Adjusting the torque motor on a canon 518sv

[StevenBradford]

Has anyone had experience adjusting the torque motor the Canon 518SV. I've got about 20 of these, some of them have no problem but several just don't want to pull the film sometimes. Disassembling them, I can see the drive axle slipping in it's little brass gear, but can't figure out how to give it back the traction to pull the film. I know I can just buy another one on ebay for $30, but I hate retiring a good camera with a working meter.

It's funny the original Canon 518 rarely has this problem, but the SV is better in most other ways, low light and full daylight exposure range, no button batteries.