Hello friends. Im taking on the task of restoring a few M3's that need adjusting and cleaning. I purchased on ebay copy of Leicas M3 factory guide. I have pretty much all the tools the guide suggests. What Im confused about is a tool the guide refers to often called the "Spring Tension Guage". Does anyone know what this is. I think its a torque screwdriver. The guide wants me to "Tension the shutter with the spring tension guage to 19 to 20". Thats all it says. Please help decipher this. Thanks to you all. Cheers, Henry
You are thinking in the right direction, but the gauge is far more sensitive than a torque driver. I have not got my M Series repair manuals to hand and it is a long time since I read them in detail, but I seem to remember that the units are grams. Anyway this is a minor problem since most people tension the springs by rotating the shafts a specific number of turns. A Google search will come up with plenty of sound information. However Tomosy gives a very good write up in his book on restoring classics.
The following Google Book link gives you the full details -
Thank you Glenn. I also asked Youxin Ye about this tool and he also did not recommend a torque driver. He said to just adjust the tension until the shutter speed is correct using a shutter tester.