Leica LTM Summitar with stiff aperture ring

Leica M39 screw mount bodies/lenses
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I have just received a 1942 Summitar which is optically in very good condition but the aperture ring is very stiff to turn. I am under the impression that this particular lens has not been used regularly. Is it likely then that the grease has gunked things up or could there be some other contributing factor? Any help from those who are more familiar with this type of lens than me would be much appreciated.
 
Do the diaphragm leaves seem to move OK without binding or jamming? Old congealed lubricant can easily cause the problem you describe, especially in a lens that old. Whatever the cause, it needs servicing. I send mine to Sherry Krauter. She sends them back like new!
 
Well, whenever I buy gear that old, I assume it will need a CLA. Yours apparently is no exception.
 
If you would like to try putting a little silicon spray on a Q tip & wipe it around the back edge a few times the turn the ring it might work free. I have done it 3-4 times on old lens & it works great. If not then sent it to Youxin for CLA.
 
They made the fit of the aperture rings on the Summar, Summitar, and collapsible Summicron very tight -- very slight clearance indeed. It needs a bit of grease there, and then the grease gets old and gunky, the aperture ring gets very stiff.

Great lens, worth paying a professional to clean it up right, assuming the front glass isn't full of cleaning marks. (It's soft "flint" lead glass, scratches very easily.)
 
I think it is a fairly common problem with Summitars. There was a post or two about this very problem and you might find them doing a search. One of mine was like that and I took it apart and relubed it myself. End of problem.

Bob
 
I had the same problem with my Summitar, especially at cold temperatures in winter the aperture ring was very stiff. After being able to unscrew the lens head (took some effort ...), I removed the two very small screws in the aperture ring, the ring itself and carefully cleaned everything using a cotton swap and some acetone. Works very well now.
 
Had the same problem

Had the same problem

I had the same problem with mine and Youxin took care of it in about 5 minutes.

I'm not recommending a DIY but if you want to get an idea of what's involved check this out (Post #6).

Good luck.
 
raydm6 said:
I had the same problem with mine and Youxin took care of it in about 5 minutes.

I'm not recommending a DIY but if you want to get an idea of what's involved check this out (Post #6).

Good luck.
Click to expand...

Yea that is the post I was thinking about. As always you have to know what your DIY skill level is before you attempt something. That said, this was pretty easy for me who is usually all thumbs with this kind of thing. If you have any doubts send it out for a CLA.

Bob
 
Ronsonal Lighter fluid on a cotton ball and run it around the joint. Repeat up to twice more if necessary. DO NOT FLOOD.

Mine has been fine for a year now.
 
It the grease has really hardened, lighter fluid won't solve the problem for very long. At least the grease on my J-3 was almost as hard as glue when I took it apart.

I confess it has helped tremendously on my Summar and Summitar rings. and they are still as smooth as the day I worked in that small drop a year ago.
 
Yea, try the lighter fluid trick first it may work. It did not work on my Summitar, at least for long that is.

Bob
 
Ronald M said:
Ronsonal Lighter fluid on a cotton ball and run it around the joint. Repeat up to twice more if necessary. DO NOT FLOOD.

Mine has been fine for a year now.
Click to expand...

I did this with my Summitar, just a touch of fluid and work the apperture it tightened up again after the first application but after the second it has been fine. Yes, DO NOT FLOOD!
 
raydm6 said:
I had the same problem with mine and Youxin took care of it in about 5 minutes.

I'm not recommending a DIY but if you want to get an idea of what's involved check this out (Post #6).

Good luck.
Click to expand...

I tried this, the aperture ring was a bit tight, but came off without too much coaxing. I cleaned it up with some lighter fluid on a Q-tip, put a scant amount of synthetic watch oil on the mating surfaces and put it back together. It is smooth as silk. :)
 
I have a 1946 coated Summitar with the same problem. At one point last winter, it had become impossible to turn the ring once it was out in the cold. But even indoors, it had never turned very smoothly. I had noticed that if I would lighten my finger pressure on the ring while trying to turn it, it made it a bit easier. It seems that the ring will distort enough for this to happen, since I suppose the tolerance between the two surfaces is quite close.

Anyway, I just finished dismantling the top part of the lens myself. Cleaned and lubed it with synthetic bicycle grease. And now it's working great! I'm so proud of myself that I had to brag to my wife about it. She wasn't quite as thrilled as I was though. LOL
 
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