Mamiya 90mm f/3.8 (1973): Excess Moly Lube in the Shutter
Originally posted on Instagram. Notes from the repair bench, kept here as a searchable archive. View the original on Instagram
Servicing an early version of the Mamiya 90mm f/3.8 lens (1973). Shutter was sticking (delayed release) and needed disassembly and cleaning off of lubrication.
Photo three shows how moly lube was applied excessively to the shutter housing. Some people think that lubrication is the answer to most shutter problems. It is not. Correct procedure is a good cleaning and then very light lubrication which should be barely visible. Photo four is of a Hasselblad shutter that I serviced and that the customer advised me just had a recent so called “CLA”. As you can see, lots of molylube everywhere. Very sloppy.
On the Mamiya that I just finished, there was also lubrication on the sync contacts which was causing a problem with the flash connection. Photo five shows the contact efficiency on initial testing, 2%, which would not fire a flash. After service, photo six shows efficiency at 83% which is within specs.
