Juanjo Viagran
, Jan 17, 2007; 06:21 p.m.
Hi..
I already open one of my lens to clean some fungus but now I have another one
that badly needs a cleaning but can't unscrew the front glass. I called Nikon to
ask for what tool they use and they told me that I shouldn't open a lens because
they need a very pricise calibration that can only be done by them.
OK. I did it once with a AF ZOOM lens and the lens works no problem and the only
tool that I used was a screw driver.
OK.. I have two questions about this:
1- you know what tool I need to unscrew the front ring to take the front glass out.
2- I got lucky the first time I cleaned a lens? anyone here also open there lens
to clean it and if so can I get some tips.!
Thanks for the inputs
Juanjo
Juanjo Viagran
, Jan 17, 2007; 06:26 p.m.
by the way, the lens in question is a Nikon 180mm 2.8 AI and I'm going to also open a Nikon 300mm 4.5 AI as well.
Thanks
Michael Axel
, Jan 17, 2007; 07:01 p.m.
1) I don't have my 180mm in front of me, but will it take a spanner wrench?
2) I've read on these forums that fungus can spread to other lenses and equipment, but you might want to find out for yourself.
3) I've got a good friend that used to work for Nikon (corporate) and has a whole series of special jigs and tools to take apart lenses and put them back together again properly. Yet I hear of people doing this on their own and cringe because there's just no way you'll get them back together the way that a Nikon repair station would.
Conrad Hoffman , Jan 17, 2007; 09:18 p.m.
Most Nikon lenses can have the groups removed intact. Reaching for a spanner wrench first is almost always a mistake and the sign of an amateur lens butcher. Fungus usually happens on the accessible inside surfaces of the groups, not between the individual lens elements. It's usually not a big deal to get the groups reinstalled without compromising performance. That isn't the case if you remove individual elements. They all come apart differently, but many let you remove the rear group by removing the mount for access to additional screws. Others can have the front group removed by unscrewing a ring, but you really need a diagram from someone who's done it before. I don't have any experience with the focal lengths you mention.
Christiaan Phleger - Honolulu , Jan 18, 2007; 03:56 a.m.
Aiii! If its a 180mm Ai with a thick 'square' chrome ring, or a 180 Ai with more of a Ais ED
180 makes a Huge difference. The older thick 'square' chrome ring P 180mm Ai is a very
very tough lens to do work on. This lens is an overbuilt tank, with Tons of precise set
screws, a very very hard lens to get to the fungus to clean it.
Sure, you say, since you did an AF Zoom and that was easy (don't say which one, some are
easy and some are hard) but let me tell you, you haven't seen anything like the internals of
a thick 'square' chrome ring P 180mm Ai. If its like the later Ais ED with the smaller
thinner 'round' chrome ring it *may* be a bit easier, that particular subtle 'cosmetic' lens
change Pre-ED Nikkor is one lens I haven't done, but I've done an Ais ED as well as 2 thick
chrome ring P lenses and one was so difficult it became the parts lens for the other one,
which was only slightly (and I mean slightly) easier to work on. Probably due to the
learning I did on the first one and the second one was so photojournalist worn-out the
screws were loose (er).
If your lens is in decent shape execpt for the fungus, send it to the oldest Nikon shop
around, there may still be somebody alive that knows the tricks to working on it. If not,
either you live with the fungus and deal with that or run the 90+% chance of ruining
(DEstroying) the lens by attempting to fix it.
If you decide to attempt, contact me and if its one of those, (and your really really want to
try it) I'll see if I dig up the old carcass to help to get started. It will be tough, this lens is
about 9.2 on a scale of 10 in terms of repair.
Bob Bernardo - LA area. 
, Jan 18, 2007; 04:37 a.m.
The front lens element should just pop off using a spanner, as others have said. If it isn't too tight just a jewelers screwdriver will work. If you have to go deeper into the disassembly, Nikon is right that you need to realign the lenses. Again, the front lens just pops in place on just about all of their models, so no adjustment is needed.
Bob Bernardo - LA area. 
, Jan 18, 2007; 04:44 a.m.
Forgot about the 180 square ring. Could be trouble. There are set screws under the outter ring, 3 if I remember. Send an email to Christiaan. I haven't repaired one in over 10 years. It's a good lens to fix.
Juanjo Viagran
, Jan 18, 2007; 09:50 a.m.
Ron Ries , Jan 18, 2007; 01:08 p.m.
Juanjo Viagran
, Jan 18, 2007; 05:31 p.m.
Thanks for the rubber tool idea...
I called them and they have all the sizes but mine (72mm)
Any idea of any other place I could get that tool..?
I did some google search but no luck.
Thanks.