Originally posted by pentasonic49 Put "sdm repair" into the forum search, if you are good at taking things apart AND reassembling them successfully, then you could save yourself a lot of money. I've had my 16-50 apart twice, the second time to drill holes so that the motor could be reached without taking the bloody thing apart a third time. It seems to get better with age, although I do regularly run the focus motor to stop it from sticking.
I've used the disassemble, free the SDM motor method and found it works quite well.
if i need to repeat the process i'll take on board the idea of drilling the mount and the second retaining plate, to create permanent access to the SDM.
this will not compromise the weather seal as the hole will be inside the gasket on the lens mount.
hopefully it will be a while before this is needed.