Movement Swap: Seiko 7S26 to 4R36
I have an older model Seiko 5 which, unfortunately still have 7S26 movement. Ever since I acquired the watch, I have bought 2 Seikos with 4R series movement and unsurprisingly, I prefer.
Is it worth it, possible and advised to swap my older Seiko5 to a 4R movement? Are the small dimensional difference would be a problem?
10 comments
Sort by
Fadhil
I have a corporate career and run an IT Consulting Firm to feed my watch addiction.
Indonesia
Member since
Last active: 11 hrs ago
6.50” / 16.51 cm
I swap all my 7S26 movements with NH movements. No issues, though I've seen some forums say to keep the black spacer from the 7S and replace the gray spacer on the NH. I also keep the 7S rotor.
I swap all my 7S26 movements with NH movements. No issues, though I've seen some forums say to keep the black spacer from the 7S and replace the gray spacer on the NH. I also keep the 7S rotor.
Do you have any issue with the sizing and/or the stem length?
Do you have any issue with the sizing and/or the stem length?
I've messed up cutting the stems too short before so I have extras on hand. Now I cut them close and file them down, works much better.
I've messed up cutting the stems too short before so I have extras on hand. Now I cut them close and file them down, works much better.
That’s one of my concern on doing this mod, I’ll make sure to order extra stems. What tool works best for cutting the stem?
That’s one of my concern on doing this mod, I’ll make sure to order extra stems. What tool works best for cutting the stem?
You'll want a pin vise to hold the stem, end cutting pliers to make the cut, a diamond file to file the edge, and non-permanent Loctite. You'll want to file the stem at an angle so it's easier to feed into the crown. There are some YouTube videos that explain it well.
This is a huge help, thanks. Buying these things as writing this
This is a huge help, thanks. Buying these things as writing this
You'll need to remove the hands and dial from the movement. Do you have hand removers and pressers?
You'll need to remove the hands and dial from the movement. Do you have hand removers and pressers?
No, I don't, adding hand removers to my cart. Is presser necessary though? Anyway, which model were you working the movement swap on?
No, I don't, adding hand removers to my cart. Is presser necessary though? Anyway, which model were you working the movement swap on?
You'll need hands pushers or a hand press to get the handset back on. I recommend getting some rodico. You can put the rodico on a toothpick to hold the hands in place while you set them.
I've done this with an SKX and a few old Seiko 5's.
Good post. Thanks to @madminuteman for the tips! Don’t think I’ll do this anytime soon, but good to hear from someone with experience. Perhaps a project someday if I find a nice 7S26 example cheap somewhere 🤝