Seiko 5M43/5M42 Movements

[bobm12]

Hi all,

 

I figure these movements were kind of popular and expensive (they are still available). So, since I just saved US$104, the price of them this side of the pond (take or leave a few dollars) I wanted to share my experiences.

 

First off, the service data:

 

233_Seiko5M42A,5M43A.pdf

 

Now for the disassembly:

 

My order here is a little odd. The movement was in bad shape being an ebay non working watch, just for the exercise at hand. Therefore, sometimes in order not to damage a part, i.e. circuit or coil mainly, other parts are being taken out of the way first to facilitate the disassembly. In some pictures, there is another similar movement which also was used to eventually put together a working one between the 2.

 

So, here is the 5M42, notice that the 5M43 only adds the day disc, a selector gear we'll mention later and a disc holding clip. Everything else is the same. The new capacitor kit that replaced the bugged original one is: 30235MZ which is also good for the following movements:5M62 and 5M63.

 

 

 

There is no capacitor present in this movement...

 

 

Notice that this movement can be disassembled each side without interfering with the other side. This means that we can remove all the parts from one side and then turn it and remove all the parts from the other side. Your choice which side you want to start first. I prefer to remove the rotor and keep going on that side (bottom) to ensure there is no damage to the rotor screw and bearings. As an added advantage, I'm also minding the coils and circuit.

 

 

I would have removed the capacitor clamp, insulator and capacitor unit. This is only possible after the previous step and before the one being illustrated below. 

 

Removing the circuit block cover:

 

 

I also removed the oscillator weight (rotor) bridge first since the circuit seemed kind of stuck and wanted more visual/elbow room to tackle it:

 

 

A closer view of this bridge, notice the intermediate wheel for generating rotor:

 

 

 

Now we have a full view of the electronics, in very delicate estate I may add. Luckily the circuit block is OK ( I used the one from the other movement which was in better shape ):

 

 

Then, goes the short coil...and the long coil, the generating rotor and generating stator:

 

 

 

 

We remove the only screw holding the train wheel bridge and look under the "hood":

 

 

Here is the underside of the train bridge. You are seeing the setting wheel still stuck to the bridge:

 

 

In the following pictures we remove the fifth wheel and pinion, fourth wheel and pinion, third wheel and pinion, step rotor, minute wheel, center wheel and pinion...

 

 

 

 

 

Then we proceed to the keyless work et al. Removing the train wheel setting lever, switch lever (careful is under tension), setting lever, capacitor connection and yoke:

 

 

 

 

We discover underneath the clutch wheel and remove it. Also the rotor stator is removed:

 

 

 

 

At this point we turn over the movement...or what is left of it:

 

 

As you see this one is the 5M42 version without the day disc feature. Normally for the 5M43 we pry, carefully with a small screwdriver, the snap for day star for dial disk, the day star with dial disc and the intermediate wheel for day correction. All those parts are similar in shape and location as to the 7S26 mechanical movement so there is no need to illustrate it at this point...if we had gotten it. Note that this movement uses a dial washer.

 

So we skip the day star and start removing the date dial guard and date dial:

 

 

Underneath is the familiar date jumper reminiscent of the Seiko mechanical movements, date driving wheel, intermediate wheel for calendar correction, date correction setting wheel, and hour wheel. I'm not sure about the plate present in this movement, it might have been one of those franken things, but this plate doesn't have the non-removable antimagnetic shield plate. I used the donor movement main plate since it had it.

 

 

Here is a picture of the movement using the antimagnetic plate:

 

 

So removing each mentioned part:

 

 

 

 

 

And voila! The bare plate:

 

 

Now we only need to remove the holding ring for dial and dunk everything in the cleaner...NOT everything! The generating rotors, both coils and circuit block DON'T go in the cleaner! Nor would go the capacitor if we had one in this case. Everything else is fair game. One note of caution, while assembling use plenty of rodico for each part since magnetism is an issue and can attract undesirable particles into the movement. Always check and recheck!

 

 

From this point on and after cleaning the parts. Assembly is simply a reverse order. Follow the technical data for lubrication...I simply used moebius quartz oil and simplified everything...and maybe a little Seiko S6 here and there, mainly keyless works.

 

One important data for those who don't have a multimeter and want to check the coils. You are measuring 2 different ranges of resistance/impedance, if your meter is not autoranging, make sure to change the range accordingly.

 

Here is the final product in its case and with temporary hands...until I get something I really like and can refinish the case.

 

 

 

I also forgot to say that this movement uses hands: 65/110/20...so far difficult to find in sport, luminic types...or so it seems from trawling the net!

 

Hope all this helps! Enjoy!

 

Cheers,

 

Bob

 

PS. Any insight, corrections, suggestions, etc is most appreciated!

 

 

 

 

[icius]

Bob, nice walkthrough. Looks almost identical to the 5M62 that started me down this slippery slope.

[bobm12]

That's correct icius, I believe that's the name for the same movement by Pulsar, a Seiko division. Thank you for the nice words!

 

By the way I'm editing the above to add something I forgot!

 

Cheers,

 

Bob

[Ishima]

And this is why kinetic service prices usually aren't cheap. 

Watch looks nice as it is, but I wouldn't mind seeing it refurbished with your final choice of hands.
Very interesting, thanks for the post, bob.

Edited April 6, 2015 by Ishima

[Geo]

I echo Ishima's words Bob!

Very informative, and thanks for taking the considerable time to photograph and document the journey. :)

[bobm12]

Thank you guys, I appreciate your nice words!

 

Cheers,

 

Bob

[Nigel2085]

Hi Bob,I wonder could you help me please, my watch was working OK but thought it was about time after 10 years to give it a service

Seiko wanted about £100 to give it a service 

I am not very well versed in watch repair but thought after seeing your guide I should be able to do it

I removed the train wheel bridge but cannot get it back on the wheels just wont line up, spent 2 days on it but not getting any where

Took watch to a watch repairer but now I have taken it apart they wont touch it

could you possibly give me any hints on how to get the bridge back on

I don't want to as I am attached to the watch, but if I cant get it back together, will put it on ebay for spares repair

 

Many thanks Nigel (UK)

[rogart63]

What  a great job you have done Bob :)  . Lots of small parts in that movement! Interesting movement with rotor and electronic parts. It's like a mix between an automatic and a quartz? 

[bobm12]

@nigel: All I can say Nigel is don't despair and have lots of patience. Make sure the wheels are perfectly aligned on the bottom plate before you attempt the upper bridge, be gentle and test often. Tiny parts and small pivots...still quite resilient for the size but not bullet proof so they can be broken and rendered useless...so care and patience is the recipe!

 

@rogart: That's correct rogart, the mechanical section of the movement resembles in principle an auto movement, with weight and all that turns a tiny motor which in turn charges the capacitor. It all boils down to provide electricity to the quartz that makes this type of watch very precise. I particularly like this version better than the "sun powered" types (from either Seiko or Citizen) since as long as there is movement you have power. One thing that makes this movement, like all electronic/quartz movements, a "problem" is the coils that can be easily damaged. I wonder why then don't encase them or protect them better...one slip of the screwdriver or tweezers and bye, bye coil!....or buy, buy coil :)

 

Thank you and I'm glad this walkthrough has been found useful!

 

Cheers,

 

Bob

[jdrichard]

Hi all,

I figure these movements were kind of popular and expensive (they are still available). So, since I just saved US$104, the price of them this side of the pond (take or leave a few dollars) I wanted to share my experiences.

First off, the service data:

233_Seiko5M42A,5M43A.pdf

Now for the disassembly:

My order here is a little odd. The movement was in bad shape being an ebay non working watch, just for the exercise at hand. Therefore, sometimes in order not to damage a part, i.e. circuit or coil mainly, other parts are being taken out of the way first to facilitate the disassembly. In some pictures, there is another similar movement which also was used to eventually put together a working one between the 2.

So, here is the 5M42, notice that the 5M43 only adds the day disc, a selector gear we'll mention later and a disc holding clip. Everything else is the same. The new capacitor kit that replaced the bugged original one is: 30235MZ which is also good for the following movements:5M62 and 5M63.

IMG_0194.JPG IMG_0195.JPG

There is no capacitor present in this movement...

IMG_0196.JPG

Notice that this movement can be disassembled each side without interfering with the other side. This means that we can remove all the parts from one side and then turn it and remove all the parts from the other side. Your choice which side you want to start first. I prefer to remove the rotor and keep going on that side (bottom) to ensure there is no damage to the rotor screw and bearings. As an added advantage, I'm also minding the coils and circuit.

IMG_0197.JPG

I would have removed the capacitor clamp, insulator and capacitor unit. This is only possible after the previous step and before the one being illustrated below.

Removing the circuit block cover:

IMG_0198.JPG

I also removed the oscillator weight (rotor) bridge first since the circuit seemed kind of stuck and wanted more visual/elbow room to tackle it:

IMG_0199.JPG

A closer view of this bridge, notice the intermediate wheel for generating rotor:

IMG_0200.JPG IMG_0201.JPG

Now we have a full view of the electronics, in very delicate estate I may add. Luckily the circuit block is OK ( I used the one from the other movement which was in better shape ):

IMG_0202.JPG IMG_0203.JPG

Then, goes the short coil...and the long coil, the generating rotor and generating stator:

IMG_0204.JPG IMG_0206.JPG

IMG_0207.JPG IMG_0208.JPG

We remove the only screw holding the train wheel bridge and look under the "hood":

IMG_0209.JPG IMG_0210.JPG

Here is the underside of the train bridge. You are seeing the setting wheel still stuck to the bridge:

IMG_0211.JPG

In the following pictures we remove the fifth wheel and pinion, fourth wheel and pinion, third wheel and pinion, step rotor, minute wheel, center wheel and pinion...

IMG_0212.JPG IMG_0213.JPG

http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0214.JPG http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0215.JPG

http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0216.JPG http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0217.JPG

http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0218.JPG http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0219.JPG

Then we proceed to the keyless work et al. Removing the train wheel setting lever, switch lever (careful is under tension), setting lever, capacitor connection and yoke:

http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0220.JPG http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0221.JPG

http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0222.JPG http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0223.JPG

http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0224.JPG

We discover underneath the clutch wheel and remove it. Also the rotor stator is removed:

http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0225.JPG http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0226.JPG

http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0227.JPG

At this point we turn over the movement...or what is left of it:

http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0228.JPG

As you see this one is the 5M42 version without the day disc feature. Normally for the 5M43 we pry, carefully with a small screwdriver, the snap for day star for dial disk, the day star with dial disc and the intermediate wheel for day correction. All those parts are similar in shape and location as to the 7S26 mechanical movement so there is no need to illustrate it at this point...if we had gotten it. Note that this movement uses a dial washer.

So we skip the day star and start removing the date dial guard and date dial:

http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0229.JPG

Underneath is the familiar date jumper reminiscent of the Seiko mechanical movements, date driving wheel, intermediate wheel for calendar correction, date correction setting wheel, and hour wheel. I'm not sure about the plate present in this movement, it might have been one of those franken things, but this plate doesn't have the non-removable antimagnetic shield plate. I used the donor movement main plate since it had it.

http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0230.JPG

Here is a picture of the movement using the antimagnetic plate:

http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0239.JPG

So removing each mentioned part:

http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0231.JPG http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0232.JPG

http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0233.JPG http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0234.JPG

And voila! The bare plate:

http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0235.JPG

Now we only need to remove the holding ring for dial and dunk everything in the cleaner...NOT everything! The generating rotors, both coils and circuit block DON'T go in the cleaner! Nor would go the capacitor if we had one in this case. Everything else is fair game. One note of caution, while assembling use plenty of rodico for each part since magnetism is an issue and can attract undesirable particles into the movement. Always check and recheck!

http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif IMG_0238.JPG

From this point on and after cleaning the parts. Assembly is simply a reverse order. Follow the technical data for lubrication...I simply used moebius quartz oil and simplified everything...and maybe a little Seiko S6 here and there, mainly keyless works.

One important data for those who don't have a multimeter and want to check the coils. You are measuring 2 different ranges of resistance/impedance, if your meter is not autoranging, make sure to change the range accordingly.

Here is the final product in its case and with temporary hands...until I get something I really like and can refinish the case.

http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif 20150405_224417.jpg http://www.watchrepairtalk.com/public/style_images/master/attachicon.gif 20150405_224439.jpg

I also forgot to say that this movement uses hands: 65/110/20...so far difficult to find in sport, luminic types...or so it seems from trawling the net!

Hope all this helps! Enjoy!

Cheers,

Bob

PS. Any insight, corrections, suggestions, etc is most appreciated!

great job. Amazing how standard the Seiko parts are across types

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