Nikkor 28mm f/2.8 AIS Service Difficulty

[chuckroast]

I have the aforementioned lens, but the helicoid could use cleaning in lubrication. It is both slightly looser than I like and seems to bind slightly at certain places in the rotation. The lens otherwise works fine and has decent optics.

How hard is it to tear down one of these? I will avoid DIY if I have have a collimator or an optical bench.

If I do take it apart, what is the recommended lubricant for the helicoid?

 

[F4U]

Lenses like this are not for the meek. Helicoids on these lenses have LOTS of starting points when you disassemble them. Not only that, but you are not unscrewing just one that you have to get started in the right starting groove, but there's 3 separate ones that must go back, starting in the same groove as you took it apart. that means you have to make 6 nicks in the metal. And making nicks takes skill. Make one too deep, or in the wrong place, an the lens will forever have a rough spot in focusing. Further, you mentioned it being AIS, which probably means rubber focusing grips. The screws are underneath the rubber, which is 50 years old. How are you going to get those dried-out rubber grips off without ruining them? I don't know. But I do know in all my years of taking gear apart and servicing of it there's NO WAY would I fool with one of the rubber-grip AI Nikkors. How often is anybody ever really going to use a 28mm? It's your lens, but I'd forget the whole idea. It's loose, yes. But it still works fine. This is one repair you need to send to an expert who knows what they're doing.

 

[chuckroast]

Lenses like this are not for the meek. Helicoids on these lenses have LOTS of starting points when you disassemble them. Not only that, but you are not unscrewing just one that you have to get started in the right starting groove, but there's 3 separate ones that must go back, starting in the same groove as you took it apart. that means you have to make 6 nicks in the metal. And making nicks takes skill. Make one too deep, or in the wrong place, an the lens will forever have a rough spot in focusing. Further, you mentioned it being AIS, which probably means rubber focusing grips. The screws are underneath the rubber, which is 50 years old. How are you going to get those dried-out rubber grips off without ruining them? I don't know. But I do know in all my years of taking gear apart and servicing of it there's NO WAY would I fool with one of the rubber-grip AI Nikkors. How often is anybody ever really going to use a 28mm? It's your lens, but I'd forget the whole idea. It's loose, yes. But it still works fine. This is one repair you need to send to an expert who knows what they're doing.

Kinda what I figured.

 

[F4U]

Remember. I may be wrong. But I have disassembled lenses before, just not this one. Nor would I.

 

[chuckroast]

Remember. I may be wrong. But I have disassembled lenses before, just not this one. Nor would I.

I have mostly worked on leaf shutters and simple adjustments to rangefinder lenses. This seems daunting to do, and the helicoid isn't THAT bad.

 

[David R Williams]

I've been very happy working on older Nikkors using Richard Haw's lens repair information, and also his very helpful guidance on "managing" helicoids during disassembly and reassembly.

He has a dedicated walkthrough for the 28/2.8 AI-s here, which is somewhat more complicated due to the lens including one of the first (if not the first) floating element CRC systems.

Repair: Nikkor 28mm f/2.8 Ai-S

Hello, everybody! I am currently not feeling well today because of hay fever or the cold. I hate Winter but it’s something that I need to put-up with every year. Good thing we’re using …

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...and this is his reference library that provides helicoid information and other related information that excellent background and helps get up to speed on lens repairs...

Repair Tools & Fundamentals

Lens & Camera Repair Fundamentals: These were made in order to show people what are the important tools and practices for repairing cameras and lenses. If you are new to this, I advise you read…

richardhaw.com

I hope this helps!

(My copy of the lens was needing work when I purchased it few years ago, but with some patience, the correct JIS screwdrivers (this is VERY important) and a few attempts with varying viscosities of synthetic grease, it now feels and operates beautifully.)

 

[4season]

I've had success servicing AI-S and older Nikkor lenses (I don't own anything newer, so I can't speak of those). That's a great tutorial by RH, but chances are, you won't need to do such a deep teardown or disturb critically aligned parts simply to clean and lubricate the focus helicoids, aperture ring, and perform a general cleaning.

 

[chuckroast]

I've had success servicing AI-S and older Nikkor lenses (I don't own anything newer, so I can't speak of those). That's a great tutorial by RH, but chances are, you won't need to do such a deep teardown or disturb critically aligned parts simply to clean and lubricate the focus helicoids, aperture ring, and perform a general cleaning.

Any guidance what minimal maintenance I could do (and how)?

 

[F4U]

If I may chime in with a question... how do you get the rubber focus grip off and back on without ruining it?

 

[4season]

If I may chime in with a question... how do you get the rubber focus grip off and back on without ruining it?

I simply slide those off by hand. I suppose there may come a day when they're too aged and brittle to withstand such handling, but I haven't had that problem to date. But if it happens, it happens, and I'll devise a replacement grip surface at such time.

 

[BrianShaw]

Hi Chuckroast. I’ve not overhauled many lenses but the few I have I’ve overhauled several times. The “proper” grease is a damping grease as that gives a smooth feel. Damping greases come in different grades based on the amount of damping they provide. I’ve not had luck with makeshift alternatives yet others seem to have. Getting the right feel, for me, has been a trial-and-error situation. Good luck on your project.

 

[chuckroast]

Hi Chuckroast. I’ve not overhauled many lenses but the few I have I’ve overhauled several times. The “proper” grease is a damping grease as that gives a smooth feel. Damping greases come in different grades based on the amount of damping they provide. I’ve not had luck with makeshift alternatives yet others seem to have. Getting the right feel, for me, has been a trial-and-error situation. Good luck on your project.

I guess my question is how much of a teardown is required to clean and re-grease

 

[Nicholas Lindan]

I use Corning High Vacuum Grease. It does not separate and throw oil, unlike the helical grease from Japan Hobby Tool. I inherited a jar of vacuum grease that dates to 1965 and there is no separation or oil present. I haven't tried Nye damping grease. The grease used by Nikon will throw oil, though I have only had problems on a few lenses.

 

[4season]

Any guidance what minimal maintenance I could do (and how)?

If the glass looks decently clean, and the diaphragm is dry and "snappy", perhaps just unscrew lens cells as complete units, and don't disassemble the diaphragm. Often, minor specks and haze are limited to the glass surfaces facing the diaphragm, and can be readily cleaned without disassembling the lens cells.

But the helicoids and aperture control ring ought to be serviced. De-gunking the former is kind of a messy job but easily tackled with old toothbrushes and solvent or ultrasonic cleaner, if you have one. Nikon's CRC involves an additional helicoid, and it can become so fouled that it barely moves, so you definitely want to service this. I have moderate experience, and generally think of servicing these vintage prime lenses as one-afternoon projects, much of the time being spent on trying to recall how the helicoid was supposed to go back together.

Servicing the aperture ring is super-simple, because all you're really doing is wiping away old lubricant and accumulated dust/grit, and (sparingly) applying fresh lubricant. Best of all, Nikon traditionally used a creased metal spring as the clicker, good for a jillion cycles and hard to lose because it's screwed into place. You will resent other brand's use of spring-loaded BBs once you've gotten a few Nikkors under your belt.

 

[BrianShaw]

I use Corning High Vacuum Grease. It does not separate and throw oil, unlike the helical grease from Japan Hobby Tool. I inherited a jar of vacuum grease that dates to 1965 and there is no separation or oil present. I haven't tried Nye damping grease. The grease used by Nikon will throw oil, though I have only had problems on a few lenses.

Learning the differences between greases is something that takes time and experience so thanks for sharing your experiences! I used the Nye products and they seem to be very high quality. When I most recently bought damping grease I intentionally steered away from "hooby supply sources" and unmarked containers. One related field of interest that shares a need for high-quality damping grease is telescopes, and their suppliers seem a reliable source of good product.

 

[250swb]

I have the aforementioned lens, but the helicoid could use cleaning in lubrication. It is both slightly looser than I like and seems to bind slightly at certain places in the rotation. The lens otherwise works fine and has decent optics.

How hard is it to tear down one of these? I will avoid DIY if I have have a collimator or an optical bench.

If I do take it apart, what is the recommended lubricant for the helicoid?

Binding on rotation is something Leica lenses often get sent to techies for and a hefty bill ensues. It's not something I've come across with Nikon lenses but with a Leica lens (and I guess many others) the fix is incredibly simple. Over the years the torque of mounting and dismounting the lens causes the mounting flange to twist a bit and the screws loosen, this then causes the barrel to bind as you focus. To fix it loosen all the flange screws and tighten them down again slowly going opposite to opposite (like you are tightening a car's cylinder head bolts). Hopefully it's not more complicated than that.

 

[ic-racer]

I have the aforementioned lens, but the helicoid could use cleaning in lubrication. It is both slightly looser than I like and seems to bind slightly at certain places in the rotation. The lens otherwise works fine and has decent optics.

How hard is it to tear down one of these? I will avoid DIY if I have have a collimator or an optical bench.

If I do take it apart, what is the recommended lubricant for the helicoid?

Nikkor lenses come apart quite easily. The optical group usually comes out together, leaving the focus helicoid. If you don't already have helicoid grease, you can get "Nikon" helicoid grease from Polar Bear camera.

I have an autocollimator, but in my experience, every un-molested Nikon body I tested had the focus screen at the 'correct' spot. So you may be able set infinity focus using your camera body.

The 'correct' focus screen placement is not at the distance to the out rails or distance to the inner rails, it is to the film surface.

Nikkor 24/2.8 Pre-AI: Fixing an Awful Squeal

I got this very nice Nikkor 24/2.8 Pre-Ai lens. Looks mint but...ouch it has a terrible squeal when focusing it. Sounds like it is coming from the back of the lens. Lets see what could be the problem....

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