Mamiya C 80mm Chrome Lens: Oil in Shutter, Worn Speeds Escapement
Originally posted on Instagram. Notes from the repair bench, kept here as a searchable archive. View the original on Instagram
This 80mm chrome C lens came into the shop with a complaint of slow speeds sticking. My client said that he had taken the lens to a repair shop and they told him that the problem was not a lack of lubrication. And, that is true because after some disassembly, I found quite a bit of lubrication in the shutter!
Not a good sign when the shutter has obvious oil residue on the shutter blades and the shutter reeks of aromatic oil (WD40?). The first few photos show the oil on the blades and photo fours shows what the puddle of oil looks like once the speeds escapement has been removed. The entire speeds escapement was dripping in oil. The final photo is of the bottom of the speeds escapement and visible in the center of the photo is the worn/distorted gear shaft bore that was causing the initial issue. There is no amount of oil/lubrication that can fix this, the escapement needs replacing.
So, if you are repairing a leaf shutter, please, no oil. Anywhere. I remember reading an interview from a Seiko service manager some time ago and he said that the speeds escapements on the shutter was lubricated during manufacturing and no amount of oil should be put on the escapement in the field during cleaning and servicing.
In this case, the shutter was not repaired due to the extra cost of a complete disassembly to remove all the blades and clean oil from them and the surrounding mechanism.
