Seiko 7A38 - by the numbers

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Forum Home > Parts Info, Tech Tips and Tinkering > My 'patented' Pusher Circlip / C-clip Removal Tool

Seiko7A38
Site Owner
Posts: 9109

Some of you may have experienced problems removing 7Axx pusher circlips using the accepted traditional 2 screwdriver method. :mad:


This is what I use myself nowadays for removing the little b*ggers:




It really is as simple (both to make and use) as it looks. :)


It's just a cheap 1.2mm wide screwdriver (from an RS set, possibly) into the tip of which I have ground a U-shaped nick, using a Dremel Moto-Tool with a #409 cut-off wheel, which coincidentally happen to be precisely the correct width - 0.6mm, which is required. 


You simply press down gently with the two prongs of the tool onto the open ends of the circlip. It just pops off. No drama. No pinging.


March 11, 2012 at 8:25 AM Flag Quote & Reply

Sir Alan
Member
Posts: 451

Thanks Paul.


that picture explains all. Time to find a donor screwdriver.


My dremel is calling me ............

March 11, 2012 at 8:30 AM Flag Quote & Reply

Sir Alan
Member
Posts: 451

Well, I haven't made a tool yet, but something came to me tonite .....


I recently purchased (from ebay) the Seiko S-926 spring bar / bracelet tool:



it's a really nice bit of kit (as you would expect), but what you can't obviously see is what's underneath:



a varied collection of pieces - from pins (various lengths and diameters), screw driver bits and ...... a one with a groove. Hmmmmmmmmmm.


Well, I'm sure you can guess what I was thinking ;)


Fitting it to the tool, gave me this:



in close up:




so, it was time to try it out. And ........ it worked. That pesky lttle c-clip came off with a little ping (but I didn't lose it - it fell through the case and onto my work desk).


And this allowed me to finally remove the chrono pushers. Here's one each from my 7A38-7020 (the gold one at the top) and my practice 7A38-7190 (the stainless one at the bottom):





and in close-up (with springs and retainer removed):



and



and the relevant pieces:



the gasket on the gold one looks very new, I think this is why it wasn't moving as freely. The stainless gasket is much more worn.


I want to clean the parts (they really are very dirty) before putting them back together.


Can I put them straight into the ultrasonic cleaner? Will the gaskets be OK?


One final thing to note. On the stainless pushers, there was a retaining ring over the spring. The gold pushers don't have this ring.

So, when I dropped one, the spring pinged off and .............. disapeared forever (or at least for now). :roll:

 

March 14, 2012 at 6:38 PM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 9109

Yes, no problem with putting them in the ultrasonic cleaning tank, Simon - except be careful if any of your gold-plated pushers have plating which is starting to lift off, because the cleaning action will exacerbate it.


When I put stripped pushers in the tank, I don't drop them in directly, but suspend them in one of those cheap plastic / nylon tea strainers (with a slightly shortened handle). It's a lot easier to get all the tiny components (especially the springs) back out that way. ;)


The retaining ring as you refer to it, isn't a retainer per se - though it may sometimes temporarily hold the spring in place, by dint of the O-Ring seal being fatter than it's bore. It is simply a washer - Seiko p/n 81400829. If you go through the parts list / BOM on Seiko's database, you will find they are listed for almost every 7Axx. There are certain models, such as the 7A38-701x series, which because of a slightly different pusher design don't  use them, but as a rule, I find that most 7Axx's work better with them. Yes - like you I've also come across instances where they were completely missing (from models which should have them). I doubt this a manufacturing fault on Seiko's part. More likely evidence of prior tinkering by someone else. :roll: 


You may have noticed from your own photos that there are also two types of pusher seal used. The common or garden 7A's (for example 7A38-727x and 7A38-728x range) use what is effectively just an O-ring (p/n EG0060B01) whereas the Sports 100 / 150 models (like your 7A38-7020) use a proper miniature knife-edged gasket (p/n EC0060B0A). 


One last tip - when you reassemble them, resist the temptation to over-grease the pushers. A smear on the shaft is all you need. 

March 14, 2012 at 6:48 PM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 9109

I don't have many photos on file of pushers, but here are a couple that I prepared earlier. 8)


.... except be careful if any of your gold-plated pushers have plating which is starting to lift off ....


The three on the left are actually Orient J39 pushers, rather than 7A38. They didn't go in the ultrasonic tank. That' s how they were. :(




The one on its own on the right is a NOS Seiko p/n 80600703 (same as in your two-tone 7A38-7020), which I replaced them all with.

March 14, 2012 at 7:19 PM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 9109

A quick word about circlips. They are, no matter how careful you may be, prone to pinging off into space, never to be found again. :mad:

Some of the various part numbers used by Seiko include: 81400669, 81400683 and 83200271 (a substitute).

If you order 'genuine' Seiko Circlips, you can pay anything between £1.50 and £3.30 (+VAT) EACH for them ! :(


There are other subsitutes available, including these (Qty. 10), which you will often find coming up in your 7Axx searches on eBay:




Except that they don't actually appear to be 'QUALITY'. :roll: 


Far better to order these (Swiss-made by Eufors) - in a tube of 24 from Cousins. ;)


They're what I use myself - and price-wise, you know it makes better economic sense. :)

March 14, 2012 at 8:26 PM Flag Quote & Reply

nova
Member
Posts: 109

There is also the possibility to use a clip from

Seiko Kinetic 5M42 5M43

There it is used on the pusher for power reserve at 2 o clock.

June 28, 2012 at 1:13 PM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 9109

Some of the various part numbers used by Seiko include: 81400669, 81400683 and 83200271 (a substitute).


There are many different Seiko part numbers for the C-clips. 5M42 and 5M43 Kinetics use Seiko p/n 83200273.

These are available for £1.65 (+ VAT) each from Cousins UK, so it's a comparitively expensive substitute part. ;)

June 28, 2012 at 1:44 PM Flag Quote & Reply

Phil
Member
Posts: 145

Before I attempt the re-fitting of these clips - any advice ?, having taken them off, it looks like a devil of a job to put back. :roll:

August 2, 2014 at 5:51 AM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 9109

Put the circlip carefully back in place with tweezers. Having the slightest trace of silicone grease around the exposed end of the pusher shaft helps 'stick' it there. Make sure that the two open 'prong' ends of the circlip are correctly aligned with the groove machined in the shaft (which in some cases may require the pusher button depressing slightly). One confident downward push with a screwdriver blade on the central arc of the circlip. Spin the circlip through 180° to make sure it's seated properly. Easy-Peasy. 8)

August 2, 2014 at 6:08 AM Flag Quote & Reply

Phil
Member
Posts: 145

Much obliged Sir

August 2, 2014 at 6:10 AM Flag Quote & Reply

Khoi
Member
Posts: 2

Just found this very helpful thread and I'll be making a repair... not on a 7A38, but another quartz. Thanks guys. 

September 25, 2014 at 1:10 AM Flag Quote & Reply

CA

Posts: 58

Paul

Just making sure: Is the "groove" you mention the one at the end of the push-button as the clip doesn't stay in place... :(

Thanks

Claus

October 8, 2015 at 4:19 PM Flag Quote & Reply

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