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Repair: Zoom-Nikkor 43-86mm f/3.5 (1/3)

Hello, everybody! I hope that all is well with you. I am not feeling well the whole week and I am not sick as well as I write this post. Thinking about my readers and seeing my page view spike on the weekends by people anticipating a post gives me the encouragement to write this. Imagine Hulk Hogan rising up again after getting pinned by André the Giant in Wrestlemania III (after hearing the crowds chant his name). I know the feeling now.

I also made a Facebook page so that people can follow any updates that I made on this blog as well as serve as a venue for people to ask and talk about Nikkors and their maintenance. Just click on this link and “like” the page.

Introduction:

Today, we are going to discuss the “legendary” lens that started the small mid-range zoom trend, the Zoom-Nikkor 43-86 f/3.5! You can find many reviews on the internet for this lens so I am not going to discuss it’s performance here in detail. Besides, that is not the goal of this blog as we are more interested in the mechanical side of things.

This lens was made and designed in the early 1960’s to accompany the entry-level Nikkorex line of cameras as a built-in lens. Later, Nikon decided that this lens was worthy enough to carry the Nikkor name so it finally debuted as a separate optic for the F-mount. This lens is said to be the best selling zoom of all time, only to be superseded in sales by the amazing Nikkor 24-70 f/.8 AF-G  (which I own) lens several decades after.

IMG_2031Many people are divided in their opinions about this lens. Some people say that this is the worst lens that Nikon has ever put their name on because of it’s flaws while some would say that this lens is a success and deserves the title “legendary” because of what it did and what it signifies. I tend to fall on the latter because this lens revolutionised the way how many people used their cameras. Having this lens alone is enough to replace the 50mm and the 85mm in your bag while still having a little bit more on the wide end at 43mm in case you need something a bit wider. For photojournalists covering news at daytime back in the days, this meant that they would not have to miss a shot because they were changing their lenses or switching cameras.

The lens has the integrated one-touch zoom and focus ring (push-pull) that I like a lot and is ergonomically great. The balance is good and it feels substantial to the hand. I know this sounds silly but all this will give you more sense of confidence when you take the shot. The same thing can be said for a well-balance bike or sword in that you have total control over your tool as if it is a natural extension of your body. Ergonomics is a big thing!

(click to enlarge)

As you can see from the pictures above, this lens provides a very natural normal-wide POV at 43mm while also giving you the reach and compression an 86mm lens would give you at the long end. This lens is very versatile for street photography and the only shortcoming I can see is the rather long minimum focusing distance of 1.2 metres. I would often focus all the way down to 1 metre and take a picture of my subject’s face that close. While this is not a deal-breaker for me it does affect the way I shoot street in many subtle ways.

Sharpness is not so bad in my opinion. It is very useable in digital and certainly OK for film so do not worry too much about this. It is acceptably sharp wide-open and looks decent at f/5.6 and good at f/8. My pictures above are not good metrics for sharpness as I shoot while walking past my subjects in a very fast manner and a bit of motion blur is acceptable in my technique.

The biggest weaknesses that I can think of is the rather poor flare and ghost reduction as well as the terrible distortions that this lens has throughout it’s range. I may be asking too much from a lens that was made in the early 60’s! I am going to say this – Just embrace it and take it for what it is. And that is what many people did. Star Wars actually used some Nikkors in it’s production and the humble 43-86 is actually one of those Nikkors that were modified for cine use.

There are 3 major updates to this lens with the last one being a completely different lens that was redesigned from the ground up and for this reason, I will separate this article into 3 separate posts. The 2nd version (C) is a slightly modified version of this lens internally and is similar enough to this lens that you can work on it using this guide but I will make a separate blog post for it so that everybody can see the differences and appreciate the lens better in the engineering sense.

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:

This lens is a bit on the complicated side and I would not recommend this for beginners to fix as their first lens. The engineering that went into this the little lens was amazing, some of it’s parts work like a jigsaw puzzle and the precise alignments of the internal parts are also crucial for this lens to perform properly when you reassemble it. It actually took me several nights the first time I tried fixing one. I can now average 4 hours on one now since I am now familiar with this thing.

IMG_2065

The disassembly of this lens can be divided into 3 convenient parts:

  1. External parts
  2. Internal parts
  3. Objective (will not be discussed)

I apologise for not including the objective’s disassembly as I did not have any need to clean mine and the objective’s construction seems pretty straight-forward anyway. For those of you who are following my blog the disassembly of the objectives should be easy and it is in some ways similar to the Zoom-Nikkor 80-200mm F/4 Ai-S.

I would also like to advise you to take plenty of pictures and notes when working with this lens, specially before you remove anything that is a part of any precision assembly. Mark and measure if you have to because there is no way of knowing the tolerances and how the part comes off after the fact that you have already dismantled it. This is especially true for the internal parts that are involved in zooming so be careful! Getting this wrong will not only result in a lens that will not zoom in or out properly but it can also affect your image quality so you end up with a funky-focusing lens and all the people with the beard, chucks, sunglasses and plastic cameras will message you and give you an offer for the lens! I was just kidding, I did not mean to offend. I have facial hair, sunglasses and film cameras as well (but not quite plastic).

Disassembly (External Parts):

Dismantling the external parts is pretty easy and straight forward. You need to be careful with the helicoid, that’s all.

IMG_2066As with all lenses, always focus it all the way out to infinity and work with the lens in that configuration as your reference point. This pointer becomes more important with zooms because of their complicated engineering.

IMG_2067We start by removing this set screw and be sure not to lose it. This part is usually secured by paint or glue so be careful.

IMG_2072You can can also remove the front element assembly now and be careful about that brass ring under it as you do not want to lose or damage it.

IMG_2068Next, remove this screw to so that you can get rid of the focusing ring. This screw secures a small nut under it and it is responsible for keeping the push-pull pumping action aligned.

IMG_2070Carefully slide the focusing ring off from the the lens. This part is usually held by glue so place a drop of solvent or acetone into the seams in front of the lens or into the screw hole for the set screw. Mine took some effort to take off, I even used a rubber mallet to lightly tap it.

IMG_2073You can safely remove the helicoid from the rest of the lens at this point. Be sure to mark where it separates as well as the infinity point before you remove it as there is no going back after you have removed it!

You should not separate the helicoids while the focusing ring is still attached to it. If you did (like me) then it will require some guesswork to find out where and how it separated. This can be very frustrating even for the experienced. I am making the mistakes now for you to avoid later.

IMG_2075This is the nut that I am talking about. Be sure not to lose this little thing. When it is time to reassemble this back, be sure not to over-tighten the little screw that holds this or you will end up with a squeaky lens each time you pump it.

IMG_2077To remove the guide ring, you must remove these 2 rollers. Rotate the guide ring until you find them. Here is one near the minimum focusing distance.

IMG_2078And here is another one near the infinity mark. These can be a pain to remove since these were epoxied into place at the factory so be careful. You do not want to misplace or damage any of these since they are specially milled at the factory and finding a replacement part is impossible unless you salvage one from another lens.

IMG_2079You can now remove the guide ring from the rest of the lens. The rollers that you removed in the previous 2 steps were screwed to the holes inside the slot (see pic) and each time you push or pull the lens, it drives a cam inside the barrel and it moves the whole middle lens elements assembly up or down along a path.

IMG_2080We are now done with the front part so it is time to move on to the rear. Remove these five screws from the bayonet.

IMG_2082Carefully remove the bayonet from the rest of the lens. Be careful not to damage the brass shims, spring and other delicate parts found inside. Remember where these brass shims are placed, you should put it back in the correct order.

IMG_2083Before you can proceed, you should remove the aperture ring. Unscrew this M1.7 screw and keep it safe. Be careful not to cross-thread this part. This screw acts as a pin that connects to the aperture fork inside the barrel via a mechanism that you will soon see.

IMG_2084With the screw gone, gently unscrew the aperture ring from the lens. Again, be careful not to damage the threads as it is easy to cross-thread this part because the aluminium alloy is soft. I forgot the exact term but aluminium has a tendency to “fuse” when cross-threaded.

IMG_2087These brass shims are fragile and bend easily. Mine came in 2 separate pieces…

IMG_2085In most lenses the shiny metal grip is just a cosmetic part but on this lens it serves as the crucible where everything is connected to and is the most substantial part of the lens. It can easily make up 15-20% of the lens’ weight and is definitely milled from a single billet of aluminium alloy. You can use this to hurt somebody by smashing this into his forehead! Remove these screws to separate it.

IMG_2086Gently separate the outer barrel from the lens. I really like the useful ornate engravings on the focusing scale. I focus using the scale when I shoot and this is very handy for me as it shows plenty of apertures on the scale. The later models of this lens has fewer lines.

That’s it for the external parts. We are now going to start with the difficult part of the lens!

Disassembly (Internal Parts):

Now that we have gotten rid of the external parts, we are now free to move on to the inside of the lens where all of the action takes place. The internal parts are difficult because of all the precision alignments that you should take note of as well as the sheer amount of parts involved in it as you will soon see. Some of the parts are not easily accessible so you need to remove and reassemble each part in the correct order. This is Nikon’s first small-sized zoom lens and the engineers really gave a lot of effort designing this lens.

You will appreciate the effort even more after you realise that this lens was designed in the early 60’s (originally for the Nikkorex)! Show this to anybody who has a machine shop and he will tell you that the parts for this lens is difficult to mill and each is a work of art.

IMG_2088Remove the 2nd lens element assembly by using a lens spanner. These 2 holes should give you a hint on which tool to use.

IMG_2089Be careful not to damage the glass. Use a lens sucker to remove it. In my case, I got lazy so I just used my fingers to pull it out. There is a raised lip where I could hold on to anyway.

IMG_2090Remove the 3rd lens element assembly using a set of spanners again but this time around you definitely need to use a lens sucker because this part is situated deep inside the barrel.

IMG_2091And off it goes…that was easy isn’t it? we are just warming up!

IMG_2092Carefully remove this guide screw but before doing so, please take measurements and pics so that you will know how much this part should go into the slot later on when it is time to reassemble the lens. The barrel where it is connected is a small helicoid so you should do your best to document it’s position before you dismantle anything.

Pushing and pulling the lens will give you a hint on how far this moves within the slot and it will also show you how the other mechanisms work. Be sure to work on this lens while it is focused all the way out to infinity.

IMG_2093Remove these 3 screws to separate the black plate where the aperture fork and stop-down lever are both attached to. Be sure not to foul-up the bearings or you will have to overhaul that as well and it is never fun to repack bearings!

IMG_2094OK, time to remove the plate but oops! The plate will not separate because the post for the spring is obstructing it.

IMG_2095Carefully remove and store the spring and the post in a safe place. The post is delicate and you should only remove it with the proper tool. The closest thing I have at the moment is a 0.9mm screwdriver so I inserted the tip into the hole and slowly twist it counter-clockwise until the post is free. It is very easy to damage to the threads on this part so be careful.

IMG_2097Next, remove the 2 screws that you will see inside this slot. These 2 screws secure a small metal prong that has a slot in the middle. This slot is where the pin of the aperture ring rests so the alignment of this part is important. Adjusting this part left or right will cause offsets for the iris opening, making it bigger or smaller than spec. It is best to mark where this part should rest take pictures of it before you remove it so that you have a reference of it’s tolerances. I simply scrape it with the tip of a screw driver so all I need to do later when it’s time to reassemble it is simply to align the scratches that I had made before.

There is a way to remove the plate without going through this step but you will need a lot of patience because you will have to rotate the plate until this prong aligns with the hole in the huge aluminium grip and that will allow the prong to slip out. I do not want to bother with that and I am doing a thorough overhaul anyway so I simply opted to remove this.

IMG_2099Finally, with all the obstructions gone, you can pull that plate containing the aperture fork and aperture stop-down fork away! Feels good doesn’t it? Now is the time to document or take more pictures of that helicoid before you dismantle it. This is a very tricky part so pay attention to how things are connected and by how much (tolerances).

IMG_2101Next, remove these screws to free the shiny aluminium grip from the rest of the lens. Note that A and B are not not the same as one is wider than the other. This is important to note later on when you reassemble the lens so that you know which post goes where. These are screwed to 2 pillars underneath it. The pillars are part of the basket that holds the middle lens elements assembly.

IMG_2102Simply remove the aluminium grip from the rest of the lens barrel after removing the four screws.

IMG_2103Highlighted in this picture is the slot where that big guide screw should reside. We got rid of that a couple of steps before. Also notice the fine scratches that I made to mark where the  guide screw should be when the lens is collapsed to it’s minimum length.

IMG_2106The basket can now be removed from the cup. Also mark one of the holes where one of the pillars go through so that you know which holes these pillars should slide through, if you got it wrong then you will spend a lot of time later in reassembly. Also note that the ridge of the basket’s rim is lubricated. This means that you will need to lubricate this part later.

The cup is a single piece of aluminium alloy, just think about how difficult that was to mill.

IMG_2107Examine the bottom of the cup and take notes before you proceed. Next, remove the rear lens elements assembly by using a lens spanner.

IMG_2108Be careful not to drop the rear lens elements assembly as it is a bit heavy. Note the scratch that I made on the bottom lip of the cup. I use it as a reminder as to where that screw hole should be when I reassemble the lens. Make as many marks as you need so long as it will make sense to you later on.

IMG_2110To separate the rear helicoids, simply twist the iris assembly until it separates. Again, get a sharp tool and mark where they separate. This part is going to be the most difficult in the whole lens because you need to get this right or else you will get a soft-focusing lens that is only good as a paper weight. My technique for this part was to rotate the brass helicoid until it’s limit and then I simply twist this thing off from inside the cup after taking some pictures and measurements. This ensures that the brass rear helicoid is not moving at all and my reference point is not rotating.

IMG_2112With the iris assembly and it’s helicoid gone, you can now twist the rear brass helicoid off and be sure to mark where it separates. If you examine the picture above you can see that I scribed an arrow and a line on both surfaces to remind me where these things should mate later on. I can tell you from experience that even if you took adequate notes and pictures, this part is going to be frustrating to reassemble so never underestimate this.

IMG_2113Just take a look at that caked and dried up grease, yuck! Again, some scratches made by me so that I know how these things should align later.

IMG_2114Locate this tiny screw and remove it…

IMG_2116With the screw gone, you can now separate the helicoid from the iris assembly. Be careful not to put too much grease into this part later as you can see, the grease can easily migrate to the iris blades and you will end up with an oily aperture problem several months later.

From The Readers:

Mister Hugh says:

“The newest version came to me as an Ai lens, with a factory aperture/diaphragm ring, and it has had one of Bjørn’s U-type metering chips/pcbs added by myself.  This was a very straightforward enhancement as this version of the lens has an older thin walled bayonet mount and fortunately its diaphragm spring is attached to the aperture lever well away from where the contact block is situated.  Its Serial No. is 963237.  Either of Bjørn’s U-type pcbs (that fits into a long contact block), or one of his I-type pcbs (that utilises the short 5-pin block) can be easily fitted to this lens.  (The L-type pcb might possibly be fitted with a large amount of bending and contortion to the print – however my present skill level is certainly not up to using the L-type print in this way on this lens.)

The other lens is much older and is similar to yours; it was non-Ai when it left the factory.  It has been very roughly Ai converted by a previous owner and the diaphragm spring is anchored right in the middle of the area where the contact block for a metering chip would be placed.  So for older versions that are to be cpu enhanced, this spring must be re positioned to clear way for the contacts – similar to how the late models of the 43-86mm lenses are done and it looks very easy to do space-wise.  Once this re-positioning of the spring is done, it will be just as easy to “chip” as the Ai version. The serial no for my old version of the lens is 478237, and is similar internally to the one that you have worked on Richard (Serial No. 479154).  Its aperture/diaphragm ring is also one of the very early screw on types, as is yours is I see.”

Conclusion:

This lens actually took me a lot of time to dismantle and put back together the first time I opened up one of these because I do not know where and how things should separate that is why I hope that you will learn from my mistakes here.

IMG_2118The picture above shows some of the lens’s parts after thorough cleaning. The parts are all well-milled considering that this is a budget lens aimed at the entry-level market.

IMG_2119The lens elements assemblies. Mine are clean anyway so there was no need to open them up. They are simple to open up if ever you need to clean yours. Just read up on my previous blog posts and see how I opened up and cleaned the other lenses to give you ideas on how to open these up.

The only stressful part of this lens is the helicoid for the rear elements assembly because it is so complicated and inaccessible. The later versions of this lens will simplify and correct this so stay tuned to see how it was made in the later versions of this lens.

Focus adjustments for this lens is done by rotating the focusing helicoid in and out until you get your infinity focusing right. Do this before you attach the outer focusing ring back to the rest of the lens. This is typical of many Zoom-Nikkors from the first one (this) to the ones made in the 1980’s so bear that in mind.

Also, be very careful about applying grease on this lens as applying too much will cause the grease to migrate into the optics and iris. Some of the inner parts do not need any grease at all. What I do is I just scrub the surfaces that come in contact with each other with my brush and I do not even dip the brush into the grease so I end up with an extremely thin coat of grease. That much is enough.

I hope that you enjoyed reading this post and please anticipate for the 2nd and 3rd part of this series. I will strive to write them in the coming month. Thank you very much, 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 paypal.com account (richardHaw888@gmail.com). 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.

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5 Comments (+add yours?)

  1. Trackback: Internet Nikon Repair Resources – My Take on Photography and Diving (Underwater Photography Mostly)
  2. Trackback: Repair: Zoom-Nikkor 43-86mm f/3.5 (2/3) | Richard Haw's Classic Nikkor Maintenance Site
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  4. Trackback: Repair: Zoom-Nikkor 43-86mm f/3.5 Ai (3/3) | Richard Haw's Classic Nikkor Maintenance Site
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