Repair: Nikon S2 Front Overhaul

Hi, my beautiful readers! I was considering skipping this weekend so I can rest and since I did a report on CP+ 2017 last week I felt that I can wait for next week until I publish a lens teardown that I am currently writing. I do listen to my readers and friends and there was a considerable interest on the subject of this week’s article so I decided to write this instead and publish it this weekend. You guys know how much you mean to me so I can’t object.


Remember that I mentioned in my CP+ 2017 post that I almost got a Nikon rangefinder but I lost the chance to get one because somebody beat me to it and I was hesitating? Well, that is probably a good thing because I got a Nikon S2 that was fated to end up with me for the rest of my life! I walked past this camera for days in the bazaar, I always looked at it and I felt as if it was beckoning me to take her home and I felt a weird attachment to it. Imagine that this camera was mine in my previous life and it found it’s way back to me for a CLA in my present life. That’s probably a better story than “Somewhere in Time”, would you agree?

img_3490What a lovely little camera and it came with the standard Nikkor-H 5cm f2 lens. It has a “C” engraved on it denoting that it was coated with ancient lens coating technology that isn’t up to snuff compared to current ones but that was a big deal in the olden days. This lens is sharp and has acquired a good reputation but that belongs to another write-up!The Nikon S2 is very robust, reliable and a fun to use. It has Nikon’s brightest rangefinder. I tried a Nikon SP and the view is tiny compared to this but unfortunately the viewfinder of the Nikon S2 is fixed to 50mm and non-parallax corrected. The handling is a bit quirky,too. It has separate dials for slow and fast shutter speeds and you have to sync them together before you can user it at the correct speed while switching from slow to fast speeds. You’ll also need to reset the film counter manually every time you load a fresh roll of film but the advance is automatic so I guess this is OK. You have to remember, this was sold in the mid ’50s and it was designed  a couple of years earlier so this was probably the best that Nikon had. Even with all these annoying quirks, the Nikon S2 is a big leap from it’s predecessor and is said to be the best Nikon rangefinder to use in terms of ease and simplicity.

Above is Tony Bullock’s video about the Nikon S2. He was helpful in answering my questions about Nikon’s  rangefinders. His video shows how to operate the Nikon S2 and some of it’s defining features and I suggest that you watch it.

I got this for a reasonable price from a camera bazaar since it is near the end of the bazaar. It was sold to me for almost 30% off the list price. The camera itself isn’t perfect. Scratches can be found in the baseplate, a ding here and a scruff there but other than that there isn’t anything wrong from a cosmetic and mechanical point of view.

I did find that the rangefinder was a little bit off in the horizontal plane and the helicoid is a little bit dry and squeaky. You know me, I will not let this pass. I also thought that this’ll be a good opportunity to add this to my Nikon repair database and maybe help somebody in need of a write-up for the Nikon S2 and how to repair or maintain one.

img_2317Time to bring out my cheat sheet! Good thing I have this. It didn’t explain much so I had to find how some things work myself. It’s better than nothing though and I find the section for a shutter replacement very helpful and I think that was the intent of this repair manual and not the usual front CLA that we want to do. I call this front overhaul because we will be opening up and cleaning the front parts of the camera. I was into cars and maintaining the valves and tappets of an engine is called a “top overhaul” because these parts are found on the upper part of the engine block and I just borrowed the term and logic from that.

Anyway, let’s begin with the front overhaul!

Before We Begin:

If this is the first attempt at opening a lens then I suggest that you read my previous posts regarding screws & driversgrease and other things. Also read regarding the tools that you will need in order to fix your Nikkors.

I highly suggest that you read these primers before you begin (for beginners):

Reading these primers should lessen the chance of ruining your lens if you are a beginner. Also before opening up any lens, always look for other people who have done so in Youtube and the internet. Information is scarce, vague and scattered (that is why I started this) but you can still find some information if you search carefully.

I highly recommend that you also read my working with helicoids post because this is very important and getting it wrong can ruin your day. If I can force you to read this, I would. It is that important!

For more advanced topics, you can read my fungus removal post as a start. This post has a lot of useful information here and there and it will be beneficial for you to read this.

About Me:

I am a photographer based in Tokyo who scours the junk section of the camera shops here on a regular basis. I started this hobby of fixing old lenses and cameras because I kept on getting scammed before when I purchase online. This turned out to be a blessing because I now buy junk lenses for a fraction of the price and then fix them to add to my growing now collection. This allowed me to buy gear that were otherwise off-limits to me if I were to get them in better condition.

I was a scale modeller before who built models for other collectors for a very longtime, got an education as a dental prosthodontist (but didn’t pursue dentistry) and growing up in a watch repair shop gave me the useful skills that would help me in this craft. Fixing my car also contributed some know-how.

Having mentioned the above, I will tell you now that I am not a professional repairman! So please take what I do with a grain of salt and I will never be held responsible for anything wrong that will happen to you and your project. I hope that the pros would guide and teach us but nobody is writing anything.

As my collection of repair notes grew, I get requests from people with similar interests and from professionals who just needed some notes just in case. Now, I am sharing my library with you for your entertainment and reference. I hope that you find my work useful.

Calibration (Rangefinder):

To determine wether your rangefinder needs to be re-calibrated, focus to infinity and look through your viewfinder and see wether the rangefinder patch is solid or showing double images of an object that is very far (5km or more). The object in which you want to focus on to has to have clear vertical and horizontal lines and a building will be perfect! If it is off by a bit then your will have to calibrate yours. Mine wasn’t perfect but it was working fine, I can live with it to be honest but I just saw this as a chance to tinker with my Nikon S2 and show you how I did it.

Remember, just like lenses, if you got the infinity focusing wrong then it will affect all of the distances down the scale. What’s 1m in the scale can actually be 1.2m if you get what I mean. This is not an SLR so this makes nailing the focus even more important!

As far as difficulty goes, I will say that this is pretty easy provided you have a steady pair of hands, the right screwdrivers and some know-how with working with mechanical things. I will caution you that you should be very careful not to scratch anything on this and if you need to, cover the surrounding areas of a screw with masking tape to help guard against an accidental scratch. You want to preserve this camera not punk it!

img_3491First, carefully remove these 4 screws at each corner of the front bezel and never forget to set the distance to infinity just in case so nothing moves as you are doing this. You have to use the a driver that perfectly fits on the screw head’s slot and if your’s doesn’t then make that driver fit by using a file. You see, the screws are so prominent that if you ruined that nice chrome plating or damaged that screw head somewhat then you will have to give the camera a new name – “scarface”.

img_3493Now, you have to remember that one of the screws is NOT like the others. The screw found on the upper right hand corner of the camera is longer than the rest, don’t forget this.

img_3494Once all 4 screws are gone, carefully lift the front bezel from the bottom of the camera. It will not go any further, however. The saw-tooth wheel and it’s locking lever is in the way that’s why. Do not force your way or you will warp the front bezel, it’s delicate.

img_3495You will have to carefully maneuver this corner of the bezel so that it can come off. Press the locking lever to help you get that bezel off. Be patient.

When putting this back, never over-tighten the screws on the bezel or else you will leave a depression around the screw and it looks ugly. Do you want that?

img_3507Now, time to recalibrate my rangefinder! This is a delicate piece of precision instrument so be sure to handle this with care. The viewfinder mechanism can be calibrated like this and this makes routine maintenance a breeze. However, to fully calibrate the rangefinder, you will have to open the top panel to access some other important parts in the mechanism.

I have outlined 3 things that you will have to play with in order to calibrate your viewfinder and the order that you should go about working with them. I will have to warn you that you should work in the order that I outlined in the list below this because the adjustments are all interdependent of each other. Fixing #3 first and then going to #2 will NOT work since they are connected to each other and will throw #3 out of calibration. Confused now? Just follow my sequence and you should be fine. I colored it in RGB to make it easier to follow.

  1. First, loosen the Tightening Screw (TS) for the Vertical Adjustment Wheel (VAW). You do not need to loosen this too much, a few turns should do the job. The screw is delicate and old so be careful and use driver that perfectly fits the slot on TS’s head
  2. A word of advise, the VAW is deep inside the hole so be patient while working with it. Removing the top cover will give you better access to it but that’s too much work for a routine maintenance job. Get a thin plastic toothpick and pick on the VAW until the image lines up vertically in the rangefinder patch. What I did was I have the camera in my face and focused it on an aerial (antenna) around 4km5km from where I am. Be sure that the helicoid is focused all the way to infinity for this. Now, with a careful flick of my toothpick, I carefully adjust the wheel until the aerials are focused and not displaying any double image at all. After you’re satisfied with your results, tighten TS and be careful NEVER to over-tighten this. That’s all for the vertical adjustment part.
  3. Finally, we are at the last and easiest step – the horizontal adjustment. Again, I focused the camera on the aerial (infinity) and with a flat-head driver placed squarely on the Horizontal Adjustment Screw (HAS), I carefully turned the HAS until I am satisfied that the horizontal lines are all perfectly on top of each other. That’s it, Good job!

Now, wasn’t that easy? It is tedious, I know but it can be worse for cameras from the other brand. If all you want to do is to calibrate your rangefinder then skip the next section as it involves working on the helicoid (helical to some).

Disassembly (Helicoid):

Now that you got this far you might as well clean the helicoid. Mine was squeaky and dry. It was intended to be this way so the wheel can be turned quickly without resistance. At this point, you should make a conscious decision, do you want a quick-turning wheel but have a dry feeling helicoid or have nice and smooth helicoid and a damped focusing wheel. If you guys have been following me, you will know that I will choose the latter because I prefer to focus using the helicoid. The wheel will be damped but really, it’s not by much and you can still turn it effortlessly. I may be over-exaggerating when I said that the focusing wheel is going to be heavy but it all depends on your choice of grease and how much you apply it.

This was easy for me but like working on helicoids in lenses, you will always want to mark where it separates. I will not be scratching the beautiful finish of my camera so I am using a permanent marker for marking this.

img_3496First, carefully remove these 4 screws securing the mount. Be careful never to damage the throat of he mount because it is visible and all of the beautiful numbers are engraved on it.

img_3497Now, the focusing wheel and it’s mechanism if free-turning so you will not have to worry about it being off but just to be sure, I marked which direction should be facing down. I’ll wipe the ink later with alcohol and tissue so I don’t leave anything permanent.

img_3498You may be tempted to remove the mount as soon as you got rid of the screws but just wait for a bit and examine it first before you damage anything. The locking lever is on the way so you will have to depress it and fiddle with it until you can safely get the mount off. It is a tight fit so go about removing this in small increments using your bare hands.

img_3501Once the mount is gone, you can now access this gear. This is part of the focusing wheel’s assembly and it’s connected to the helicoid directly. I used a cotton swab that was soaked in lighter fluid to clean up whatever gunk is there. I then lubricated it with machine oil for cameras. A little goes a long way and all I needed was to apply a small drop using the tip of my precision screwdriver. Capillary action will take the oil where it’s needed. Remember, never over-lubricate anything when working with oils! I remember my days as a kid in my grandpa’s watch repair workshop and we would even use a needle tip to apply a drop of oil to the cogs inside a watch movement. If you overdid it, the oil will spatter here and there. Now, turn the wheel so that you condition it with the fresh oil.

img_3499OK, here is the helicoid. This is very different from what we have been seeing so far on our lens overhaul articles because the male threads are serrated. See the spring to the right? It is there so that the locking lever goes back into position automatically. Study how it works and appreciate this mechanism before you dismantle it.

img_3502Just like the helicoids on a lens, this thing also has a helicoid stop. It’s there so that it won’t go past it’s focus range from 3ft to infinity. Remove it so you can separate the helicoid.

img_3503Now that the helicoid stop is gone, you can now separate the helicoid from the mount. You’ll have to press the locking lever so that the helicoid is unobstructed. This one separated here at around the 3ft mark. I looked at the female half of the helicoid and I counted 3 positions where the helicoids will mate so be careful and use a pen to mark where yours separated!

img_3505Just look at that, what a work of art. That groove that you see here is where the helicoid stop and the focus lock reside and how it limits the movement of the helicoid. It looks clean and dry. Nikon intended it to be this way, I guess.

img_3506Now, here is the other half. I carefully cleaned these with lighter fluid and alcohol just to make sure that no residues are left. This is a difficult part to mill and this is one reason the S-mount was so complicated and costly to manufacture.

I lubricated these with the lightest grease I have and I only applied a thin film of grease. It is not a good idea to over-damp this mechanism as it will affect the focusing wheel. If you want to strain your finger then it’s your call.


This will be a great exercise for a slow Sunday morning. These cameras are great, they were made tough like VW Beetles in that they will function forever so long as you maintain these properly. Now, compared to the cameras from the other brand which needs maintenance from time-to-time, this camera will run for decades without one and the one that we just did together here is probably all that this camera will need for a very long time. Yes, she’ll “love you long time”. Long after your tired of her. Cameras are a man’s best friend.

I was also told that because of the exposed nature of this camera’s helicoids, the helicoids is prone to gum up after a couple of months after lubrication due to dirt getting mixed with the grease so Nikon decided that it should run dry. We will see how it goes, I am willing to lube this again when it happens or just strip the grease altogether and use a different type of lubrication (dry type).

img_3508I can never work with feet so I used a red marker and drew numbers that correspond to the metric equivalent of the important distances to me on the scale. I can use alcohol to wipe these off later if I wish. If you want to you can even use dry transfers, decals or print a ring on a sticker and tape it over the scales so you have a nice metric scale. I know, I am lazy.

img_3509Nice camera. Japanese curry doesn’t use cumin so your armpits won’t stink. I ate samosas for a week before because I was vegetarian many years ago and samosas were cheap and as a consequence of that my armpits stink. It’s the food! You smell of what you eat!

Overall, I am having lots of fun with this little camera. Sure, it’s quirky and awkward. It is going to slow you down considerably but maybe that is a good thing for me since I am used to fast snap-shots of people. I find myself using a slower shutter speed because of this and I can stop the iris down more for more depth of field. The shutter is so damn noisy and it is attracting people’s attention at times.

Thank you very much for reading this, I hope that you enjoyed it and share this with your friends. There sure is not a lot of things online for the Nikon S-mount so I hope that this is going to find it’s way to somebody who needs this the most. I am contemplating wether to make more S-mount related stuff in the future but as you all know things aren’t cheap in Nikonland when it comes to rangefinders. Thanks again for your support, Ric.

Help Support this Blog:

Maintaining this blog requires money to operate. If you think that this site has helped you or you want to show your support by helping with the upkeep of this site, you can simple make a small donation to my account ( Money is not my prime motivation for this blog and I believe that I have enough to run this but you can help me make this site (and the companion facebook page) grow.

Helping support this site will ensure that this will be kept going as long as I have the time and energy for this. I would appreciate it if you just leave out your name or details like your country and other information so that the donations will totally be anonymous it is at all possible. This is a labor of love and I intend to keep it that way for as long as I can. Ric.


21 Comments (+add yours?)

  1. Peter
    Mar 08, 2017 @ 05:32:25

    Hi, nice write-up! I’ve done this to several Nikon rangefinders and your instructions are thorough and correct. One thing I noticed is that your Nikon’s helical mount wasn’t shimmed. Often, but not always, there will be very thin washers under each screw between the mount and body. It’s very important to note the location of each washer and return it to it’s original position when placing the mount back on the body. If not, the camera will never focus optimally.
    Also, I never use grease on the helical. I prefer a thin coating of graphite or nothing at all. This is a personal preference since I like to focus using the focus wheel and it works best with a dry helical.


    • richardhaw
      Mar 08, 2017 @ 07:16:17

      Thank you, Peter!
      I got a cheat sheet so that helped me find my way through the whole thing.

      Yes, here in Japan many people use graphite that can be bought from the tripod section (for ball heads) for the helicoid. They told me that if the helicoid is damped, the focusing wheel will wear faster.

      As for the washer, I don’t have anything at all! Maybe that is the reason why I am having inconsistent readings from the RF. I am pretty good at calculating distances up to 4m accurately by eye so I notice there is something off. I will check my repair manuals for how these things look. I hope that I can find a similar gauged shim. Thanks, Peter for the guidance. I really appreciate that! I hope you don’t mind me adding this to the article. Ric


  2. Peter
    Mar 16, 2017 @ 22:47:21

    Shimming yourself would be very hard without the right equipment. At the factory, each camera was placed on a specialized device to measure focal flange distance. If the distance was not within tolerance across the whole image plane, the mount would be shimmed with very thin washers wherever needed. These shims were fractions of a millimeter in thickness. You might find one to three shims under one mount screw, and sometimes no shims were needed. Evidence of misplaced shims would be uneven sharpness across the image plane, or focal point inconsistency. In general shooting situations you might not notice. And again, your Nikon may not have needed them.

    Best of luck!


    • richardhaw
      Mar 17, 2017 @ 00:59:19

      Thanks! Unfortunately I found no shims at all. It’s either the previous guy lost them or mine never needed them at all. I am not overly-concerned by the fact but I do have 2 crude devices at home for collimating and I will try to modify it for chart testing and see wether the focus plane is OK. I will be doing the same on my S3 and S that I both got as junks and I hope that they are shimmed if ever they need to have them. Shutter replacement might be a bigger job to look forward to on the S. Ric.


      • lenshacker
        Mar 23, 2017 @ 00:17:21

        I had the problem with one S2, and found that “MWS2” machine washers could be used for the helical. With this particular S2, I shimmed it and adjusted the rangefinder to use it with Contax lenses. Worked well enough to use with a ‘C’ontax version of the Nikkor 13.5cm F3.5. It usually has a Zeiss Opton 50/1.5 on it.

      • richardhaw
        Mar 23, 2017 @ 06:29:12

        I see! I think that I am fine where I am at now with my S2. Thinking about it now, my collimation aids will probably NOT be adequate for this level of fine adjustment. Checking things out at infinity is one thing, checking charts by eye is another. Ric.

  3. Jon
    Mar 19, 2017 @ 11:18:35

    >It has a “C” engraved on it denoting that it was coated with ancient lens coating technology that isn’t up to snuff compared to current ones but that was a big deal in the olden days.

    Congrats on the S2 and Nikkor-H 5cm F2. A fine first step into the world of Nikon rangefinders! Regarding the lens coatings used on Nikon rangefinder lenses, the quality is actually very good, and the coatings are generally hard and resistant to scratches. Certainly superior to coatings used on Leica/Leitz lenses of the same period. I’ve heard that Nikon gained a lot of their lens coating know-how from their experience coating submarine periscopes before and during WW2. I cannot vouch for the accuracy of that information, but considering that Nikon did indeed used to make optical components for the Japanese military, it is certainly a plausible story.


    • richardhaw
      Mar 20, 2017 @ 13:24:52

      Hello, Jon!
      Yes, Nikon’s coatings are tougher than Leica’s. My S.C ghosts and flares. I get a pinpoint ghost when there is light hitting the lens from the side. Maybe I should use a shade! The flare is of the veiling type, which can be pleasing depending on the person’s taste. Ric.


    • richardhaw
      Mar 20, 2017 @ 13:25:37

      By the way, My collection has grown! I will make a full overhaul article for the S, including a shutter change.


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  12. Robert Lilley
    Sep 16, 2018 @ 16:33:24

    I have an issue whereby the thumb wheel turns the helicoid – the lens assembly goes in and out but the rangefinder image stays the same and does not move. I conclude the the rangefinder is separated from the helicoid so does not register. Based on your article, the first thing that comes to mind is the locking screw for vertical adjustment has loosened and the VAW is not turning. Does this make sense to you? Do you have any other suggestions or concerns about this particular problem? Your article is great and has really helped me understand this mechanism! Thanks!
    Rob Lilley
    Belvidere, New Jersey


    • richardhaw
      Sep 16, 2018 @ 22:19:54

      Hello. Glad that you liked it. It sounds like it has been uncoupled. the only thing I can think of is the rangefinder assembly got stuck due to grime or corrosion. that thing needs a CLA. Rick.


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