Repair: Zoom-Nikkor 43-86mm f/3.5 Ai (3/3)

Hello, everybody! I am now down with the flu so I am going to keep this brief. I am usually resistant to sickness but lately, stress from work has been getting into me so that probably affected my resistances somewhat. I am feeling a lot better now but I will need to take the doctor’s recommended rest period of 5 days. After that, I will assure you that I will be back to my usual health and even better, I will practice kung fu again this coming spring so that my body will regain my old resilience to sickness. This is a tale of redemption for me and also for this special lens so read on!


Today’s topic is about a lens that many people would consider fit for nothing but parts due to it’s heavy fungal infection but I will show you that almost nothing is not worth a try as far as old Nikkors are concerned! Ladies and gentlemen, may I introduce to you this gem of lens: the Zoom-Nikkor 43-86 f/3.5 Ai lens!

img_1021It looks really great on a camera of the same vintage, don’t you think it looks sexy on this Nikon F3HP? I love the Nikon F3 and for me, this is the best manual SLR ever made.For those new to this blog, this is the 3rd and last part of the 43-86mm series that I made. The others can be accessed through the links below and I recommend reading them,too.

  1. Zoom-Nikkor-Auto 43-86mm f/3.5
  2. Zoom-Nikkor-Auto 43-86mm f/3.5 C

Now, you may wonder why I give such high regards for this lens in the introduction when some people actually consider this family of lenses as rubbish. I will tell you now that the lenses on this family all perform decently in every condition and it gave the convenience of having to do away with a 2-prime lens setup. True, the earlier versions of this lens, the Zoom-Nikkor-Auto 43-86mm f/3.5 and the Zoom-Nikkor-Auto 43-86mm f/3.5 C will NEVER match the charts of the latest kit lenses but do put into consideration the time that they were introduced and what the market had to offer back then which is basically nothing much and you will probably see this lens family in better light.

img_2184Now, this lens is a complete redesign of it’s predecessors in that it got a brand new optical formula and a redesigned lens barrel for the sake of ergonomics. Having worked on the 2 previous versions of this lens (this is part 3 of 3), I will tell you that the overall schematics for the lens barrel didn’t change much but it is totally different so no parts can be shared between these 2 versions.

Aside from the native Ai-spec compatibility and the obvious cosmetic changes, the inside of the lens was actually engineered to be much smarter than the previous version in that it is now much easier to work with compared to the ’60s technology of it’s predecessor.

Nikon listened to their customers back in the day so they improved the optics of this lens by a huge leap with technology that was never available to them in the early ’60s when the original version was designed. The new optics which debuted in the mid ’70s fixed what the customers have been complaining about all along – sharpness and lens artifacts. You can now be assured of sharp and very useable  images even wide-open. Stop the lens down to f/5.6-f/8 and the results are great! Distortion didn’t go away but we cannot do much about that for the time being. It is safe to say that this lens helped regain the trust of the people as far as Zoom-Nikkors are concerned.

img_2183The lens was in a terrible state when I got it. The fungal growth was so serious that you are not able to see what’s on the other end of the lens when you look at it from the front. I was lucky because none of this caused any serious permanent damage to the lens elements. It is not always like this by the way. There are times when the fungus will leave a bald spot on the coating even though the fungal growth isn’t really bad.

(Click to Enlarge)

As you can see from the sample images above which I took almost exactly 12 months ago, the lens is VERY capable of producing sharp images as long as you got the focus right. I am always shooting my subjects while I am on the move so some blurriness you see here is the result of nervousness and slow shutter-speed. With this technique, even 1/500s will result in a blurred image when you are not careful. The lens handles really well and I can say that this lens is great for street photography despite the fact 43mm can be quite lacking when compared to 35mm. Overall, it works for me because I do have the 86mm on the other end that I can count on when I need the extra reach and when I have no more time to swap my lenses. The moody picture of the scavenger and his trolley would not have been possible if I didn’t have a zoom with me at that moment.

Now, do you see the strength of this lens? It gives you convenience at the cost of distortion and some image quality but it does render really nice. This combination is probably why it was used in filming the original Star Wars movie (along with other Nikkors).

The minimum focusing distance can be quite annoying at times so please bear this in mind because 1.2m is really too far for close-ups. This can be fixed by using an extension ring or a 4T close-up filter but I just couldn’t be bothered with it. The results are said to be good with these options.

The focus throw also felt awkward because it is too long for both 43mm and 86mm. So long as you don’t need super fast focusing you will be OK. I am not sure why the focus throw is that long but it has always been like this since the first version of this lens. You will soon get used to it after an afternoon using this lens in the field.

Would I recommend this lens for daily use? Absolutely! So long as you are aware of all of it’s constraints then you can make them work for you instead of them being the way. For collectors who just need to have everything, I am sure that you already have one in your collection if not then shame on you for skipping such a historic lens from Nikon.

That’s it for the introduction, let’s begin with the teardown!

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.

Disassembly (Lens Barrel):

OK, this will be long and confusing so please pay attention. Zooms are more complicated than primes by design because the lens barrel also needs to zoom in and out and keep the lens assemblies inside in sync.

You will find that I will go back and forth frequently on this lens because as I didn’t know the correct order for taking this thing apart but I edited the order of my pictures so that it is easier to follow for people who are unfamiliar with this lens. You will think that I will be more knowledgable than this after working on the other versions of this lens family but I will tell you now that each lens is new to me the first time I work on it.

The biggest gotcha of this lens is the rear helicoid. Be sure to take plenty of notes and also observe how things are put together before you remove anything. I can tell you that it will be very frustrating if you got it wrong.

img_2185Begin by unscrewing this set screw. Be sure to keep this safe as they are so small they can be easily misplaced, some are so small that they resemble poppy seeds!

img_2187The set screw secures the front ring. The front ring is usually glued so you may want to use a bit of solvent or acetone to dissolve the glue. Use a grippy rubber glove and that should give you enough friction to unscrew this with your bare hands.

img_2190With the front ring out of the way, the rubber sleeve can easily be removed. These are held in place rubber cement so run a toothpick underneath it’s circumference to un-stick it.

img_2200Now, remove these set screws and if I recall this properly there are 3 of them. You see that red lacquer used as thread lock? It’s very popular here in Japan and dissolves in alcohol so I would place a drop of alcohol on these to soften them up before I remove them.

img_2188Now, the front elements group is connected to the helicoid and the whole assembly is also connected to the focusing ring. Mine was glued so I had to use a lens spanner on the slots.

img_2189Be very careful not to damage the front element!

img_2204as the usual with helicoids, NEVER forget where it separates from the rest of the lens. You will have a hard time getting this back if you didn’t mark where they separated. For this, I made a small scratch on the black paint to mark where the infinity sign is when this thing separated from the the lens barrel.

img_2202Now that the rubber sleeve is gone, you can now unscrew this to separate the focusing and zoom ring. Forgive me, but I forgot how many screws there are to remove in this step as it has been around a year since I worked on this lens!

img_2203The focusing ring can now be removed. Before you separate then, make sure to mark it so you will know where it should be in reference to the lens’ midline/infinity line.

img_2191Now, off to the rear! Remove these screws using a long-shafted JIS screwdriver. Make sure to exert enough force by using your elbow’s weight to prevent stripping these. They will be tough to remove because 1 or all of them will have some sort of thread lock applied to the screws and if it doesn’t move, place a drop of acetone or MEK and let it work on the stuff before you attempt to remove it. Now, some people will use a butane torch for this and it’s totally OK. In fact, I do it sometimes myself as a last resort.

img_2192The bayonet mount can easily be removed now that the screws are gone. There are nothing that would get caught so there is nothing to watch out for.

img_2224The bayonet assembly consists of these parts. I advise you not to open this up unless it’s in a really bad state. The slots on the brass ring holds some bearing balls and in more higher-end lenses, this would have bearing balls running the circumference of the lens. This is a cost-cutting decision but it’s still nice that it has it. I assume other brands wouldn’t care.

img_2193Now, before you start removing the aperture ring be sure to remove these 2 screws first. It can be tempting to remove the aperture ring at this point but you will risk damaging this if  you forgot to unscrew these. These 2 screws connects the aperture fork found inside to the aperture ring.

img_2194Use a sharp compass to remove the rear elements group. It is very vulnerable at this point and it’s a good idea to keep this in a safe place while you’re working on the rest of the lens. You can remove the aperture ring at this point if you wanted to but I’ll leave that for later.

img_2195Store the rear elements group in a safe place. Man, just look at that growth! Disgusting!

img_2196OK, now is the time that we are waiting for! We can safely remove the aperture ring! Don’t know why I didn’t remove it as soon as I got rid of the screws but here it is.

img_2197Now, this is very important so pay attention. With the lens focused all the way to infinity and zoomed all the way out to 43mm, take some notes on this screw’s position. It should be like this when you get your lens back. I know that there will be some variations between lenses when it comes to tolerances but that is why I am encouraging you to take notes!

img_2198Do take special notes from the other side as well. This part can be frustrating if you got it wrong so take your time and take plenty of notes!

img_2205OK, now that we have removed the front and rear elements group and set them aside we’re now safe to work on the rest of the lens without thinking much about them.

Now, back to the front part of the lens! Remove this tall-headed screw and be careful not to strip the head by using a driver that would fit the slot PERFECTLY. It is very amusing to see that this little thing controls the push-pull and focusing action of the lens.

img_2206The focusing barrel can now be safely removed once that screw is gone. Yuck, how filthy!

img_2208Now, for the 2nd elements group use a lens spanner with the long bits installed so you can reach these slots. If yours was glued then you may want to do the acetone routine on this. I was really skeptical at first when I saw the fungal growth but it will be gone later.

img_2209My fingers fit inside the barrel so I just picked the 2nd elements group up with my fingers.

img_2210Do the same for the 3rd elements group but this time, be careful which slots you should be using. I encircled the correct one so you will avoid opening his up by mistake.

img_2211Again, since my fingers fit into the lens barrel; I simply picked the thing with my fingers.

img_2214Now, on to the more complicated part! These 4 screws secure the basket inside, The basket as I call it holds some of the elements group and keeps it in place while the rest moves as you zoom or focus in or out. This is a common part on many of Nikon’s zooms of the era.

As you can see from the picture above, the spacing is different which can only mean that the legs of the basket is not symmetrical. Take note of that to avoid headaches later on.

img_2215Once the screws are all gone, the basket can now be removed safely. It is also noteworthy that the legs of the basket function like some kind of rail that keeps the iris mechanism’s assembly (including the elements group connected to it) in place when you zoom in or out if I am not mistaken so it’s proper alignment is crucial. Don’t worry, it’s not that scary!

img_2213Now, time to remove the decorative sleeve with all those colourful lines. There are exactly 3 screws that secure this so you will have to get rid of those first before you can remove it.

You can remove this part earlier id you want to but I just did that now. You see that slot in the center of the image? That slot had a leaf spring that controls the tension of the zoom and focusing action. If you want it to be stiffer, just bend the spring until you got what you want but be careful not to make this too tight and make your lens a pain to use.

img_2221The sleeve and the chrome ring comes off like this. You don’t have to do this but I just had to just to make sure that everything is clean before I put this thing back together.

img_2212I am not sure if the spring has to be removed in order for you to go on but I just did it out of wanting to clean this lens thoroughly inside and out since it is in a very filthy state.

img_2216Now, on to the most frustrating part of the lens – the rear helicoid! This part is common to all the lenses in the this family and it’s such a pain so please be careful and take plenty of notes before you dismantle anything!

I made a mark here so that I know that this is the correct position when the lens is zoomed all the way out to 43mm and focused to infinity. If I got this right during reassembly then I am safe, at least for this part of the lens. It will get more complicated later, trust me.

img_2217Remove the screw that secures this ring and get it off the rear helicoid. This ring is used to hold a pin that acts as a cam and you can see that picture in the earlier steps.

img_2218And now, the most delicate part of this operation!  Before you remove the iris assembly, do a lot of observations on how high this should be inside the lens barrel and most important of all – how it separated from the rear helicoid and it’s position in relation to other parts in the interior of the lens barrel. I can imagine that many beginners get this wrong.

img_2219Now that the iris mechanism and it’s helicoid is off, we can now remove the rear helicoid. Make sure to take not where it separates. This is where mine separated, see the marks? Do not be a LJB (lan jiao bin) and scratch your head later after the fact!

img_2220With all those out of the way, we can now pull this cup off from the lens barrel. This cup is what’s holding the optics together as it slides in and out of the lens barrel. Notice the leaf springs? I would suggest leaving these alone as altering the tension of these is not advised.

Disassembly (Objective):

Well, we don’t have a proper casing for the objective as far as zooms go since it is designed to be integrated into the main lens barrel. This part is not difficult at all but just make sure that the lens elements are facing the correct direction when you reassemble the lens later on or you will have to open this thing again just to flip one single lens element.

I’ll apologise to you now because I forgot to take pictures of the rear elements group! I was probably too busy with lens so I forgot to take any pictures of it’s disassembly. I’ll tell you now that there’s nothing special with it and once you have gotten this far anyway you will definitely have the skills and experience to figure this on your own.

img_2222The front elements group can be accessed by removing this ring. Be careful not to drop any of the elements into the floor as they can free-fall now that nothing holds it together!

img_2223The front elements group consists of these parts. Be specially careful with solvents as the front element is made up of 2 separate glass elements that were glued together and you do not want the solvent to ruin the glue!

img_2227This elements group can be disassembled just like this.

img_2228Be careful which side this element should be facing when you reassemble your lens later.

Disassembly (Iris Mechanism):

As far as iris assemblies go, this one is unremarkable. There are no special tricks used on this and you can be sure that this is going to be a breeze as long as you made a lot of notes.

img_2226This ring on the iris assembly can easily be removed with just your bare fingers.

img_2225These screws secure the iris mechanism inside. Before unscrewing these, make sure that you made adequate notes and marks on ring inside this thing.

img_2229With those screws gone, you can simply pick the ring off of the iris mechanism. Be sure to not damage the iris itself while doing so because the blades are very delicate. Notice that thing to the left? Make you that you took pictures of it before you take this apart. The legs on that thing has to be in the right place when you put it back or else the iris will not open or close properly.

img_2230The ring secures the rotating plate and this plate that is in charge of constraining the iris’s movement as you open and close the iris using the aperture ring. Did that make sense?

img_2231This rotating ring is connected to all of the iris’ blades and it opens or closes the iris as you rotate it. That tab sticking out from the side is what’s connected to the stop-down lever.

img_2232The blades can now be accessed. Use a tweezer to carefully remove them one-by-one or if you are lazy like me, simply drop these into the palm of your hand.

As you can see from the pic, there is nothing wrong with the iris mechanism and I usually skip this because it’s just so much bother trying to put these back but since I intend to do a thorough cleaning, this thing had to be opened-up.


This lens is something that I will never consider working on as a lazy Sunday’s afternoon’s project. As you can see, it can get complicated enough as it is. Now, if all you want to do is to clean the lens elements then this will be quite an easy project since you can access all of the glass elements without having to open this thing to it’s bare components. There are a couple of Nikkor zooms that work the opposite of this meaning you have to disassemble it to a certain degree before you can access the innermost elements.

For the beginner, this lens will teach you the ins and outs of a classic Zoom-Nikkor design as it’s design is mostly the same with other Zoom-Nikkors lenses in principle. And if you did not take notes on the rear helicoid part then it will teach you to be more careful next time! There are no soft kiddie gloves for lens repair, any mistake is paid for by money and if this isn’t your own lens and if you aren’t comfortable with your skill yet then skip this and practice more with primes until you develop the discipline required to handle that rear helicoid assembly. I know that I am making this sound like a big deal because it is!

img_2233Here are the major parts of the lens minus the lens elements. It’s such a complicated little gem that one wonders why and how this became Nikon’s budget zoom back in the day.

img_2188To calibrate the infinity focusing of this lens, simply reassemble it but leave out the front ring and the 3 long set screws that secures the front elements group to the focusing ring. It is a simple exercise for this lens so don’t worry. Now, focus all the way to infinity and with the aid of the focus confirmation dot on modern Nikon Cameras, focus on something around 6km or further. Turn the front elements group assembly until the focus confirmation dot is solid. Now, if the focus confirmation dot lights up solid then you got it squarely where it is supposed to be. Now, try zooming it to the other end and see if the focus shifted or not. I am not sure if this lens exhibit some focus-shifting tendencies as you zoom. If the focus is still spot-on on the other end of the zoom then you nailed the focusing of this lens. Once you are satisfied with the results, tighten the 3 set screws to secure the front elements and focusing ring together. Shoot and confirm focus at various distances just to be sure.

img_2235Fungus-free! The haze you see here is just condensation and it went away overnight inside a dry box. The lens is now very useable and respectably sharp at any aperture!

img_2263Just to make sure, I had this little thing facing the sun for hours to kill whatever is left in there. Sure, all that mechanical cleaning will get rid of the fungus but I just wanted to be safe just in case. Just take a look at how it was before I cleaned it and it’s understandable.

I hope that you enjoyed this write-up! I was hoping to write you a higher quality blog post but the flu is really taking a toll on me. I do feel better now, unlike 2 days ago where I just feel miserable and helpless. This lens stands for “revival” as far as I’m concerned and with that spirit, I wish to see my health get back to it’s former vitality and I hope – even better than before! Thanks for the support and donations, they are what’s giving me the mental strength to keep going, 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.


4 Comments (+add yours?)

  1. Gugo Junior
    Feb 09, 2017 @ 18:45:31

    Richard my friend, I just found you website, and I have to say it’s THE BEST site on nikon’s stuff on the internet, i just subscribe and I”ll take all my extra time to read start to finish. It’s really amazing. I’ll learn anything I can, any info you drop. Thanks! Best brazilian regards, and keep going.


  2. Trackback: Internet Nikon Repair Resources – My Take on Photography and Diving (Underwater Photography Mostly)
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