pentax Objectifs takumar User Manual

SERVICING A TAKUMAR 35mm F4 LENS

Introduction

I won one the original Takumar F4 35mm wide-angle lenses on eBay. The lens looked to be
in very good condition and was complete with the brown leather case and caps. Perfect or so I
thought! The lens duly arrived from the USA but I found to my horror that the lens was
completely coated with a very fine white dust. I checked the listing and the picture looked
OK. The reason then became apparent. The felt on the inside of the top of the case had come
adrift and the very old cardboard had started to disintegrate with age and rubbing from the
lens during transport. Not really anyone’s fault but a problem. I tried to clean it as best I
could, including, the case. However, an amount of the dust had got into the focus mechanism
and it was so stiff that it was almost impossible to use certainly without the lens coming
unscrewed just about every time you tried. As a service would have cost more than I paid for
the lens and there were no complications with stop down mechanisms, it was time for a bit of
DIY.

Disassembly

1. Remove the 2 screws shown in the photo. They both have
a piece of tube to act as a sleeve on them.

2. You should now be able to unscrew the
lens. It’s a bit like a continuous focus
adjustment. You should end up with 2
pieces like this.

3. Now remove the 3 screws shown here.

4. Remove the screw shown here and then unscrew these

two parts.

5. If all has gone well you should have 4 major parts.

Cleaning and Reassembly

The 3 metal rings are just that, so they went in a jar of solvent to get rid of all the old grease.
The “lens” part couldn’t be treated in this way for obvious reasons. The worst of the old
grease was wiped off with tissues and then some lighter fuel was applied using a cotton bud.
The grease was wiped off again and the process repeated. This time, I also used a clean old
toothbrush to make sure the grease was removed from the threads. It may seem obvious but
do not apply any fluid directly to this part of the body.

A quick “dry” assembly showed that everything was now free. Probably too much so!
Reassembly is pretty much the reverse of the above process with careful application of grease.
I used a very light synthetic grease. For the fine threads, very, very little needs to be applied. I
used a matchstick to put a small amount on and to roughly spread it before screwing the 2
parts together several times to spread the grease. For the coarser threads I used about a ¼ of
what I expected to use and again “dry” assembled to two parts. The lens focus was a bit too
free so I applied just a little more to get the right damping affect. It is much easier to apply
extra than to have to clean it all off and start again!

A word of caution, there are about 3 start positions for the coarse thread. If you get the wrong
one, the lens won’t line up properly and you can’t get the last 2 screws in. If this happens
gently unscrew it until the thread releases, turn about another 1/3 turn and try again. It took
me a couple of attempts to get the right one. The cardboard in the case was sealed with dilute
PVA glue and the felt reattached.

I now have a beautiful smooth focussing wide-angle lens for my Tower 26 (Asahi Pentax).