80-400mm AF-VR ED 4.5-5.6 zoom lockup advisory. Read if you have this lens.

You might have seen my recent comments in an older thread regarding this kind of lens, which was broken.

I've invested some considerable amount of time and effort into getting two of these lenses repaired. I ended up buying two of them
and it looks like I will at least be able to get one working.

In fact I've been attempting to reassemble the lens and finish the job for two days now.

But every time I've got it together and I test the zoom, it has repeatedly and consistently locked up the zoom ring
after running it out to the short end (80mm) of the scale.

After having this happen a number of times I started to pay close attention to all the little details of the construction of the lens,
using the parts for the second lens to gain deeper understanding of how it works and what fails.

I have reached the conclusion that this is a design flaw in the lens.

I predict that eventually, due to wear and tear, every lens of this type will eventually lock up at the 80mm end of the zoom range.

I've found multiple postings online about this happening to other people.

The cause of the zoom lockup relates to the way that the zoom system is constructed. I'll explain first, and try to get some
clear photos to go along with it, later.

The primary components of interest are the zoom system shell, which is a cylinder with spiral grooves (3 of them) in its outer surface.
and a ring assembly that has rollers that ride in those grooves as the ring and attached parts go up and down relative to the shell.

The problematic part is that ring assembly. It consists of two rings, closely spaced, which are held apart by short springs. Each of the two rings carries a set of rollers on it, that run in the groove in the zoom shell. One ring's rollers ride against the "left side" of the grooves, adn the other ring's rollers ride against the "right side" of the grooves. The spring tension between the two rings
gives the zoom system a smooth feel with no rattle and with consistent tension.

What happens is, when the lens ages and parts wear, as you reach the short end of zoom travel. the upper of these two rings can travel too far up and partly OFF the zoom spiral. When this happens, the spring tension forces the rings farther apart and at this point, the zoom is locked because now the rollers are too far apart to be able to be easily slid back into the spiral grooves.
Additionally, there are interlocking bosses in the two rings so that they can't twist relative to each other. When one ring partially
leaves the spiral, and you try to force it back, these interlocking features can get jammed up and the rings can even get tilted or
cocked slightly relative to each other. If this happens, the zoom might be functional but it's going to be stiff, draggy, and will start shaving metal shavings and distributing them in the lens almost immediately.

I'm looking at two fixes for this problem. One is to slightly restrict the travel of the zoom ring in the barrel assembly, so it can't reach the full 80mm end of its range. I'm also looking at a modification of the two rings that will keep them from being able to spread
too far apart.

If you have one of these lenses, and you're having no issues with it as of yet, I would recommend that you try very carefully to avoid running it down to the stop at the 80mm end of the range. If you never get close to this end of the zoom ring's travel, the problem
as described simply can not occur.

There is no problem with the long end of the zoom range. Run it out to 400 with wild abandon, the problem can NOT occur out there.

All Nikon had to do in order to keep this from happening is to design the lens so that those two rings never get very close to the top end of the zoom barrel. Another 1/16th of an inch would have been sufficient.

I have this lens, and thankfully I haven't had any issues with it! But I will be careful with it as it gets closer to 80mm! Thanks for the heads up my friend!

I'm working on a preventative fix right now which can be done in a few minutes without any major lens diassembly. I predict it will work but I'll know for sure later this evening.

You need a piece of shim stock about a quarter inch square and about 1/32" thick. Metal or plastic.

Carefully pull off the zoom rubber grip and then remove the black plastic band under it, which is just taped on. Carefully pull the tape off the sliding contact and carefully remove the sliding contact. Remove the two screws visible in the zoom ring. Now rotate the ring to the 135 position and CAREFULLY pull it off. You will find that there are two copper spring plates (two pairs, actually) on the back side that you will have to reinstall later.

Now insert a fitted, snug fitting plug (the 1/4" square piece I mentioned) into the slot where the metal piece is that has two screw holes in it. (You just removed those screws to get the ring off.)

Put that filler piece at one end of the ring so that it restricts zoom travel at the short end. Reassembly is the reverse of the process. Getting the metal tab to slide to where you need it won't be difficult. You'll figure it out.

Those copper springs can be reinstalled through the longer portion of the slot where the contact fingers came from. Rotate it around, you'll see where they go in their own little recesses.

You can also slide those springs in from the inside of the ring as you slip the ring back on, but that is harder to do and get everything properly aligned.

The ring has to be oriented to about the 135 position to be pushed into its proper place.

Follow-up: Yes, restricting the zoom range as described above was successful. No more lock-ups!

I estimate the new zoom range to be around 88 to 90 at the low end.

The lens repair has been completed, as far as I'm able to at this time. For some reason there's an as yet undiagnosed short in the VR system. I have tried both VR lens assemblies and replaced the other circuitry in the lens as well, except for the CPU flex circuit, of which I only have one that is usable.

The short is severe, so bad that it will kill the battery in seconds. (Battery cuts out on current overload, for safety reasons.) But it's only present when the VR circuit is turned on.

That's OK, because this lens will probably be on a tripod pretty much 100 percent of the time and VR isn't necessary. It doesn't focus fast enough to be a good lens at the racetrack anyway but it should be killer for wildlife photography.

Considering the thing was broken in HALF when I got it, I'll call this repair adequately successful. For safety reasons I think I'll just disconnect the VR switch and be done with it.

Can anyone who has this model of lens with a Nikon hood on it please tell me the part number for the hood?

It's HB-24 !

D200freak said:

Can anyone who has this model of lens with a Nikon hood on it please tell me the part number for the hood?

Click to expand...

Thank you. I've now had some time to play with this lens and although the autofocus is really the slowest AF I've yet experienced, it does focus very sharply indeed. The sharpness of the images is commendable.

Saturday I receive my next lens repair project: A Nikkor AF-S 14-24mm G ED that needs some repairs. New lens hood, a few (presumably) sheared screws. All stuff that I can order up immediately.

The glass is all in great shape so I expect that to be a successful project. Best of all, no damage to the electronics.

That is the lenses I am getting later with our tax returns! Congrats on your new toy my friend!

D200freak said:

Thank you. I've now had some time to play with this lens and although the autofocus is really the slowest AF I've yet experienced, it does focus very sharply indeed. The sharpness of the images is commendable.

Saturday I receive my next lens repair project: A Nikkor AF-S 14-24mm G ED that needs some repairs. New lens hood, a few (presumably) sheared screws. All stuff that I can order up immediately.

The glass is all in great shape so I expect that to be a successful project. Best of all, no damage to the electronics.

Click to expand...

The 14-24mm lens arrived today, actually. To my pleasure.

Yeah, it has some "issues" but nothing I can't handle. I think the worst of the damage done to it
was done by someone else who "attempted" to fix it. Some people just aren't careful and can't be bothered to track down the repair manual before diving into something. The ribbon cable to the lens connector is torn in half. I can fix that. But there's no need for that to happen because the lens wasn't
damaged in such a way that that would have happened.

I've already ordered every part required to rebuild this lens. First task was to reassemble the aperture assembly correctly. Which took quite a few tries as it's VERY delicate work. But that's done. Hooray, that doesn't need any parts.

After the dust settles, I'll still have gotten a fairly good deal on this lens but it won't be a remarkably low total price. It'll still be under a thousand but not by an awful lot.

This thread is useless.
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Without images.



I'll play first. I gave my then 3 years old daughter a D40 + 18-55 back in 2012. She loves the camera, but as expected at some point last year (2014) she dropped it on the ground lens first. The end result: zoom ring jammed immobile.





I took the lens apart.





The culprit was two small triangle shaped bits of plastic at the inner barrel (between the yellow tweezers below). The pieces had broken off and got stuck somewhere in the helicoid.





I glued the pieces back to place, buffed the parts to high gloss, strengthened the weak parts with epoxy and put the lens back together. I also cleaned some small specs of internal dust. It's better (and stronger) than new.





And here we are on our outing by the sea last summer (2015), happy as a clam.

I can strip any camera or lens,no problem,just need someone to put them back together

I'll post some pics later today. I have plenty to post as I photo documented the disassembly process, screw by stinking screw.

nodevice.com has many Nikon lens service manuals available. I've bought five manuals and parts lists and gotten what I expected to get in each instance. They're reliable.

On the 14-24 lens, the primary problem with it is that the outer main tube has been badly buggered by someone else who attempted to "repair" it by dremelling out the broken screws that sheared off when the lens was originallly dropped. Those screws are part of the focus assembly.

It also has a cut flex circuit, and I couldn't get a matching replacement for it but I have ordered the equivalent circuit for a 24-70mm lens which is the same circuit only the flex is longer and it has a different overall shape to it. But contact for contact, the layout is the same so it should be usable.

The start of disassembly. Note the messed up iris. That was taken apart and correctly reassembled but it took several tries. Trying to reassemble a nine blade aperture correctly and have it all hold together in the right way while reassembling the system is kind of like attempting to herd cats with firecrackers.

The rear lens assembly was loose, just rattling around in the lens body when it arrived. I found two of the three screws that hold it in, in the lens body, loose. Had to order a third.

The damage pattern on this lens is interesting. No glass damage, a chip out of the integral hood, and a little impact dent/scrape near the camera mount. I think it fell and hit on the hood and hit in the back on the bounce.

Here we have photos of the torn flex circuit (which I could repair, but I will attempt to substitute one frmo a different model that appears to have the correct wiring even if it's longer and shaped differently) and also photos of the inner cam tube, clearly showing where somebody ELSE boogered the threads trying to get the stubs of sheared-off screws out. That individual is a HACK. He should avoid ever working on lenses.

The correct approach is to take such a piece to a good machine shop and have a good machinist mill off the top of the broken screw shaft and then center drill the screw shaft and drill through it, which will most likely drive the screw shaft cleanly out the hole without doing any thread damage. It's a job I could have
done myself, as I'm a machinist myself. (Amateur, but good enough for this.)

I have a new cam tube coming to me in about a week, along with every other part I need to restore this lens to good working order.

But I will still attempt to repair this cam tube anyway. It'll probably end up getting redrilled, tapped, and have Helicoil inserts put into it. If they can be properly centered up.

As soon as I have this 14-24mm lens fixed, I'll have the whole range from 14mm to 600mm covered in four lenses. That will be my travel kit.

Although there is, to the best of my knowledge, no online discussion group for amateur camera lens repairmen, it would be nice to be able to exchange information with others who also like to do this, so that by sharing information lens repairs might be easier.

For example, it appears that the aperture assembly for the 14-24mm F/2.8 lens is the same aperture assembly used in the less expensive 18-200mm VR lens. By the photos they're identical.

It would be very convenient to have a cross reference guide that tells me what lenses share the same parts. Finding out that something like a cheap, readily available 18-55VR lens has the same parts that are incorporated into a much more expensive lens, that needs those parts for repair, would be really useful.

Very informative. I just posted my questions concerning my desire to repair my 55-200 mm kit lens. I posted the picture of the piece that was sheared when I fell with my camera. I will check out your source for parts. I did follow the repair manual I found on line. I'm not a machinist; just a retired English teacher who is just to stubborn to go buy a new lens. (I think there might be a touch of obsessive personality, too.


Sent from my iPad using Tapatalk

You saw that I replied to your request, obviously. Repairing your lens will be a fun little project for you.

Buy a good microfiber cloth. It's easy to keep the internal optics clean and dust free if you use a microfiber as needed during the reassembly process.


Now as for that 14-24mm lens I was working on...I was right, the flexible circuit from a 24-70mm lens (the "GOOD ONE") is fully compatible. I just had to trim off some excess material that wasn't even part of the circuit.

The lens is fixed. It works properly. The zoom is SLIGHTLY stiff but that isn't a concern for me. In fact, I like the fact that it doesn't "gravity zoom" when letting the camera hang from the strap, lens down. Although the zoom is stiff, it's smooth, which is more important.