RWG Technical Posted March 1, 2009 Report Share Posted March 1, 2009 Servicing and teardown of a 4 year old Asian 7750 21.6K model. A long time ago, in a land far away called RWG (the original RWG) Quote Link to comment Share on other sites More sharing options...
billywhiz Posted March 1, 2009 Report Share Posted March 1, 2009 Nice write up The Zigmeister, I too got a 196 from the same era ( $388 from Josh ) - just stopped after many years faithfull service - , dunno whats up with it - second hand runs fine but main hands don't turn - knacked pinion I think somewhere - another one destined for the scrap heap > no-one in EU to service / repair these. Quote Link to comment Share on other sites More sharing options...
szvwj Posted March 1, 2009 Report Share Posted March 1, 2009 Nice writeup, thanks for the info! Quote Link to comment Share on other sites More sharing options...
1976 Posted March 1, 2009 Report Share Posted March 1, 2009 Very nice review,very informing,keep up the good work. Best regards Quote Link to comment Share on other sites More sharing options...
DemonSlayer Posted March 1, 2009 Report Share Posted March 1, 2009 Thanks for the indepth analysis The Zigmeister. Its from helpful articles like these which has convinced me that servicing your loved watches is a must if you want them last. I know a lot of people say just get the movements replaced, but I don't think theres any guarantee you will be able to find replacement movements when the current one burns out... Makes more sense to me to have the movement currently installed into your watch regularly serviced as a preventative measure, to ensure it runs and keeps beautifully for many years. Quote Link to comment Share on other sites More sharing options...
By-Tor Posted March 1, 2009 Report Share Posted March 1, 2009 Thanks mr. Zinedine Zidane... oops, mr Ziggy Zumba for another fine article. 5. The general consensus that the older or even the newer Asian 7750’s are junk and won’t last a lifetime – even if serviced – is false. This myth apparently dies hard. And if you think about how few bad reports there are of the new A7750, I think the Chinese have really managed to put out a decent chronograph movement. No need to avoid A7750 at all. All of my high beat 7750's have always functioned perfectly, without any problems. Quote Link to comment Share on other sites More sharing options...
Mickey Padge Posted March 1, 2009 Report Share Posted March 1, 2009 Top stuff, very interesting read and great pics, thanks! Quote Link to comment Share on other sites More sharing options...
scoobs1971 Posted March 1, 2009 Report Share Posted March 1, 2009 Much interesting as always! Thnx, RG Quote Link to comment Share on other sites More sharing options...
Chicken Manny Posted March 1, 2009 Report Share Posted March 1, 2009 Excellent post The Zigmeister! I wondered about how these would hold up and this post sets the record straight. Thank you! I thought the pushers were sealed on these models but it appears dirt is making its way in to the case. Is that normal? Now that dry cap jewel has me thinking it's time to service some watches. Quote Link to comment Share on other sites More sharing options...
Toadtorrent Posted March 1, 2009 Report Share Posted March 1, 2009 That was tops The Zigmeister. Thanks for doing this. Remember folks...this is an ultimate test as this watch was run continuously for 4 years...and NOT as part of an 80 watch collection rotation!!! Great photos!! I'm still waiting for that book of yours. Quote Link to comment Share on other sites More sharing options...
Shundi Posted March 1, 2009 Report Share Posted March 1, 2009 Amazingly detailed pics, description, and overall breakdown- The Zigmeister's teardown's make some of TZ's finest look like rushed amateurs... very impressive and you conclusions on the movement represent a big step in the reliability and service life of Asian movements. Thank you!! Quote Link to comment Share on other sites More sharing options...
SportsterRider Posted March 1, 2009 Report Share Posted March 1, 2009 Excellent writeup. It's hard to find this type of article in a paid subscription magazine - to see it here is another example of how great this site and it's members are! Thanks The Zigmeister! Quote Link to comment Share on other sites More sharing options...
RWG Technical Posted March 1, 2009 Author Report Share Posted March 1, 2009 The pushers and the stem are indeed sealed with o'rings. I will be taking them apart and replacing all the o'rings and applying new silicone. I think some of the dirt entered through the stem or pushers, and some of the dirt was from the gears wearing and seating into each other. The one picture where the great and 3rd wheels meet leads me to believe that the wheel to pinion rotation was responsible for the particles. Every watch "breathes" so to speak, when worn the case heats up and with it the air inside...warm, expanded it tries and does escape - if only slightly - past the seals. When taken off, the reverse happens, as it cools it sucks in ever so slightly some air and particles from the outside... Thanks for the feedback, the "book" is a ways down the road, when I find the time RG Quote Link to comment Share on other sites More sharing options...
freddy333 Posted March 1, 2009 Report Share Posted March 1, 2009 Brilliant post, Ziggy! :good: A couple of comments - MODEL: Asian 7750, 21,600 BPH (yes, this is the so called Quote Link to comment Share on other sites More sharing options...
clkcadet Posted March 1, 2009 Report Share Posted March 1, 2009 Awesome write up! Wow Quote Link to comment Share on other sites More sharing options...
brook0 Posted March 1, 2009 Report Share Posted March 1, 2009 Fantastic post!!! A watch repair clinic in one post. Quote Link to comment Share on other sites More sharing options...
RWG Technical Posted March 1, 2009 Author Report Share Posted March 1, 2009 Why not replace the mainspring while you have everything apart? I would replace the mainspring and normally do as part of a service. Because the ETA 7750 runs at 28.8K, not at 21.6k, the mainspring is not compatible. The only mainsprings I can buy are ETA ones designed and made for the 28.8K models. The faster beat mainspring would have a higher denison strength than the slower beat one. Having said that, I have not tried the ETA spring in the slower beat movement to test it out, but it's a known that faster beats need more powerful mainsprings. Once clean and oiled, the rate over 24 hours static (not winding the movement) is within a few seconds, so it doesn't seem to be affecting the movement keeping the old spring in place. RG Quote Link to comment Share on other sites More sharing options...
lanikai Posted March 2, 2009 Report Share Posted March 2, 2009 No doubt that having you service my movements have made a HUGE difference in performance.. thank you Ziggy,.. that was a whole lot of time just to post this.. but worth all of it us.!! Cheers L Quote Link to comment Share on other sites More sharing options...
AllergyDoc Posted March 2, 2009 Report Share Posted March 2, 2009 Fabulous and interesting write up and pics. Quote Link to comment Share on other sites More sharing options...
nakortheblue Posted March 2, 2009 Report Share Posted March 2, 2009 Just curious, does this mean that watches that don't get used will not gum up do fast? I'm asking because someone selling watchwinders claimed that watchwinders extend the life of the watch. That was tops The Zigmeister. Thanks for doing this. Remember folks...this is an ultimate test as this watch was run continuously for 4 years...and NOT as part of an 80 watch collection rotation!!! Great photos!! I'm still waiting for that book of yours. Quote Link to comment Share on other sites More sharing options...
phaedo Posted March 2, 2009 Report Share Posted March 2, 2009 Brilliant analysis and write up, it certainly furthers the cause for how reliable these movements really can be when properly serviced. Makes me think I should get mine serviced... Quote Link to comment Share on other sites More sharing options...
Ztech Posted March 2, 2009 Report Share Posted March 2, 2009 Awsome write up Rob. Thanks for sharing. Quote Link to comment Share on other sites More sharing options...
RWG Technical Posted March 2, 2009 Author Report Share Posted March 2, 2009 Just curious, does this mean that watches that don't get used will not gum up do fast? I'm asking because someone selling watchwinders claimed that watchwinders extend the life of the watch. Time is the factor. The oils will interact with the air and dry out and turn acidic, no matter if the watch is running or sitting still. Obviously if you never wind the watch it will never suffer any damage, but the key has always been to service the watch every 5 years or so to replace and remove the old lubricants. The oils also stay in their respective locations due to capillary action, unlike a car engine, the oils don't settle or need to be moved around by having the watch run for proper lubrication to take place. RG Quote Link to comment Share on other sites More sharing options...
StormTooper4 Posted March 2, 2009 Report Share Posted March 2, 2009 Staggeringly wonderful photos, and a brilliant write up, much went over my head but I very much appreciated the read. Thank you for your time and effort that went into sharing this ST4 Quote Link to comment Share on other sites More sharing options...
valerian Posted March 2, 2009 Report Share Posted March 2, 2009 Fantastic information, thank you very much, The Zigmeister! I'm a bit unsettled though: Been to my AD with a recently purchased Gen IWC (cal. "7922", enhanced 7750) that was running since 2004. It keeps time very accurately (-1/+1 sec when placed face down at night). The lady at the AD told me that no service was needed. They only recommend service when the watch performance gets out of line. No regular service for gen movements then? Any thoughts on this? Yours kindly Valerian Quote Link to comment Share on other sites More sharing options...
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