Nikkor 180 f2.8 focus ring is very stiff

[dallypost]

I have a Nikkor 180, f2.8 that has not been used in years. Now that I am shooting micro four thirds, I thought that it might be fun to have the equivalent of a 360 2.8. Trouble is that the focus ring is really really stiff. I suspect that the helical just needs to be cleaned and re-lubed. I have not been able to find any info about how to tear the lens down. I really don't want to dig in until I have some understanding or what I should be doing. Your help will be appreciated.

Lance

[Lloydy]

Sometimes warming the lens and working it will loosen the lens by moving the stiff grease. I have warmed a lens by putting it on a radiator for a while then sat watching TV and just winding the focus in and out. It's 100% guaranteed to drive my wife mad, but I ignore that. Sometimes it works and is a permanent fix, other times its temporary. I have a Yashica 135 that I warm up before I take it out, it's just enough to loosen stiff grease.
Some people might suggest pouring Zippo lighter fluid into the lens, it works for about 2 minutes then evaporates and the grease goes stiff again. But not before it's washed oily residue over the glass and blades. Resist using lighter fluid. The only real cure is to dismantle and clean the crappy grease out and replace it, but try warming and moving it - that costs nothing and does no harm at all.

[WNG555]

What's a recommended lube for the lens internals? I am assuming it needs to be a very low viscosity grease, like a moly based lube.

I also have a very stiff lens, a Tokina AT-X 80-200 f/2.8 zoom. I've taken it apart partially to remove fungus, will try to go further.

[dallypost]

I have a tube if white lithium (I think) grease. I have used it on lenses in the past and it seems to hold up for years. My question is, how do I take this lens apart. It is a nice enough lens that I don't want to ruin it. Just forward of the aperture ring and just behind the depth of field scale is a large silver knurled ring. It looks like a big step up ring as it increases the diameter of the lens about a half in on all sides. On the back of this ring are three phillips head screws. I am thinking that if I remove these screws, I can separate the two halves of the lens and access the helical. Can anyone confirm this?

You can see a picture of an identical lens here http://www.ebay.com/itm/like/110906823784?lpid=82&chn=ps

Thanks

[luisalegria]

I must speak up for my favorite substance, lighter fluid (perhaps I have inhaled too much of it).
It has worked for me quite reliably in these cases.
A few drops carefully applied can work wonders.
Not usually a perfect fix, but 9 times out of 10 it makes the unusable usable, at least.
It should be applied very sparingly directly to the helical thread.
In the case of the Nikkor the lens mount plate will have to be removed to access this thread.
A couple of small drops, then work the focus back and forth to get it seeping through the length of the thread. It will loosen it up like magic. When it dries up the mechanism will tighten up again, but hopefully in a much better state than before. Its much better to do a full disassembly, clean out the old grease and re-grease, but this is often a challenging procedure.
Done carefully it should have no opportunity to get into the glass and aperture mechanism.

[sceptic]

If you're going to apply some solvent into the threads, I'd suggest using WD-40 or similar (just a drop or two). It will also dissolve the hard grease but, unlike zippo fuel, it will not evaporate but rather mix with the grease and stay there. I have done this with lenses that I have regreased and found to be too stift even with the fresh grease.

FWIW, all Nikkor lenses I've regreased have been dismantled by first taking the mount off.

[aoleg]

Okay, here's my advice. No lithium grease. No lighter fluid. And absolutely no WD-40. I don't know why these keep popping up, but these are disastrous (especially the WD-40 stuff, which has potential to ruin your entire lens).

Use medium-heavy, synthetic, silicon grease with no color and no smell (if it smells, there is a chance it'll evaporate and ruin your lens). Disassemble the helicoid and clean old grease before applying new one. Choose grease with maximum temperature range (-50 to +175C is pretty standard for silicone greases). Absolutely avoid any petroleum-based greases; they will eventually separate, the light fraction evaporate and ruin your lens.

Hope this helps.

P.S. I had to fix too many lenses "repaired" by individuals who used lithium grease. Please. Please. Don't use this stuff in lenses. It's not intended for this purpose.

[sceptic]

One can't rule out lithium grease as a group, since there are hundreds of different lithium greases available. Helimax XP, for instance, is a lithium grease specifically designed for focusing helicals (and it works great, by the way).

[luisalegria]

9/10 of owners of old lenses are not likely to be able to disassemble the helical to do a proper re-grease.
Or if they do they are not likely to be able to put them back together properly.

This sort of thing is easy for some people, very difficult for others.

[luisalegria]

And FWIW, Nikkor lens mounts, which you have to be able to remove in order to do anything, are often quite difficult to remove as the screws are usually in there very tight indeed, and they use the Japanese style cross-head screws that looks like Phillips but aren't. Do not use Phillips screwdrivers, these will just damage the screw unless its in fairly loose (we are rarely that lucky). If they are at all tight do not even try to exert force with a Phillips screwdriver.

You need the proper screwdrivers (have to buy fro Micro-tools) or if you really have to a flat-blade small screwdriver is second-best, if the blade goes all the way across the slots. Loosen the screws first with -

- Put a screwdriver on the screw head (flat blade that fits) and tap fairly hard with a hammer to loosen the thread
- Heat the screw head up (to where its too hot to touch) with a soldering iron, and let it cool.
- Use a small drop of WD40 brushed on the screw heads and left on overnight.

May have to do all three.

This is just step 1 in disassembling the lens, and it just gets harder from there.

[dallypost]

What do you mean by FWIW?. For everyone’s information, I am going to do this repair correctly or I will not do it at all. I have no interest in secret potions and temporary fixes. The white grease I have I used to fix a 55 Nikkor macro lens some 25 years ago and it is still going strong so I will stay with that grease. To separate the helical, do I go after it from the front of the lens or do I remove the aperture assembly and go in that way? I also have a question about reassembling the helical once it is disassembled. I have read horror stories about people who can't seem to get the threading started correctly and can therefore never get proper focus. Is there a trick. I was a Air Force flight engineer so I am pretty handy and like to do things right.

I would love more advice but would really like to focus on fixing, not hacking this lens. Thanks all.

Lance

[luisalegria]

FWIW - for what its worth
No stress, not wanting to get into fights on this.
Just that not everyone is up to this sort of strip down.
Done it both ways (or many more than that) on dozens of lenses, shutters, etc.
Theres the right way, the wrong way, and whatever works. No airplanes are going to fall from cutting corners on fixing a cheap lens.

Each lens is different as far as approach to stripdown.
Never worked on a 180, just 135, 105, 50
A new one is always an adventure.

Usual case with Nikkors is to go in from the back and remove the mount, aperture ring, rear optical block, etc. to give (mostly) unimpeded access to the female side of the helical. This is a shortcut as you will not reach the end of the threads doing this but odds are you will get most of it. Use whatever solvent works on q-tips to get rid of old grease, working the helical will get more old grease in a place to clean it off.. You will not get all the old grease, quite, but certainly most of it. If its turned to glue you will not get too far doing this as you wont be able to use a wire brush or dremel wheel to remove it.

Best probably also to remove the front optical block and the tube with the aperture mechanism. That involves removing either or both the front end tube or the name ring. At least this prevents damage while working on the mechanics. Often the whole optical block is a unit with the aperture mechanism and it will come off as a piece. The Takumars are often like this.

There is usually a stop screw that keeps the helical from unscrewing completely. IIRC this may be revealed if the focus sleeve is removed. People like to hide the screws for this under the rubber grip.

If you do plan of completely disassembling the helical, the only trick is to mark the exact point (on both parts) at which the screw disengages. You can only do this once, so get it right. Best to scribe the mark.

[sceptic]

Thread locker (of which Nikkor lenses have plenty) can be softened/dissolved with acetone. In Nikkor lenses, you will find two kinds; white glue in the threads and (sometimes) a red "laquer" applied on top of screw heads.

Before separating two helicals, mark the position they are in before you start ("original state"). This is as important as marking the point at which they separate.

The separation point is important for knowing how to align them for reassembly. Knowing the "original state" is important fir knowing when to stop turning.

[Lloydy]

I agree that WD40 is the work of the devil in a lens, yes - there is lube, but the solvents creep everywhere; especially when shot out of an aerosol can. It might work, but there is a risk of unwanted side effects.

Lighter fuel will dissolve the grease, but it will also creep and take some of the oils from the grease just like WD40, and it evaporates rapidly and the grease goes stiff again. This is my experience of trying it on a few lenses. If you want to soften the existing grease then a very light oil will be better, in very tiny quantities. grease is a soap that carries lubricating oils and when the oil separates from the soap the soap goes stiff, replacing the oil is a far more long lasting cure, but of course that relies on being able to mix the fresh oil into the soap, and where has the old oil gone?

Worse than WD40 is the molybdenum disulfate grease that some manufacturers used and is often recommended. MD grease is very effective as a lube' IF it is moved on a regular basis, if left for long periods the oils separate from the soap. I have done this by putting a spoonful of grease in a plastic cup and leaving it for a few weeks, there was a definite puddle of very thin oil that had run off the grease. It's a superb high temp' - high pressure grease which is why its used on vehicle constant velocity joints etc. But does a lens need that pressure and temp' range? I use general purpose grease such as is used in bicycle wheel spindles. People get enthusiastic about high performance greases, which are great for the high pressure and temp of a vehicle wheel hub, but are we subjecting a lens helicoid to thos kind of pressures and temperatures? If we do, the lube isn't going to save it.
I spent most of my working life as a maintenance engineer, hands on the spanners - not a desk engineer, and the drums of MD grease we kept in the workshop always had a puddle of oil in them, the other greases didn't.

Would I try lighter fuel? I have and I still do. Does it work? mmmmmmm......I think it's temporary.

[sceptic]

[Lloydy]