try this one
i have also found that if you lift the mirror there is a little hole on the left of the chamber that holds the lever for the mirror governor. if you point the syringe in the little hole you can use some oil to lubricate the shutter and mirror gears at the same time. of course the more you oil, the more messy it gets. be prepared to have the cameras out of action for a little while because the residual oil does leak onto the shutter curtain. i have had to wait a few days to make sure the oil dried out a little and spread sufficiently.
be patient, you may have to repeat the steps few times and you should wait a few hours between the tries because sometimes the oil just needs time to settle. GOOD LUCK!