Seiko NH35 - NH35A Part 2 Service - Reassembly

Part 2 of a 2 part video set covering the disassembly and reassembly and oiling of a Seiko NH35A movement, a popular and ubiquitous movement which replaced the 7S26 adding useful features of hacking and hand winding, this movement is used across a very wide range of homage and custom watches and is the equivalent to Seiko's in house calibre 4R35.

[@mikeolly67]

thank you, you saved my sanity. I have an nh35a movement and the stem would no longer push past the first position. I decided to have a go at fixing it myself, im a complete amature and only ever changed dials and hands and crystals, so removing tiny screws and cogs is really beyond my talent, i think the clutch wheel and winding pinion were causing the issue. I was fine taking it apart but then couldnt work out how it all went back together. Thankfully I found this video and managed to get it reassembled, and fixed.

[@spidiq8]

That's great news. Glad it helped.

[@Pentaw1nz0r]

Excellent video. My stem was stuck so i decided to open up my nh35 to remove it. Then i was screwed since i have absolutely 0 knowledge about watches. You saved my nh35, is working again!

[@justice4all72]

Thank you very much for showing this! I really enjoyed it, I have this movement in my daily watch and never knew how intricate it was, watches are truly magnificent pieces.

[@gary2632]

Thank you so much - very helpful after a partial strip down to remove a broken stem. Much appreciated 🙏

[@scdevon]

Great work! I have a TMI version NH35A in a Pagani watch and it's a great runner. +3 secs a day and a reliable auto-winder with daily wear.

[@hamzaalmasharawy9275]

Hello, where is the NH35A TMI machine made?

[@tatarugabriel4328]

I was never aware of the fact that having the watch on the other hand can impact the winding performance. Great vid

[@spidiq8]

Thank you. In reality the difference would be so minimal that you'd be unlikely to notice. The system is very efficient and will wind fully in 4 to 5 hours from empty on regular non energetic wear.

[@aralevonian8391]

Thanks for this EXCELLENT video part 1 and 2, I am a Seiko modder in AUS and got stuck with a snapped stem embedded in the movement, followed your instructions and disassembled and re-assembled after removing said offender and all good, you have me subscribed.

[@spidiq8]

Very glad I could help. I was surprised there weren't other videos on this when I filmed it with it being such a popular movement for the homage market as well as Seikos own.

[@guybuddy]

I honestly didn't know it mattered what way you put the rotor back on, good to know!

[@windward2818]

The Hack is described by Seiko as the Balance Stop Lever with S-6 (Seiko Grease) applied on top of the lever (after installed) at the knee area across from the large pin (dowel).

[@neilmackellaig1337]

The method you use to lubricate the cap jewels is very interesting & I will certainly be giving that a go.

[@spidiq8]

I normally use the 1A auto for these but thought I'd try this out as an alternative and was pretty pleased at how it worked. It's pretty much the same as the old method for pulling old non shock balance jewels where you'd oil and then then poke a fine piece of wire through to carry the oil to the cap jewel and of course it's a much cheaper alternative to folks who can't justify shelling out £70+ on an auto oiler

[@Inkreptile]

@@spidiq8 I've seen some bergeon A1 oiler clones on aliexpress heard lots of good thinks about them... Maybe I should try one

[@SQueme]

Thanks for sharing!! two extra tricks i have learned that are quite helpful for this movement : 10:50 the jumper spring could be set After the next plate (11:01) if this last one is Not Screwed Tightly, but Just placed and Loosely Screwed first ... much easier 10:15 note that the hole covered by this plastic star ... can also be VERY HELPFUL for refitting the motion work, without removing anything on the other side : the clutch can be pushed (toward the center of the movement, do not break it by just pushing on it from the top !!) with a screwdriver "left here" floating, so you can put the different elements supported by the "winding stem" without worrying of the placement of that clutch ... hope they will help, i have several videos of watches repaired but ... did not took time to record theses tricks

[@spidiq8]

Thank you. Tips and suggestions are always appreciated.

[@danlscan]

We had one watchmaker (now zero) in my area. He was good but would not service anything other than Swedish movements. I don't yet possess the skill to disassemble and clean my NH35, so I replaced it. I figure I'll practice with the old movement and see if I can get it running. Thanks for the video! Good and cheap is what I like but I sure would like to own a hand crafted watch one day.

[@cristobalosuna3106]

Thank you for both videos! It is nice to see that the barrel arbor is jeweled, also, when I started collecting Seikos nobody would take them for service in Geneva, they scoffed at the movement having plastic parts!

[@spidiq8]

You're welcome. That's ludicrous though. Seiko have used plastic parts in the calendar works of their mechanical watches since the mid seventies at least.

[@Dr.Gunsmith]

Absolutely brilliant, just what the doctor ordered 🙏

[@davebudd1429]

So interesting, thank you for making this.

[@soaremicheledavid6020]

Watched this video, because inwanted to change the datewheel and the 2 small wheels just jumpes and did not know the order, thanks!

[@tzeimet]

Thanks for the video, you're a lifesaver!

[@Dionysor]

thank you kindly for this journey. i didn't expect anyone to service a movement as cheap as this but it's great hardware for value nevertheless right? it's great knowing what lives in my pagani 1651 and when the time is right i might tackle on servicing this beauty myself. cheers

[@spidiq8]

Glad you enjoyed it and yes, for the cost of a replacement it's probably the best value mechanical movement to date. It's incredible that they can make them so cheaply and do have a go, servicing is as straightforward as any Seiko 3 hand model, cheap movements and watches on eBay are great sources of practice movements, also come on over to watch repair lessons on Facebook if you're not a member.

[@davelowey3074]

Hi q i upgrade from D5 to 9104 (hp1300) because it's a fully synthetic oil for high pressure applications works lovely, i still have D5 but don't use it as much, i started using what alot of pros are 9010 hp1300 and Molycote DX, thanks to our friend in the Netherlands, but nothing wrong with it don't get me wrong it's a great oil, another excellent video mate. Cherrs q8 oils are so expensive

[@spidiq8]

Thanks. Last replacement I was pondering HP1300 but I tend to find D5 doesn't creep much and I'm so used to it. I will have to try some when I need to renew again. I'm always wary of changing things that work well for me.

[@thegrumpymuso5418]

Excellent tutorial and video. Busy modding a watch with a NH35A and the keyless works wan't functioning properly. Your video really helped but still can't understand why Seiko put the keyless on the other side of the movement. Still, all back together and working again.

[@spidiq8]

The 7S26 it's based on did the same. It's baffling.

[@thegrumpymuso5418]

@@spidiq8 Time to watch another of your videos as I’ve got an AS2066 sitting here that needs stripping down and a service.

[@spidiq8]

@@thegrumpymuso5418 Have fun with it. Take your time and plenty of pictures of the calendar mechanism

[@matthewbishop9342]

Please can you tell me why you rotated the movement holder.180 degrees when you were fitting the balance wheel?

[@yvesrinterknecht1451]

i'm having issue reinstalling my escape wheel, is it meant to be fixed in place within the stem of it in a hole? Mine is in place but still is unbalanced and moves around

[@richardneel6953]

I realize this is an old video, but wondering if you still see the comments here. At 11:08 in the video, there is a cutout for what looks like wheel that the arrow shaped spring is "pointing at". I got a new movement today and drove myself crazy looking for, what I assumed, to be a missing part. There's nothing there in your movement either. Any idea what that area is for?

[@carlodelavera9735]

Question: if i was to remove the plastic wheels, the plastic star, the plate and the calendar wheel itself would it just become an NH38? would it cause any issues? I'm thinking about doing so to a watch that has a ghost date position. Date is obviously not needed.

[@michelcarlos01]

Thank you for this video! I watched so many times. I'm trying to learn how to service this movement for hobby. I removed one of the cap jewelled spring at one of the cap jewels (at the train wheel bridge) and was never able to put back. Would you know if there is any tool I can use to install this spring? Thank you!

[@tiberiuvincze8288]

It's a special tool for that , saw in a video , or with wood special form after it

[@tiberiuvincze8288]

or can see a vide by My Retro watches has an video just fot this

[@spidiq8]

There are specific Kif tools or you can make one simply, see here. kzbin.info/www/bejne/pICqeax3hcieeKc

[@michelcarlos01]

@@spidiq8 thank you!

[@joaniebarc6763]

does the back have to be removed to replace the crown assy?

[@spidiq8]

Yes you'll need to remove the stem and the crown and stem screw together.

[@giacomodelbianco]

I didn't see how you lubricated the wheels. Which kind of eyedropper did you use for oiling for example the central jewel?

[@spidiq8]

I don't show the oiling fully in all the videos but for almost everything I use the Bergeon black oiler which is the smallest. For some applications you need to apply twice, I find it better for myself to do this and guage as you go as it's easier to apply more if needed but not to remove if you add too much in one application.

[@marclafferty6416]

I have one of these movements that didn’t work. I bought 3 for mods and one was a non worker I got my money back for it. I’d love to get it working but I don’t have the skill or patience to sort it 🤣. Both videos were great and very interesting. Maybe one day I’ll man up and have a go

[@spidiq8]

If it cost you nothing you've nothing to lose and they're a good movement to practice on.

[@marclafferty6416]

@@spidiq8 one day maybe 🤣

[@spidiq8]

@@marclafferty6416 Go for it. A set of screwdrivers and a pair of tweezers and see how it goes. A new NH35 is about £30 so it's the best deal for practice movements you'll find.

[@hamradioshack9066]

Great video thank you

[@rbaynz]

Thank you very much for the video. I have a cheap watch with NH35A TMI branded on the rotor. I noticed the second intermediate reduction wheel, which the magic levers pushes and pulls, is rather crude. the teeth are uneven and there are scars on the edges. Could this movement be a counterfeit? your opinion is greatly appreciated. Rui

[@spidiq8]

Hi, yes it is possible that it's a copy, however the NH35 is so cheap it's rare to see them and they're normally very obvious and poor in finish. It's possible that you got one which has a detective part, these are mass manufactured movements and errors can creep in. If it's a fairly new watch you should be able to have it exchanged.

[@LCMNUNES1962]

MUITO BOM TRABALHO PROFISSIONAL 👍👍👍 🇧🇷

[@spidiq8]

Thank you, very kind of you.

[@mariopinder242]

How good are the Seiko movements vs Swiss movements. Are the Swiss movements way and above the Japanese movements ? In my personal experience - my Seiko movements seems to not give any trouble. I have had my SKX for years and it’s still running pretty good. But I think it’s time for a service.

[@spidiq8]

They are OK, and like the swiss movements vary in quality. There are plenty of 70's poor quality Swiss movements and there are a mixed bag of excellent and poor japanese movements. The Seiko mainstream movements and current NH ones are very good for mass produced machine assembled movements.

[@dontflyspirit6535]

Does NH35 use plastic pallet fork?

[@spidiq8]

No, it uses a conventional metal fork with ruby jewels. The only movements using the plastic ones are certain base ETA movements typically utilised by Swatch and Tissot. Don't be put off by them, they're a very tough self lubricating nylon material and work excellently.

[@1988banker]

If the levers on the nh35 were moved out of position, would you reset those before reinstalling the balance wheel?

[@spidiq8]

There is no fixed position for them they need to be set using a timegrapher (timing machine) with the balance in place.

[@1988banker]

@@spidiq8 Thanks, my question is out of intrigue. I was just wondering if after you serviced the watch, would you need to regulate it on a timegrapher as well? Provided that it needed it? I'm sure after service you always put it on the timegrapher. My initial question was, if someone messed with those levers. Let's say they moved them both to one side, would you just leave them in the position that person put them in after service? Thanks for the response. I've asked others, and they think I'm trying to regulate my watch. I was only wondering if a watchmaker would need to do any adjustments to the balance levers after, or during service.

[@spidiq8]

@@1988banker Absolutely yes they'd need to be adjusted after service. While I say there's no default position what I mean is that they have to be roughly placed then adjusted on the timegrapher. I simply mean there's no preset mark on the balance that they'd be correct in. If moved it would throw the timing of the watch completely out.

[@1988banker]

@@spidiq8 Thanks for the answer! So you would roughly place them. With the beat lever and other one in the middle of the +-. Then adjust the beat, and after that the one to slow down or speed up? If the levers were never moved, and it was great on the timegrapher, I imagine nothing would need to be done. If the beat was good and it was like +1 a day you would be done. I imagine it depends on the situation. I do appreciate the response!

[@spidiq8]

@@1988banker Essentially yes but some adjustment would always be required after service once the oils had settled after a few hours of running. On the timegrapher you actually need to take positional readings and adjust accordingly. Unfortunately many watch reviewers on KZbin get one of these and don't really understand how to use one and just check the watch in one position and call it good. I really should do a video on using a timegrapher as I've had a few people ask about them. In short dial up and down should be very close then 6 high and 9 high are the next two most important positions as these are the most common in use. Provided they're within 10 seconds between these positions with something like a modern NH you're good.

[@Janet_Airlines802]

Thanks for the video, much appreciated. The moebius 9010 is for jewels, what's the D5 for ? The mainspring? Is there any other oil needed besides those 2? Trying to get everything together and I need to purchase oils, they're very expensive so I dont want to waste money. Thanks again.

[@spidiq8]

The 3 essentials are 9010, D5 (or HP1300) and a grease for metal to metal parts like the keyless works. 8200 is a good general purpose grease. For an automatic watch you also need a braking grease for the barrel walls of the mainspring. Moebius 8217 is a good 'general purpose' one. There are other greases and oils with specific purposes but you can cover most movements with those mentioned. Seiko has its own specific lubricants but I haven't used any so can't say how they are. D5 is used for the barrel arbors. 2nd wheel arbor jewels and the 2nd reduction wheel teeth which the pawl levers (magic fingers) bear on. 9010 for the 3rd, 4th, escape pivots and the balance jewels. (9010 can also be used for the pallets where they bear on the teeth of the escape wheel but the specified recommended is 9415 which is a semi liquid grease)

[@Janet_Airlines802]

@@spidiq8 thank you so much for the detailed reply, I greatly appreciate it.

[@paulperry8614]

What an interesting video. I am in awe of your skill, I would love to be able to do this. I know that you can buy these movements for a reasonable price so am tempted to purchase one but I need to do some study before I have a go at this. Do you have any suggestions of courses or distant learning courses I could consider. Thanks for posting.

[@spidiq8]

Thank you Paul. It's certainly something you or anyone with patience and a passion for watches can do, these movements are great for practice as, with many things it's better to start with something you know is good and working so you know what you're aiming for in the finished item. If you're on Facebook I highly recommend you join watch repair lessons group of which I'm an admin, there are lots of helpful folks on there with a huge variation in skill and experience levels, several who have more skill than myself and also people who've never so much as opened a case back. Mark Lovick who the group belongs to has a fantastic channel called watch repair lessons and also does a distance learning course which is highly lauded, you can find details of that here. www.watchfix.com/

[@paulperry8614]

Thanks for tip on the course I am seriously considering doing it.

[@HausOfCustomMods]

My balancing wheel is not rocking when I drop it in place. Why is that? It is a new spring and it is not bent or damage… it seems like I have put it in the right slot. It just doesn’t seem to beat 😢

[@spidiq8]

There could be so many reasons why. It's impossible to say without knowing more about your movement. Is it freshly rebuilt, is it an old one you're replacing the balance on, if so are you replacing the balance because you think the old was defective or damaged, does the wheel train run with the pallets removed and so on.

[@SanityOfficial]

Hey friend. I know its been a while but did you ever figure this out? Having the same issue…

[@MisterPorterandWatches]

Nice video sir! I have a question, my NH35 quick set date change doesn't jump but instead it moves very slowly when i keep turning the crown. would you have any diagnosis for that?

[@spidiq8]

should initially turn slowly but then snap over at or near midnight, if it doesn't it has become disengaged from the calendar wheel jumper spring or the spring is broken, to rectify you'll need to strip, dial, hands and calendar work cover plate. If it's a new watch, send it back for replacement.

[@pauldiplock205]

I wonder why they use plastic for certain parts? Cant be cost surely.

[@spidiq8]

Cost and ease of manufacture. Injection moulding once you have the dies is fast cheap and they can make hundreds at a time. Metal would need stamping and possible finishing of rough edges.

[@Danchik369]

Very nice video, thank you, I'm curious, where did you learn watch repair?

[@spidiq8]

Thank you. I was fortunate enough to have a mentor when I was in my early teens who guided me through the basics, an old guy who lived up the road and repaired clocks and watches for people and was well known. It began by me asking if I could watch him, when he realised I was genuinely interested in how they worked he said if I'm going to explain I might as well teach you. That's how it began. There was a period where it all went to the background as I got a bit older and interested in other things but I returned to it in my mid twenties buying old mechanical watches from car boot sales which could be had very very cheaply then as everyone wanted quartz and I'd work on them and sell them. I got interested in filming them after discover the watch repair channel and discovering that people seemingly liked seeing it.

[@Danchik369]

@@spidiq8 Wow, what a great story :), I'm happy and glad I found your channel, looking forward for more videos from you in the future. :)

[@icyhot9783]

This video needs to be 100% redone. Everything from not starting off with the stem and winding works to not explaining the lube used, etc. Also, there are several areas Seiko's manual states requires lubrication, which are not being addressed at all. I appreciate the effort in creating the video, but I ended up tearing it all down and starting over. Way too many missed areas for it to run right.

[@aveevelasquez5983]

Does that Japanese movement last a while just wondering

[@spidiq8]

The NH series of movements hasn't been or that long but considering it's based on gradual improvements to seikos base calibres 7009 to 7S26 and 7S36 and there are watches from the 70's still running well. I'd say so.

[@davelowey3074]

Hi i'm not on any facebook or instagram i'll have a think about joining.

[@spidiq8]

Ah okay. No bother if not. A couple of the watch groups are good if you do. I don't bother with Instagram myself. I did set up an account but I don't really 'get it'

[@silentfox8]

bravo!!!!!!!!!!!!!

[@alejandroarce8533]

❤

[@barnauletskirill8606]

Этот механизм гораздо сложнее orient 46943! Вы легко справились!

[@spidiq8]

Like any movement, it's really a matter of practice on them, these are so similar to the 7s26 you'd manage fine, also close enough to the Orient.

[@pizza.doctor]

these are gonna be the first movements i'll work on. Damn they are so ugly looking, and that positional variance.... Better to make mistakes on something cheap and mass produced before tackling vintage watches though

[@tech29X]

Just squirt some WD40 and if it doesn't fix it, move along...

[@spidiq8]

You might as well just move along then as I guarantee that won't fix it.

[@tech29X]

@@spidiq8 You're right. My comment was made with tongue in cheek. One of my automatics with NH35a took in pool water. Somehow crown was unscrewed. It started to slow down. I opened it up, removed to movement and soaked in WD40 and it died. So, I moved along... 🙂

[@spidiq8]

@@tech29X I see. I was replying in case anyone thought that was a legitimate thing to try. Thanks for clarifying.

[@tech29X]

@@spidiq8 Well, I can only attest that I tried and it did not work 😃However, I'm not certain as to why and I might buy a brand new NH35 movement just to test with WD40 to verify. I can't say for certain if the pool water already damaged it or if I somehow hurt it after removing the movement out of the case (my first time). Water Displacement formula#40 seemed like just the right thing for the job (light lubrication, clean spray).