG