GenTLe Posted October 26, 2014 Report Share Posted October 26, 2014 (edited) Finally I received all the needed greases and a correct movement holder for hands setting, so I decided to try the tear-down and reassemble of the "demoniac beast": Asian 7750 (a new spare one) Practically I'm following the ETA official oil chart, but in nearly the reverse order. First the movement fully assembled (without dial and hands): and without the day wheel. You can notice the wire-spring, that one is quite difficult to fit (already tried)... You also see the 2 levers that move the date and day wheels, and understand why you should NOT change the day/date with the stem when they are engaged. All the "clicks" of the day and date wheels are now gone, as like as the DDWs too: Date plate removed. Do you see that kind of "boomerang shaped" part near the center at h2? That's plastic, pure plastic. Movement rotated and autowind bridge removed. At hour 9 you can see the spring (straight line one) that prevent the main spring to be discharged through the autowind and counterweight Another little step: Chronograph bridge removed, at h12 there is the crown wheel and at h10 the ratchet wheel. Between h8 and h9, at the extreme left, the click spring. Winding gears removed: Barrel bridge gone too: A detail of the balance: Ready to remove the keyless : PS: the only little drops of oil were in the keyless, all the gears were running totally dry... Edited October 26, 2014 by GenTLe Quote Link to comment Share on other sites More sharing options...
GenTLe Posted October 26, 2014 Author Report Share Posted October 26, 2014 Now the questions: 1) I can't remove the 2nd and 4th wheels of the gear train because there is the driving pinion which looks forced on the 2nd wheel pinion. How can I solve this without bending the 2nd wheel? See here: 2) I removed the "Operating lever spring" (nr. 35 in the pic below), but I already foresee problems in fitting it back because I can't see how it fits between the barrel bridge and the main plate. Any suggestion / special instruction? 3) Day and date drive wheels: on the ETA charts there are "arrows" to indicate how they should be fitted. Any more precise sign? Special instructions? And finally: do you have some general suggestion? Something that I should carefully take care when reassembly? Thanks!! GenTLe Quote Link to comment Share on other sites More sharing options...
Rolexman Posted October 26, 2014 Report Share Posted October 26, 2014 1. Buy the specific tool or use hand lifters 2. When the top plate is assembled insert the side under the 'start-stop -arm (36) ' first. Than slightly bend with a small plier and slip underneath the 'reset arm'. Do so before installing the auto wind plate (34). 3. Align to intermediate wheel post according to arrows. 4. Good luck. Disassembling is the easy part Quote Link to comment Share on other sites More sharing options...
GenTLe Posted October 26, 2014 Author Report Share Posted October 26, 2014 Thanks Rolexman About the "1" question: I mounted the plate on a mvmnt holder and pushed the pinion from the datewheel side with a sharp tweezer: it came out About the "3", I've found this nice pic over RWI Quote Link to comment Share on other sites More sharing options...
ceejay Posted October 27, 2014 Report Share Posted October 27, 2014 The ETA labs flash animation may help you along also if you don't already have it/seen it? Good luck Sent from my iBend 6 Quote Link to comment Share on other sites More sharing options...
GenTLe Posted October 27, 2014 Author Report Share Posted October 27, 2014 The ETA labs flash animation may help you along also if you don't already have it/seen it? Good luck Sent from my iBend 6 Yes Only at the end of the disassembly, but it helped for the stuck gear Thanks CJ Quote Link to comment Share on other sites More sharing options...
kbh Posted October 28, 2014 Report Share Posted October 28, 2014 That plastic piece that you mentioned at the beginning, the hour counter lock. Can that be replaced with a genuine ETA piece? I think thats whats hanging up one of my 7750's where the hour hand won't reset. Any of you experts have knowledge of that? Quote Link to comment Share on other sites More sharing options...
GenTLe Posted October 28, 2014 Author Report Share Posted October 28, 2014 (edited) That plastic piece that you mentioned at the beginning, the hour counter lock. Can that be replaced with a genuine ETA piece? I think thats whats hanging up one of my 7750's where the hour hand won't reset. Any of you experts have knowledge of that?Probably yes. And in any case the cost of the gen one (not counting the horologist cost) is low enough to try it. Anyway that plastic part only acts as a brake, avoiding the hour register hand to move around when chrono is not engaged. I'd look somewhere else (like the levers connected to the reset button) if the problem is that it doesn't reset. Edited October 28, 2014 by GenTLe Quote Link to comment Share on other sites More sharing options...
kbh Posted October 28, 2014 Report Share Posted October 28, 2014 Somewhere in another thread I had heard from others with the same problem that it was caused by that plastic piece. Maybe it's holding the chrono from resetting, if that's possible. I don't know enough about 7750's to make an educated guess. As it is I just let the hour hand go all the way around and then stopped it on zero. But it still annoys me when I have a watch that doesn't work correctly. If it was that, it looks like a relatively simple fix. Quote Link to comment Share on other sites More sharing options...
GenTLe Posted October 28, 2014 Author Report Share Posted October 28, 2014 Somewhere in another thread I had heard from others with the same problem that it was caused by that plastic piece. Maybe it's holding the chrono from resetting, if that's possible. I don't know enough about 7750's to make an educated guess. Nope, if you look at the pic upper it does the opposite: it is tied, with the upper plastic arm, to the reset lever. When you reset the chrono the metallic lever goes against the cam below the hour register gear forcing it to rotate, and simultaneously moves the brake far from the same gear. In other words, you need to disassemble the movement to understand what's wrong and only after you can get the proper replacement (maybe you only need to reassemble it properly even not changing anything) Quote Link to comment Share on other sites More sharing options...
GenTLe Posted November 14, 2014 Author Report Share Posted November 14, 2014 Rebuild completed There the shots, hope that they'll be useful to someone and that our Horologist can check them and tell me what I have done wrong (if mistakes are present). Side note: some shots have been taken before I absorbed with some absorbing paper the excess of oil when it happened. First of all, my new tray, very confortable to fit the parts divided by sectors. Here with the 7750 fully unassembled. I used to piece of paper not to mix the plate and balance incablocs. The main plate, clean and ready to receive the parts: Et voitlà: keyless up! The other side of the plate, with the pallet fork, already with its Moebius 9415 on a pallet stone Up the balance and its [censored], and already oiled the jewels around (HP 1300 for the slow gears, 9010 for the fast ones) Measuring the running second pinion: Up the barrel and the gear train. Later on I substituted the barrel with a gen ETA one: it fits perfectly Up the barrel bridge. I put a bit of Molycote DX Litium grease also on the crown wheel to make the handwind smoother Starting to assemble the chronograph parts: Up the chrono bridge. On the left is visible the autowind click. When it get out of place the watch can't be autowound because the counterweight act as a discharge disc... A particular of the chrono reset hammers, with the tiny layer of Molycote DX grease on them A particular of the tiny oscillating pinion, a bit difficult to make it goes in place Chronograph part nearly ready (reverse gear and reset hammers still not in place) to receive the autowind bridge... ...and with autowind bridge installed Movement rotated to the other side, with day/date change gears (on the left) and hour chrono register (on the right) and it's reset system. That little spring on the right is pretty difficult to fit... A side view with the pinions exposed. The finishing at these magnifications looks so weird... Up the calendar bridge/platform: Here an interesting detail. on the left/up the gen ETA double corrector, on the right/down the asian one. Both have a kind of clutch system (the washer spring), so in both cases it you try to change the day/date with the day and date drive wheels engaged, the clutch will prevent damages: Everything UP except the day wheel. Near to nr. 19 on the DW you can partially see another spring which is not that easy to fit, now covered by date jumper maintaining plate: Completed! It is now running (with chrono engaged) since 14 hours. This evening I will recharge it and let it another day running upside down, and then within 2 days I'll calibrate the 2 chrono springs that need it and the balance to go nearest possible to COSC. In the end it's not so "demoniac" as one could thing. The only thing that scares me about this movement is the removal and placement of the hands, especially the chrono center second, which I managed to split from its tube when I disassembled it first... Cheers, GenTLe Quote Link to comment Share on other sites More sharing options...
kbh Posted November 14, 2014 Report Share Posted November 14, 2014 NIce job. You're my new idol! Quote Link to comment Share on other sites More sharing options...
Guest Posted November 14, 2014 Report Share Posted November 14, 2014 Very dumb question but all are the screws in the movement the same size? Quote Link to comment Share on other sites More sharing options...
krpster Posted November 14, 2014 Report Share Posted November 14, 2014 Well done! Looks like a very successful and education project for you. Quote Link to comment Share on other sites More sharing options...
GenTLe Posted November 14, 2014 Author Report Share Posted November 14, 2014 (edited) NIce job. You're my new idol! Well done! Looks like a very successful and education project for you. Thanks! Indeed educational (for me at least ) Very dumb question but all are the screws in the movement the same size?Nope, 3/5 different ones Edited November 14, 2014 by GenTLe Quote Link to comment Share on other sites More sharing options...
Rolexman Posted November 14, 2014 Report Share Posted November 14, 2014 Great job putting her back together and taking the time to do a write up BUT!.... I strongly advice that no one uses the pictorial as a reference for oiling as LITERALLY all oil/grease is applied in the wrong place in the pictures I have seen. I don't have the time for making detailed comments but I suggest you keep on practicing and reading. Especially the oiling part: the location and amounts are crucial for a stable and reliable movement. Keep it up! Quote Link to comment Share on other sites More sharing options...
GenTLe Posted November 14, 2014 Author Report Share Posted November 14, 2014 Rolexman, as I'm still learning (and I've followed the età chart), can you help me telling me about how can I correct my technique? I'd be really grate to you! Quote Link to comment Share on other sites More sharing options...
billyfras Posted December 2, 2014 Report Share Posted December 2, 2014 Man im trying to be like you right now Gentle. I'm in the middle of my first teardown. Its going really slowly however. Quote Link to comment Share on other sites More sharing options...
ceejay Posted December 2, 2014 Report Share Posted December 2, 2014 Well I have started too, I have a ETA 7750 stripped and ready to go through the cleaning machine tonight. I am having trouble locating Jismaa 125 lube. Is there a alternative? Quote Link to comment Share on other sites More sharing options...
GenTLe Posted December 2, 2014 Author Report Share Posted December 2, 2014 (edited) Well I have started too, I have a ETA 7750 stripped and ready to go through the cleaning machine tonight. I am having trouble locating Jismaa 125 lube. Is there a alternative? In the animation the Jisma 125 is used only for the dring pinion which, in the eta chart, is replaced by Molycote DX For Jismaa 124, the alternative is Moebius 9501 Anyway, if you download the latest Eta lubrification charts, there's no Jismaa/9501 for the 7750 (it's only in the 2836 and 2824 cannon pinion with driving wheel) Edited December 2, 2014 by GenTLe Quote Link to comment Share on other sites More sharing options...
GenTLe Posted December 2, 2014 Author Report Share Posted December 2, 2014 Man im trying to be like you right now Gentle. I'm in the middle of my first teardown. Its going really slowly however. Take care when placing the automatic device bridge: the oscillating pinion tends to disengage from the "clutch 60 s, 2 functions" and then, when you screw the automatic dev bridge you risk to break the oscillating pinion... Quote Link to comment Share on other sites More sharing options...
ceejay Posted December 2, 2014 Report Share Posted December 2, 2014 Ahh yes, thanks. Kluber 125 breaking grease & epilame treatment on the keyless. That's going to hurt the wallet! Sent from my iBend 6 Quote Link to comment Share on other sites More sharing options...
GenTLe Posted December 2, 2014 Author Report Share Posted December 2, 2014 Ahh yes, thanks. Kluber 125 breaking grease & epilame treatment on the keyless. That's going to hurt the wallet! Sent from my iBend 6 Ah yes... Plus the main spring winder, 'cause without it you simply can't reassemble the main spring... About the Fixodrop, I got it (5cc) from here: http://www.ebay.co.uk/itm/Moebius-8941-Fixodrop-Pour-epilamage-For-epilame-2-5-5-ou-10-ml-a-choisir-/400280543549?pt=FR_MaisonJardin_Horloges&var=&hash=item5d3294613d Quote Link to comment Share on other sites More sharing options...
GenTLe Posted December 3, 2014 Author Report Share Posted December 3, 2014 (edited) Finally: before mounting the autowind bridge have 1 liter of chamomile ... Yesterday 1.30h to mount that bastard... Once the oscillating pinion was going out, another time the reverse gear was moving, then the hammers, maybe all ok but the hour pinion was not in the jewel... AAAAAHHHHHHH!!!!!!!!! Edited December 3, 2014 by GenTLe Quote Link to comment Share on other sites More sharing options...
GenTLe Posted February 12, 2016 Author Report Share Posted February 12, 2016 On 11/14/2014 at 7:46 PM, Rolexman said: Great job putting her back together and taking the time to do a write up BUT!.... I strongly advice that no one uses the pictorial as a reference for oiling as LITERALLY all oil/grease is applied in the wrong place in the pictures I have seen. I don't have the time for making detailed comments but I suggest you keep on practicing and reading. Especially the oiling part: the location and amounts are crucial for a stable and reliable movement. Keep it up! I think now I got what was wrong there... They (ETA) show to put the oil in the INNER site of the jewel, which is a crazy thing (see below). I never used that movement until now, and I'm re-servicing it. I see my noobyness also because I heavily over-oiled all the keyless parts there... 1 Quote Link to comment Share on other sites More sharing options...
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