need some help - seiko skx173

[burned]

hello to all... new here.. have some questions - need the experts...

 

so.. i can't seem to find the correct headline, forum, whatever it's called here...

need some help, input, direction --

i just got back a slightly damaged seiko skx173.. all original,, from 2017 yr.. it was 'jammed'.. the person 'claimed' they dropped it ???.. opened it up - found the 3 slotted screw/nut to the secondary reduction wheel and that wheel - off - rolling around free..the screw/nut looks as if there is no threaded shaft to screw into the bridge.. the wheel looks like the very edges of some teeth are slightly 'blunted' vs sharp point..i cannot see the broken shaft in the 'riser'?? but it is clear for approx 1/16" from the top -in.. 

all the pics online - none depict how long that shaft is and if that 'riser' on the bridge plate is supposed to be open thru ..

i'd prefer to simply obtain a newer bridge plate assembly with the first reduction wheel, pawl, secondary reduction wheel and poss main ratchet wheel? attached and in like new condition - so i could easily swap them out as a assembly/unit.. vs - swapping each piece.. or a new 7s26c movement - plus date day wheels, dial, hands ..

i should mention - after making sure nothing else was 'loose' or 'floating around' - i wound it by screwdriver - and its been working fine for days.. runs a bit fast - 8+ min per day - but pretty sure that's a simple adjustment i'll address after swapping out the 'auto winding' parts section..

so - help... anyone have this assembly.. or direct me to where i could get a newer clean one.. 

otherwise my options (in order) - a new 7s26c and do the swap - to keep it all original (value wise).. or nh35 and more parts and it runs but lost it's OEM value..

open for your input.. excuse me if i keep getting in the wrong 'area'

thanks

jp

 

 

Quote

[gbyleveldt]

That autoworks second reduction wheel and screw (which is reverse threaded) is a wear point on those 7S26 movements. Your easiest option would be to just buy a donor movement and replace those parts. You not going to easily find new parts as those have been discontinued, but you can easily get donor movements used. You can try SpeedTimerKollection for any bits you may need. I use them all the time if you in a hurry. That being said, Seiko made millions of these movements, it won’t be hard to find a donor watch for parts.

[burned]

thanks for the response..

i know i am getting some of these names wrong.. ha.. i'm sort of new to this - but it's like a draw pulling me in... usually i am good with most things - i may have to put this under a microscope to view that 'shaft' - i can't tell if the threads are ok or if there is any blockage halfway down or if that's normal..

never saw a new threaded screw/nut so i don't know how it should look before it fails.. 

i get what you say - and i do believe i've seen the individual parts - yet all added up - i could almost buy an entire new 7s26c.. i was trying to take the easier route..

as for a 'donor' - so far research is confusing as to what models used the 7s26c - as the a and b are not compatible as far i i can tell.. there again as you say - it's their weak or weakest point translating to buy used could be i minute away from what i already have..

i'm hesitantly game for either swapping the bridge (not that super tiny clip for the 1st wheel) and screws and spring sequence..or day wheel, dial, and hands - tiny hands.. i'll be needing a hubble to see ..

i'll give that place a try.. as for a donor - unless i'm lost - i think their prices would be about close to the same as a new movement...

again - appreciate the guidance.. and can always use far more input than most would absorb... i totally am soaking this all in.. and soon -  i can see where this is leading - building a monster or totally sleeking out a sub mod from dead scratch new parts.. i enjoy the challenge..

so .. guide away obi wan...

jp

[gbyleveldt]

Provided the thread for the 2nd reduction wheel post on the top bridge isn’t damaged, you can use a wheel and screw from 7s26a/b/c. The top bridge is slightly different between a/b/c if memory serves. With that broken screw, I’d imagine the rest of it would still be in the post. Like I said, it’s reverse thread so easy to snap off if someone inexperienced has been in there before you. The broken off piece of the screw should be easy to remove and replace.

[watchweasol]

Hi the following is a seiko bulletin which describes the function of the "magic Lever " winding system

https://r.search.yahoo.com/_ylt=AwrJKiD05pli9wcAPAB3Bwx.;_ylu=Y29sbwMEcG9zAzgEdnRpZAMEc2VjA3Ny/RV=2/RE=1654282101/RO=10/RU=https%3a%2f%2fseikoforum.com%2fthreads%2fthe-cornerstone-of-seiko-automatic-winding-technology-the-bi-directional-magic-lever-system.656%2f/RK=2/RS=ihwMttHbC3El1rUrwDyoznj.RQY-

7S26 parts /service sheet attached should you require the part numbers.

Seiko 7S26A, 7S36A.pdf

[burned]

thanks to all so far who offered help...

i've searched extensively - and i still have limited info..

- does the 'tube' that the 2nd wheel rotates on and that screw/nut (lh 3 lines) goes into - is it hollow completely thru to the other side of the bridge plate..

-  based on pics of a 'new screw/nut' it appears to have a length of approx 3 times the thickness of the wide top cap - which would be slightly less than 1/16" based on my 'optical guessing'..

- a smart man offered that versions 'a' 'b' 'c' of 7s26 bridge plates may be slightly diff in layout or shape = meaning i must source only a 'c' version to do a swap or the bridge plate... or even that screw/nut from an earlier version is the same size, dia. thread count.. same goes for 2nd wheel or any other part

- being the last version of this mvmt - a dead donor would be more diff to locate 'cheaper' than the cost of a new mvmt.. and being dead - doesn't mean that when i get it - it doesn't have the very same issue

- if said 'tube' is hollow - mine i think is not.. so not sure i can 'remove' the broken threaded part - and will i damage the existing threads - if they are not already.. i believe that 'tube' is pressed in - but now were talking 'micro-surgery'.. 

- i get that this 'learning process' will cost me to some extent - but - i don't want to pursue stupid paths - like buying a watch to pry off the back - to find out it simply unscrews - then i'm back to sqr 1 - because that was an easy shortcut to say - hey dummy - it unscrews.. 

- i can't believe - with this being so common - no one has posted pictures of this top and bottom along with nice blown up  ones of the 'tube', screw/nut, and my limited options .. far more skilled people have walked this path.. 

- so i will be the first i guess .. in the meantime - if there is anyone who can 'fill in the blanks' for me - cool... even better if they have that bridge plate assembly from a donor - meaning 3 screws and unwind the ratchet for me - way cool - i'll buy you a drink or iced coffee.. just looking for that missing section of knowledge ..

thanks again..

jp

[jdm]

7 minutes ago, burned said:

'..- a smart man offered that versions 'a' 'b' 'c' of 7s26 bridge plates may be slightly diff in layout or shape = meaning i must source only a 'c' version to do a swap or the bridge plate...

These parts are all identical across versions. There are plenty of pictures and videos that show and analyze this kob.t dow to the most minute detail. The rotor post is pressed and can be easily be replaced.

[gbyleveldt]

57 minutes ago, burned said:

- does the 'tube' that the 2nd wheel rotates on and that screw/nut (lh 3 lines) goes into - is it hollow completely thru to the other side of the bridge plate.. Yes

-  based on pics of a 'new screw/nut' it appears to have a length of approx 3 times the thickness of the wide top cap - which would be slightly less than 1/16" based on my 'optical guessing'..

- a smart man offered that versions 'a' 'b' 'c' of 7s26 bridge plates may be slightly diff in layout or shape = meaning i must source only a 'c' version to do a swap or the bridge plate... or even that screw/nut from an earlier version is the same size, dia. thread count.. same goes for 2nd wheel or any other part If the thread in your top plate post isn't damaged, you can use 2nd wheel and screw from any 7Sxx movement. Those parts are all the same

- being the last version of this mvmt - a dead donor would be more diff to locate 'cheaper' than the cost of a new mvmt.. and being dead - doesn't mean that when i get it - it doesn't have the very same issue

- if said 'tube' is hollow - mine i think is not.. so not sure i can 'remove' the broken threaded part - and will i damage the existing threads - if they are not already.. i believe that 'tube' is pressed in - but now were talking 'micro-surgery'.. It is hollow, so if yours isn't then part of the screw is still stuck in it (highly likely)

- i get that this 'learning process' will cost me to some extent - but - i don't want to pursue stupid paths - like buying a watch to pry off the back - to find out it simply unscrews - then i'm back to sqr 1 - because that was an easy shortcut to say - hey dummy - it unscrews.. 

- i can't believe - with this being so common - no one has posted pictures of this top and bottom along with nice blown up  ones of the 'tube', screw/nut, and my limited options .. far more skilled people have walked this path.. 

- so i will be the first i guess .. in the meantime - if there is anyone who can 'fill in the blanks' for me - cool... even better if they have that bridge plate assembly from a donor - meaning 3 screws and unwind the ratchet for me - way cool - i'll buy you a drink or iced coffee.. just looking for that missing section of knowledge ..

thanks again..

jp

See above in bold

[watchweasol]

Hi  take a look at the Ranfft site,  Type Ranfft seiko 726S it will bring up a losting of the model plus all of its family members and associated data.     On the 726SC  and A  the screw part numbers are Identical  0012 539,        as mentioned by jdm, however the barrel,trainwheel bride number differs    C being 0112 300 and the A being 0112 400 so there are variations. The 726S   is the follow on model from the 7009A so one would assume it also shares some parts.  For detailed Seiko information have a look at "The Watch Site"  they adre dedicated Japanese watch enthusiasts.  

[burned]

cool... some great info...

so - my update - since it was raining here...

i released the spring pressure on the ratchet wheel & removed it.. loosened the bridge screws slightly - cut a thin strip of wht paper and slid it just enough to view it passing underneath.. so - the tube/furrel/rotor post -(learning all new correct terms) is not blocked - no obstruction - i can see the paper sliding under..

not having a left handed screw - though the ratchet wheel screw is just about the same dia - wrong thread - poss same length - i get a better idea..

taking a small pin - and sliding it into the ratchet post - as a reference - to 'feel' the threads and resistance as a base line - i'd say my 2nd wheel post is approx 40-60% - threads, depth, count, defined and not completely 360 degrees - so it has suffered some damage by the sneaky person who pretended not to know what happened.. 

i get that the post is pressed in - might be easier to just get a bridge plate - then new 2nd wheel to be safe - and screw/nut.. or 2 .. if - if - i find that the existing post is 50% stripped out with the first nut install..

i will say - there's a lot going on under that plate - def need far more magnification, light, and some additional tools prob.. though i'm concerned that swapping out the entire mvmt and reusing the same hands - they may be loose or i could bend one - and more tools.. plus it's the last option - if i mess this mvmt up..

i'll try to source out some parts.. i noted that some 'sources' claim to only sell to pros or hobbiests - i wonder if that incl me..

not sure how you guys can see when looking up back in the real world - give you credit.. 

again - i appreciate all the help.. and maybe some parts and addition input.. i'm determined to learn, fix this.. and then try something bigger - just for me..

thanks..

jp

 

[gbyleveldt]

Heh, if you were in South Africa I would give you the parts. I have lots here.

[jdm]

1 hour ago, burned said:

i'll try to source out some parts.. i noted that some 'sources' claim to only sell to pros or hobbiests - i wonder if that incl me.

For this watch and similar don't bother buying new parts, all you need is one or two cheap broken mov.ts from Ebay and the like. Or fit a new NH36 which is not expensive and will give a new life.

1 hour ago, watchweasol said:

.  On the 726SC  and A  the screw part numbers are Identical  0012 539,        as mentioned by jdm, however the barrel,trainwheel bride number differs    C being 0112 300 and the A being 0112 400 so there are variations.

This kind of compatibility information, including details on what exactly changes, can be found in the document that I maintain:

https://docs.google.com/spreadsheets/d/e/2PACX-1vRN2UULQKTfKmhRStZhDdIOIQrqd6sPB-g6x2SKyQQjOvTBjG_7TQXQhAT4f1WqAX5QAPkIimi-3jqd/pubhtml

 

Edited June 3, 2022 by jdm

[burned]

21 hours ago, gbyleveldt said:

Heh, if you were in South Africa I would give you the parts. I have lots here.

i appreciate the thought... sadly i am thousands of miles away - north east USA..

wonder if that tiny assembly would make it safely in a padded envelope

 

21 hours ago, jdm said:

For this watch and similar don't bother buying new parts, all you need is one or two cheap broken mov.ts from Ebay and the like. Or fit a new NH36 which is not expensive and will give a new life.

This kind of compatibility information, including details on what exactly changes, can be found in the document that I maintain:

https://docs.google.com/spreadsheets/d/e/2PACX-1vRN2UULQKTfKmhRStZhDdIOIQrqd6sPB-g6x2SKyQQjOvTBjG_7TQXQhAT4f1WqAX5QAPkIimi-3jqd/pubhtml

 

i did search thru ebay - can't find anything 7s26c - it's the 'c' because of the bridge plate .. a couple yet their prices were like buying a new mvmt.. not sure where you guys find these 'dead' pieces for 10 bucks.. 

as for the offshore sources - it's the wknd - they must be off..

regarding the nh36 - still concerned - more pieces - like stem, crown, day wheel, dial, hands - or most of these because at some point i prefer to fix this.. and even if not - the all original vs modded has a value or loss of value.. 

[jdm]

3 hours ago, burned said:

I did search thru ebay - can't find anything 7s26c - it's the 'c' because of the bridge plate ..

As mentioned above, the rotor post that you need is easily replaced from a bridge to another.

3 hours ago, burned said:

a couple yet their prices were like buying a new mvmt.. not sure where you guys find these 'dead' pieces for 10 bucks.

Most often form the Philippines. There is also a good seller in Spain.

3 hours ago, burned said:

regarding the nh36 - still concerned - more pieces - like stem, crown, day wheel, dial, hands - or most of these because at some point i prefer to fix this.. and even if not - the all original vs modded has a value or loss of value.. 

The only part that you need when fitting an NH36 to a threaded tube case is a crown/stem combo (again from the PI). All the rest from the original do fit directly. Also, before swearing on the goodness of the original mov.t you should check if it is running well on a timegrapher. Often the balance / escapement has been messed up or is worn out, and that is basically non-fixable by a beginner.

Edited June 4, 2022 by jdm

[burned]

5 hours ago, jdm said:

As mentioned above, the rotor post that you need is easily replaced from a bridge to another.

Most often form the Philippines. There is also a good seller in Spain.

The only part that you need when fitting an NH36 to a threaded tube case is a crown/stem combo (again from the PI). All the rest from the original do fit directly. Also, before swearing on the goodness of the original mov.t you should check if it is running well on a timegrapher. Often the balance / escapement has been messed up or is worn out, and that is basically non-fixable by a beginner.

thanks.. i know - i had read that.. and normally - if it was bigger in real life - it wouldn't be a thought - but that thing is super small.. and i'm def not used to playing with such small parts.. besides - i still need the screw/nut and want a new 2nd wheel.. poss ratchet wheel as well..  so.. also i would prob need tools i don't have currently to place that tube before pressing..

as to the supplier/sources - care to elaborate... please..

and you are correct - i can obtain a new stem & crown usually from the same supplier as a nh36.. and use my black plastic shim.. though i have to swap out the day disk and that tiny c clip, the dial, and the hands.. as i was hoping to salvage this one - and or use whichever was leftover to insert into a new body for a custom one for me - which would mean keeping those above parts on this unit and buying new ones to replace them.. 

and i totally am getting your note to get this officially checked out - i was simply planning on getting it up and running 'normally' before spending on that - esp if i need a new mvmt.. plus i was looking to fix this - a challenge for me - vs letting the pro .. how else will i learn.. another reason as to why i seek real advice.. plus i have adjusted the 'running' to 2 min fast per day now.. and the day n date work correctly.. so... 

i get the balance set up - i've watched enough videos to see just how delicate that is.. as for the escape wheel - thing looks like i barely touches and a mouse breath would misalign it.. so yes - i get it.. and i do not have the tiny tweezers and mag to try that one - unless i was stuck on an island.. 

but - if it's running now.. and is consistent.. and appears 'normal' - short of not being able to wind itself.. maybe i got half lucky..??? 

definitely learned a lot .. 

jp