Fixing a Nikkor 105mm f/2.5

[Thomas G]

approaching the next step which developed the potential for headaches and twisting muscles and brain.
the little offender is the spring which, by design, pulls back the diaphragm when fitted properly.

[Thomas G]

1 which proved to be an undertaking. taking long.
2 finally my beloved and uncomplaning wife helped to add hands.

[Thomas G]

we reached the 'give me five' status, at the same time realizing that we missed to place the following:

[Thomas G]

unfortunately these belong inside. what a disapointment.

at about 8:30pm I started to dismantle the lens again, making room for placing the forgotten parts.
then fitting the little spring again.

back to working state it still looks like having had a rough life, now working like a charm again:

[Thomas G]

Summary:
The lens works better than my other example, I still feel it's a bit stiff in dianling the distance.
John and other shared that this is the 'right' drag for this generation of lenses.
Time will tell if I'm going to peplace the grease again.



Thoughts:
- get different types of grease
- make a more descriptive sequence of photos of the individual steps (next time)
- keep the little parts jars in the right sequence (for sure)
- learn how to take the helicoil apart (there seems to be a trick I do not know yet)

[Edgy01]

Wonderful write-up!  You are a very brave (and talented) soul.

Thanks for sharing.  Some day when I find a few quiet hours I need to take apart a very early 50mm f/2 Nikkor that has an aperture ring that takes muscle to turn (but only in one direction--the other is quite strain-free).

Dan
Santa Barbara, CA

[the solitaire]

Summary:
The lens works better than my other example, I still feel it's a bit stiff in dianling the distance.
John and other shared that this is the 'right' drag for this generation of lenses.
Time will tell if I'm going to peplace the grease again.



Thoughts:
- get different types of grease
- make a more descriptive sequence of photos of the individual steps (next time)
- keep the little parts jars in the right sequence (for sure)
- learn how to take the helicoil apart (there seems to be a trick I do not know yet)

The trick for taking apart the helicoid is to remove the plastic collar on which th edistance scale is engraved along with the silver mounting ring, then turn the helicoid far enough that the helicoid key shows up in the groove on the side which is revealed by removing the collar.

There is one location where next to the groove you can see two approx. 3mm round holes. The key needs to align there. Remove the 2 screws that hold the key by sticking a screwdriver through said holes and applying it to the screws in the only way that makes sense when you see those things.

Mark where the helicoid is when the key is visible and mark which way is up for the key. Then unscrew the helicoid, use a marker to mark wher ethe helicoid parts because it is a multi lead thread.