Supercharge your SKX007 with a NH35/36

Edited : 28/6/2018 (added my own custom made “S” crown for SKX007 diver mod)
Edited : 12/12/2017 (add Mr Jake of Dagaz video on dismantle the SKX)

After doing the “Triple charge your Seiko SKX007 with Dragon Shroud, Jumbo crown and a NH36 !” article.
( ) .

I have been receiving many request to do a tutorial for  updating the SKX007 <or SKX009> to the later NE15 (6R15) or NH35 (4R35) movement while highlighting the necessary parts swap to make it work !

Since i do not have any similar project currently. I will be writing this tutorial basing on mine existing pictorial and Nicholas Hacko’s excellent 7S26 servicing pictorial. (Credit goes to Nicholas Hacko).

For this “Supercharge your SKX007 with a NH35/36” tutorial, i am assuming that you have the tools and know how to remove the :

a) back case

b) stem

c) hands

c) dial

d) remove movement from the watch case


Lets begin with the parts swap.

NEW pre-cut NH35 Stem
You will need a new NH35 stem (the 7S26 stem will not work with NH35 movement).
I have the pre-cut, plug and play NH35 stem here ( )
*the stem extender is provided free-of-charge if you are using the pre-cut stem for other application.

**below pix shows the stem differences.

NEW aftermarket crown
Original Seiko SKX007 crown and stem are not detachable. So a aftermarket replacement from the ebay will needs to be sourced.
*see the difference below pix.

OR Seiko’s SARB059 cr0wn
If you are a purist and really “MUST and INSIST” to use an original Seiko crown. Or using an aftermarket crown wouldn’t let you sleep in peace.
You can try to find the SARB059 crown [Seiko Part Number 1E70D1SNS0]. This crown has a detachable stem and is a direct swap on the SKX007 Case. For Bonus ! It has a “S” marking at the crown too !

Many have asked me to supply them with an aftermarket crown and a suitable pre-cut length NH35/NH36 stem as a package.
OK guys, after many consideration and investment. I have decided to go ahead and custom made my own “S” crown for the SKX007 Supercharge upgrade.

They are custom made as close to the SARB059 crown as possible but with some improvement.

Lets have a look at the new “S” crown improvement :

The “S” crown

The pre-cut stem will fit nicely onto the “S” crown to provide a plug and play application !

They are made with “Double gasket” for added water resist application !

Additional crown “Bottom gasket” for even more water resist assurance !

So there you have it guy ! The “S” crown option.

Its offer “S” crown alone or a fix with the pre-cut stem.

You can read more about the “S” crown here :


OK, once you have the above sorted out. Next will be the plastic movement spacer.

NH35 movement comes with the gray plastic movement spacer. See pix below.

Seiko makes 2 type of plastic movement spacer the 2mm (Gray) and the 3mm (Black) spacer thickness.

Although it has been reported that the NH35 Gray spacer work well in the SKX007 watch case and swapping the thicker black spacer is not necessary. A little investigation reveal that the casing diameter is slightly bigger for the NH35 (which may explained the tighter fit and get away with it).

Anyway, we will do a proper job by also swapping the Seiko black plastic movement spacer into the NH35.

Most of the NH35 available in the market currently are 3pm DATE position. It fit well into the SKX dial but needs to transfer DAY wheels from the 7S26 to the NH35. (For NH36 with DAY/DATE, they are also at 3pm position. The DAY location will be misaligned when installed on the SKX dial (see below pix). Similar works will needs to be performed too. So no difference buying the NH35 or NH36 movement !).

Below Nicholas Hacko’s excellent DAY/DATE removal guide below [so i don’t have re-do this part] :

Remove the snap clip

Remove the day wheel

Remove the intermediate day correction wheel

Remove the 4 screws

Remove the plate

Remove the DAY/DATE setting wheel

IF you are just swapping the DAY wheel. Do the same for the other movement and install with reverse procedure.

That will complete your necessary swap required for “Supercharging your SKX007 with a NH35” !

Note : i am not taking calendar wheel colours into account at this stage.

IF calendar wheel colour is a concern, please proceed with additional steps below on swapping out the DATE wheels too !


Remove jumper plate

Remove date wheel

Do the same for the other movement and install with reverse procedure.


Some reader has asked me about adding a tutorial on dismantling the Seiko SKX.

Mr Jake of Dagaz has previously done an excellent video which is about 6.5 minutes on the works. Do enjoy his video below.

(Credit goes to Mr Jake of Dagaz)



OK, there you have it. Hope you guys enjoy the “Supercharge your SKX007 with a NH35” !




  1. Richard Erickson · · Reply

    I am new to this whole swap movement thing but am willing to try it because my skx173 is annoying fast then slow, theme stops and not very accurate. Hopefully you can help me with a few things. I have a brand new Nh35 and a brand new seiko sarb 059 crown with stem attached. So, what I understand is all I have to do is: use black spacer with nh35 movement.
    Use the Sarb 059 crown, minus the stem and put it back together, no problem! Right???
    Hopefully I can get the stem off by taking the gasket off and putting it in hot water for a while before taking it apart! Does all this sound correct???

    1. Hi,

      Your understanding is correct !

  2. Thanks for sharing your knowledge! It was very helpful. We hope you don’t mind us sharing this with our followers.

  3. Reblogged this on Strapcode and commented:
    How to take your Seiko SKX007 movement out of the case

  4. […] Source: Supercharge your SKX007 with a NH35 […]

  5. Sure strapcode ! Go ahead and share it !
    Glad you enjoy it.

  6. Norbert ERdei · · Reply

    Nice instruction!

    I bought a 7S36 (NH36A) movement for my SKX007. I have all parts for modding, except the crown. I have a 7S26 crown and stem, which are not detachable. What to buy? Will this SARB059 crown work with my movement? Thank You for reply!

    1. Yes, the SARB059 crown will work. You will also need NH36 stem.

      *meantime 7S36 is not a NH36. 7S36 is similar to 7S26 not hacking or manual winding function

  7. Norbert Erdei · · Reply

    A week ago I bought here and (received- thanks for them) stem for my NH36A. In this case I’ll order on ebay that beutiful SARB059 crown. It would be a real crown on my modded SKX007.
    Thank You for the answer!

    But..Will not my movement be a hand-winding and hacking stucture? I wanted to upgrade from 7S26..

    1. You will need to swap either aNH35,NH36, 4r35,4r36, 6r15.
      All uses the same stem

  8. Norbert Erdei · · Reply

    My (probably) last question: where can I buy one of these movements? On ebay I just found NH36A – which You say- not hand winding, hacking structure.
    I found this, but I think this one is also a NH36A, not an NH36.

    Thank You all Your help!

  9. Just send u a email

  10. S. Antonov · · Reply

    Where can I buy Seiko 4R36 movement, Seiko SRPB11K1 Dial (part number 4R3604Z4XL23) and full set hands?

    1. You can buy a NH35/NH36 (similar to 4R36) here :

      For the Turtle Reissue Seiko SRPB11K1 dial and hands, suggest you scout them at various sales forum. Some time you might get lucky.

  11. Manny Bernard · · Reply

    Any watch repairer available to do this job? I have all the parts.

    1. Hi Bernard, It will helps if you state your place.

  12. Manny Bernard · · Reply

    Puerto Rico, USA. Can ship to any place.

  13. I am sure there will be Seiko Fans in Puerto Rico which can help. Have you try in USA ? There is a few modder there whom can take the job.

  14. Manny Bernard · · Reply

    That’s what I’m looking for. I tried here with no results. Kindly request someone I can sent the mod no matter where it is.

  15. I am not sure about Puerto Rico, but here is a list of modder nearest to you in USA.

    USA Epping, New Hampshire Wayne Blaney
    USA Florida, USA Ryan Bond
    USA Los Angeles, CA Ray Dollete
    USA Michigan Jeff Elgas
    USA Nashville TN Alan Markle
    USA New Jersey Dave Sutton Facebook or
    USA Overland Park, Kansas KC Watch 913-381-2675
    USA Philadelphia Aaron Grando
    USA VA Crystal “CG”

  16. Great article and thanks for your skill and advice. My question: I am planning to modify a Seiko 5 for my father by changing the current dial for an instrument type with big hands that are easier for him to see. My Dad doesn’t want the day/date so I will source a plain face, no problem. Should I just change the dial and cover up the day/date or could I remove the day and date dials and wheels and leave them out of the watch entirely?

    1. Hi Neil, there is no need to remove the day or date wheel. The movement and dial (non day/date) will work just nice.
      Enjoy the mod. Write back (or email) should you need more assistance.

      1. That’s clear, many thanks indeed.

  17. S. Antonov · · Reply

    I plan to supercharge my SKX007 with 6R15. I already have SARB059 crown on the way, but have serious worries about “date-only dial” part.

    Did I need to get dial like Sumo (6R15 basedwatches with 4:00 crown) or anyone will fit? Local dealer of Seiko parts can find for me original Seiko SRPB53 Samurai dial, chapter ring and full set hands. This is 4R35 based watch with 3:00 crown, did this dial and chapter ring i`ll fit 007 case?

    I was not able to like custom dial, probably will use original Seiko dial of another model, the question is which one will fit?

  18. Firstly, the SARB Crown is a good start.
    Secondly the 6R15 will work, but its a date only as you are aware.

    Just the Sumo dial and the 6R15 will work on the SKX ! You dont need any other parts.

    Alternatively, you can also choose to swap parts (day wheel, day corrector set gears) from the SKX’s 7S26 to the 6R15 and make it a day/date !
    In this way you can use back the SKX dial.

  19. S. Antonov · · Reply

    This mean SRPB53 Samurai dial will not fit because his 3:00h crown?

  20. For the Samurai dial (3pm crown) to fit into the SKX case (4pm crown… 3.45pm crown actually).
    The dial feet will needs to be removed and secure with dial dot. So technically its still possible with some mod. (This is not accepted by purist).

    For simplicity, using any Seiko’s dial which is at 4pm (and using either 7Sxx / 4Rxx / 6Rxx movt) will work.

  21. Hello, will the NH36 stem work on a swap to a SKX013 case (midsize diver)? Or can I trim it a bit?

    1. Hi Dan

      The precut NH35 stem should work on the SKX013 !

  22. Hi Chuen,

    Your site is full of great tips! I want to upgrade my SKX007 movement to an NH35 movement. Do you sell this as a kit? I don’t want to buy all of the parts from many different sellers.

    Or do you sell NH35 movements that are ready to go into an SKX007 with all of the modifications made?

    Kind Regards,


    1. Hi Steve

      I have the NH36 movement and pre-cut NH35/36 stem.
      For the crown buy the ebay SKX aftermarket ones.
      And you are set to go.
      Had send you similar email reply.

  23. Ive been reading elsewhere that the nh36 movement is too tall to fit in the SKX007. The second hand will rub against the glass. Is this true?

    1. For the SKX application, it does not touch the crystal.

  24. There is no need to attempt a stem swap to the SARB059 crown, it already has the required stem fitted (6R15 and 4R35/6 are the same movement apart from finish and hairspring and mainspring material). In fact, the SARB crown stem is a one piece unit, and can not be separated- to the best of my knowledge.

    1. Correctly said !

  25. Great wealth of info. One slightly different question.

    I have a midsized skx013 that I want to mod with a 4r36 movement. I have the movement from a donor watch, however I’ve not sure what stem and crown to use.

    I’ve read that a SARB059 crown will not work because it’s too big but I’m not sure if this is true.

    Also, don’t know if the 013 crown and stem is not detachable like the stock 007 stem and crown.

    I know the mod can be done. I’ve seen them online here and there but when I ask those people about them they don’t respond.

    Thanks for any input.

    1. I believed the SKX013 crown/stem are also non-detachable ; like the SKX007.
      Similarly, you can get an aftermarket crown (its shorter compared to the 007) from the bay. This will enable you to use the 4R/NH stem.

  26. will the crown and stem of the seiko turtle work on the case of the skx? I’m unable to find the sarb059 crown.

    1. Nope. It will not work.
      Stem length is also different.

      Currently, I will still suggest the eBay after market SKX crown or Dragon shroud Jumbo crown.

      *another option is to try to New 4R Samurai crown.

      1. Puthearith Chea · ·

        Many thanks. I will look around.

  27. Is it confirm that the Samurai Crown is a plug and play with either the NH35/36 or 6R15 upgrade? I notice that the Samuria Crown comes with the stem on it already.

    1. Yes, it will fit (just like the SARB059 ones) !
      My order with my supply source is pending since end Jan.
      It takes alot of time. Once they arrive will put them up on the website.
      (Limited qty thou).

  28. IAmHolland · · Reply

    It’s not 100% clear to me. To make the NH36 into 4 o’clock, you need all 3 wheels swapped…the Day Wheel, the intermediate day correction wheel, and the day-date correction wheel swapped? Or is it just 2 wheels (Day Wheel and the intermediate day correction wheel)?

    1. Hi, Just only the intermediate day correction wheel and the DAY wheel disc is needed from the 7S26 into the NH35.
      For NH36, only need to swap the DAY wheel disc (the intermediate day correction wheel is already there).

  29. Is the 6R15 really worth the extra $$$. Other than 50 hrs reserve what is major advantage to the NH35/36?

    1. The 6R has a nicer engraving.
      In my opinion, these are the 2 main advantage. So is it worth it ?

    2. IAmHolland · · Reply

      6R15 has better accuracy. -15 -> +20 vs -20 -> +40. It’s like comparing a 2824-2 to a 2892-A2. It probably has more refined and better spec’d parts in it. It will keep time, in various positions, closer. I’d have to look at the technical manual to see if there are build differences, other than parts. If that’s not something you care about, then it’s not worth it.

      1. As the previous contributor has stated – better rate stability all round. The only two differences between the two are – 1, the mainspring being SPRON510 on the 6R15 vs SPRON100 – the better spring not only increases duration, but also gives a more even torque output at lower states of wind – ( lower torque = watch runs fast) 2, the balance and hairspring are different , the hairspring being SPRON610 – which is a much superior material and equivalent to the materials used in many high end Swiss movements. It’s stability is also better and less affected by temperature. Both the SPRON 510 AND 610 springs are virtually non-magnetic and shouldn’t be as affected by such. The 6R15 should also be adjusted better from the factory and display less isochronism. Having said that, my NH36 runs very nicely and loses approx 30 seconds every 10 days when worn 24/7.

  30. So far I can only source a 6R15 thru eBay and it almost a price of an SKX007K1 already. Can anyone give some leads on where to get this movement at a better price? Thanks in advance.

    1. IAmHolland · · Reply

      Search for the NE15.

    2. IAmHolland · · Reply

      It is not cheap, easily 3x the cost of the 4R35/4R36.

  31. Esteban · · Reply

    Hello Chuen,
    I have a modding quest that’s been driving me nuts!
    I would like to put my new NH36 in my SKX031, I am having trouble because I have no idea what crown to get that will fit the stem the NH36 came with. Do you have any ideas or suggestions? I was thinking about getting the crown protectors removed from the 031 and buying a sarb059 or sxk007 crown and going about it that way, but I don’t know if it’ll fit through the 031 tube?
    Best regards,

    1. The original crown/stem for the SKX031/33 are non-detachable (just like the SKX007). Therefore an aftermarket one needs to be source (ebay…..just like the SKX007 also). You can use the pre-cut stem with a little sanding to the length to accomodate (test fit first before sanding, as some report it fit while other say its just a tad longer).

      *Dont think the SKX crown will fit.

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