Summaron 3.5cm/f3.5 LTM re-grease problems

Hi! I'm new here.
I recently bought a Summaron 3.5cm/f3.5 LTM made in 1953. The focus ring was a bit sluggish so I thought I'd clean and lubricate the threads. I loosened the stop screw at 1 meter and thought I could just unscrew the lens from the M39 ring after that. But the focus knob can't be turned more than a few millimeters past where the stop screw was. Is there another stop screw that needs to be removed or what's stopping it? Am I thinking wrong and do I need to unscrew the focus thread the other way, i.e. inwards and disassemble the entire optical unit?
I can't find any description of how to lubricate an early Summaron 3.5 LTM but if I just get it apart it should be easy.

Any photos? The summaron has the threads exposed when you focus with it correct?

I did just that three years ago and you unscrew the helicoid via the rear sleave that is held in place by four slotted screws. Make marks, take lots of pictures.
Dont just take the parts out, clean reassemble and then wonder why the lens cant be focussed to infinity! 35 mm have two interconnected helicoids. One to move the optical block, another one with different pitch to move the rangefinder inside the camera. Another sleeve connects them.

Just for clarity. I realize you say it's the LTM mount Summaron lens but which version of the body does it have? If you are not sure what I mean, check out this link scroll down a little and you will see two black body Leica M 8 cameras each with a different version of that lens on it. The earlier (smaller) Summaron body was specifically made for LTM cameras and has a more 'pre war" look to it. The slightly later body with a more modern looking body was mainly intended for M mount cameras in the post war period but some earlier versions of this were also in LTM mount.

peterm1 said:

Just for clarity. I realize you say it's the LTM mount Summaron lens but which version of the body does it have?

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His description of what he tried clearly enough indicates it's the old version with the stud you can just unscrew and which looks like it's the only thing keeping the helicoid from unscrewing. Tried the same thing at first.

The threads are visible when you focus to infinity. When focus at shortest distance there is one small screw visible (arrow on next picture). But you cannot reach it. I wonder if this screw has to be removed. If so I probably need to take out the lenses as well. Has anyone re-greased the focus coil on this type of lens without removing the optics?

I am not sure, but I would have thought with that style lens as long as you remove the infinity and minimum focusing distance "studs" the lens should just screw out, but you will have to make sure you mark down where the lens screws back in

Ventura said:

The threads are visible when you focus to infinity. When focus at shortest distance there is one small screw visible (arrow on next picture). But you cannot reach it. I wonder if this screw has to be removed. If so I probably need to take out the lenses as well. Has anyone re-greased the focus coil on this type of lens without removing the optics?

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To repeat myself: Remove the four screws on the back of the lens. Please don't if you feel this is beyond of your understanding of how the mechanism behind it works, which I also described above. In the picture some retaining-rings have already been removed which isn't necessary to get to the helicoid.



My memory returns bit by bit and if it doesn't fool me, you can unscrew the helicoids after removing the sleeve connecting them. Maybe the outer retaining ring has to go too. Take note in what position the helicoids separate. You can do it in 4 different positions and focus will be off if you enter the threads wrong.

Thanks for the clarification. Then it's not quite as simple as I thought. What grease did you use? I'm considering Japan hobby tool's #10.

skahde said:

To repeat myself: Remove the four screws on the back of the lens. Please don't if you feel this is beyond of your understanding of how the mechanism behind it works, which I also described above. In the picture some retaining-rings have already been removed which isn't necessary to get to the helicoid.

View attachment 4890565

My memory returns bit by bit and if it doesn't fool me, you can unscrew the helicoids after removing the sleeve connecting them. Maybe the outer retaining ring has to go too. Take note in what position the helicoids separate. You can do it in 4 different positions and focus will be off if you enter the threads wrong.

Click to expand...

Thanks for the clarification. Then it's not quite as simple as I thought. What grease did you use? I'm considering Japan hobby tool's #10.

Klüber Catenera KSB8 was a perfect match. Don't let this put you off completely, it is less hard than it may sound and the lens is easy to work on. Solid threads, good materials, logical arrangements. Just use good tools, take your time, make lots of photos or even better videos and set marks where and how parts separate.