A little technology

Repair is a profession...

It's also a passion

This page has only one purpose: to explain a repair procedure.

I decline all responsibility if you break your beautiful toys... That's it!

Lubrication of helical lens ramps

Basic method

This tutorial is based on a Nikkor 35mm f/2 AIs. This method can be applied to a large number of lenses from other brands, these are basic principles to remember.

Get the right tools!!!

1/ The wrong screwdriver and your lens may be totally damaged or even unremovable.
JIS (Japan Industrie Standard) screwdrivers are essential. ( see VESSEL )

2/ Be tidy, precise, careful and patient.

3/ Take photos at each stage of dismantling.

4/ Mark the marks before dismantling the ramps. 

5/ Use lubricants for photographic equipment.

6/ Use Zippo petrol to clean the ramps. 

7/ Use Isopropyl alcohol for the final degreasing. 

8/ Use acetone-free nail varnish remover. 

9/ Have toothpicks and cotton buds available.
 ( yes, toothpicks ) 

10/ Use any colour nail varnish you like!

11/ Line up the parts in front of you in the order in which they will be dismantled.

12/ The essentials…

Blower bulb,

rubber pad,

suction cup for lens,

soft brushes


liquid neoprene glue,


medium threadlocker,

ice cube tray (for example) for screws and small parts,

tweezers or tweezers (worst case scenario),

fine indelible markers

drawing clips,

and a host of other useful bits and bobs that will be added to your toolbox as you go along.

Let’s get started!

The front sections :

First thing to do, remove the rubber ring from the focus ring.

On the focus ring, there’s a small hole.
Inside is a tiny needle screw sealed with varnish.
Apply some nail varnish remover with a cotton bud and wait a few minutes.
Repeat the operation at least twice.
Using a very fine flathead screwdriver, unscrew the screw.

If you screw it up, the only solution is to drill with a metal bit of the same diameter.

Don’t worry, it happens,
(drilling is not without risk).

To enlarge, click on the image ( 2 photos )

When the needle screw is unscrewed…

( there’s no need to remove it or keep it carefully )
Use either special rubber pads,
or use gardening gloves, with a soft rubber part on the inside of your hand.
Unscrew the front ring of the focusing ring.
You need to do the same on the front ring of the lens.
You can dismantle the front ring and unscrew the optical unit.
This gives you access to the three screws that fix the focusing ring.

To enlarge, click on the image ( 4 photos )


Set the dot ring to infinity.

Remove the varnish with nail varnish remover on a cotton bud.
Use a very thin Phillips screwdriver.
Remove the fixing screws and brass ring.
Pull the ring forward and you will see the internal infinity mark.


Measure the positions of the infinity ramps.


Mark the positions for infinity on the front
the front chopper, the point and the barrel.

To enlarge, click on the image ( 5 photos )

The rear parts :
Removing the bayonet.

The three screws are tightly sealed with threadlocker.
Here again, use nail varnish remover and a cotton bud.
On this optic, the solvent was renewed 5 times
before the screws came in…
Be patient!

Dismantling the diaphragm drive ring.
Locate its position in the barrel and the aperture ring.
Remove the aperture ring.
Nikon’s advantage: there is never a spring-loaded ball to detent the ring.

To enlarge, click on the image ( 4 photos )

Let’s get on with it!

Spiral ramps


Until now, the ramps have been held in place by the guides.
Removing these guides releases the rotary movement of the ramps.


Unscrewing the ramps is a very delicate operation that requires
a great deal of precision!
Hold the barrel on a table, with the rings between your thumb and forefinger.
Turn the first ramp very slowly.
(The one that supports the front light unit).
Turn until the ramps separate, then be very careful,
you must mark a separation mark on the ramp
opposite the infinity mark.

To enlarge, click on the image ( 2 photos )

Remove the first ramp and move on to the second one
( the one for the point ring ).
The method is exactly the same.

Clean the old grease with Zippo petrol.
Final degreasing with isopropyl alcohol.
Even ultrasonic,
It should shine and be perfectly clean!

To enlarge, click on the image ( 1 photos )

Greasing of the dot ring ramp.

You need to fill the barrel with a brush, but there’s no need to stuff it full of grease.
When you screw it back in, the excess will get everywhere in the barrel,
This is wasted grease that will have to be cleaned up.

There are several densities of grease,
some for short and normal focal lengths,
others for telephoto lenses, and the mechanical constraints
are not the same.

I now only use Helimax, which requires some mastery of the product.
mastery of the product. This grease is, in my opinion
more universal. You need to use very little and the choice of dosage
will give a more or less firm movement to the choppers.

To enlarge, click on the image ( 1 photo )

For reassembly


Start with the focusing ring.
Position the ring flat on the barrel.
Turn in the opposite direction to screwing.
Listen carefully for the little ‘clicks’ and in particular,
the one that corresponds to the marks made when unscrewing.
This is when you need to screw in the right direction ‘’WITHOUT FORCE‘’.

If it doesn’t work the first time, be patient and start again !!!!
When it’s in place, do a few screwing and unscrewing operations to
to distribute the grease evenly, without going to the separating points
of course!!!

To enlarge, click on the image ( 1 photos )

Let’s not give up!

The final
Set this first ring to infinity!

Do exactly the same procedure with the front ring.
You’ll get grease all over your fingers and your barrel, but it doesn’t matter!
Once the rings are in place, remove the excess grease and clean the outside of the barrel with iso alcohol.
If everything has been done correctly, the guides should be in their original positions.
Degrease if necessary, and refit the guides without overtightening.
Secure with a little varnish.

To enlarge, click on the image ( 2 photos )

At this stage…
Check with the calliper that your measurements are identical
before dismantling.

Refit the aperture ring,
the aperture drive ring,
bayonet without tightening the screws.
Set the point ramp to infinity.
Screw the front optical unit back on without overtightening.
Mount the lens on a housing and check the infinity.

To enlarge, click on the image ( 2 photos )

Focusing is Just ???? Yes ! …
Then it’s almost done!!!

Refit the front lens and bayonet.

Refit the front light unit and bayonet.

Loosely tighten the guide screws and apply a dot of varnish.
Refit the bayonet, applying very little threadlocker before completely
screwed back in completely.
There is no need to force the screws, as the threadlocker will jam.
Blow away any dust in the aperture block and rear inner lens.
and the rear internal lens.
Refit the optical compartment, tightening it correctly but not too much.

Fit the focus ring and the clamping ring,
(I use two toothpicks to hold the ring in place and position the first screw).
and position the first screw).
Tighten the three screws with a varnish point.

To enlarge, click on the image ( 1 photos )

All that remains is to reassemble in the reverse order of disassembly….

To enlarge, click on the image ( 1 photos )


This tutorial is intended to help you find your own way!

There are also professionals to do this work 😉

Lubrication of helical lens ramps