Door actuator sticky, motor ok - with video

Hi,

I have been having central locking issues on 3/4 doors on my wagon (2005 Legacy Sport). Threads on this forum (eg https://bit.ly/2RHh4g7) suggested the motors often get greased up and give out. I've taken a closer look at the back passenger door and the motor seems ok, but the mechanism seems to get stuck.

With the actuator plugged in to the electrics, I use the driver's door central locking switch. I flick switch to 'unlock' and the motor moves a little, flick again and it moves a little, flick again and it finally moves it's whole range. This is in the video: https://bit.ly/34oHbgR. I suppose either the motor lacks the power, or the mechanism has too much friction.

To test the the motor is functioning, I take the spindle thread off and put in back in the housing - the shaft spins just fine. I'm reluctant to tear apart the actuator any further to lube it as the mechanism has a stiff spring, and getting it back together with basic tools is possibly gonna be a pain. Also, it appears to have ample clean white grease.

Any advice at this point?

Picture: https://www.dropbox.com/s/5fmebcukkdi0tvj/IMG_7533.JPG?dl=0

Keylime