Orange Monster Movement Swap

[Jster]

I have the Seiko Orange Monster, 1st generation, Model SKX781. I bought it new in 2007. It’s the second oldest watch in my collection (the Omega Seamaster 2254.50 is the oldest) and one of my absolute favorites. I love the bold look and the orange dial is amazing.

The main drawback of the watch is the 7S26 movement. You can’t wind it with the crown so you have to shake it to get it going. The movement also doesn’t hack but that is not a big deal to me. I found it annoying to not be able to wind the watch normally and it made the watch feel cheap. Also, the movement is not very accurate. I tried regulating it myself and it is very sensitive to any adjustment. I actually had it serviced a couple of years ago and within a couple of months it was just as inaccurate as before.

All this resulted in me not wearing the watch very much even though I loved the aesthetics of it. I happened to be browsing a couple of websites and stumbled across an article on modding the Monster with an NH36 movement. I knew modding Seiko’s was a big thing but it never occurred to me to put in a completely different movement. I like to work on mechanical watches as a hobby so I thought this would be a fun project to undertake. I can’t believe it took me this long to realize that this a relatively easy and cheap way to drastically improve the watch.

There are several articles and videos available to the internet that explain the process. It’s fairly straightforward for someone who has worked on mechanical watches and has the proper tools, but I wouldn’t recommend it to a first timer. I purchased a NH36 movement off Ebay for $60. This movement has crown winding and hacks. It’s also supposed to be more accurate than the 7S26.

The movement swap requires removing the day wheel from the 7S26 and swapping it into the NH36. This is because the Monster has the crown at 4:00 and the NH36 day wheel is aligned for a crown at 3:00. Also several articles and videos suggested reusing the movement ring from the 7S26 for a better fit, which I did.

Another peculiarity of the Monster with the 7S26 movement is that the crown and stem are one piece and is not interchangeable with the NH36. A couple of the articles I read said that the crown and stem (also one piece) for a Seiko Alpinist SARB059 would fit perfectly. As a warning, I found that it didn’t fit. I bought one on Ebay for $40 and it was just a little too short. I then bought a coin edged crown for $30, that came with a separate stem that fit the NH36. The stem is purposely very long so it can be cut to fit a variety of case sizes. This requires some precise measuring and careful cutting and filing to get the stem to the correct length.

The movement swap turned out great and now I’m in love the Orange Monster all over again. I love being able to wind it with the crown and the hacking feature is a nice bonus. It’s running about 15 seconds a day fast, which is fine with me.



Leftover Parts:
Movement and crown/stem from original 7S26
Day wheel and movement ring from new NH36
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SARB059 crown/stem (on left) just a little shorter than the original
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Love it on a simple black rubber strap (Bonetto Cinturini 270)
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Obligatory wrist shot
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[joli160]

Nice modification, great write up. Time to enjoy it

[1William]

Great watch.

[DJ2020]

That's a nice report. Thank you for sharing. And great job by the way!

[ttomczak]

Awesome, I wish I could do this.