Thanks for all the info, it ended up being that the fiber gear is completely stripped down to less teeth than a 90 year old professional grandma boxer (
).
After removing the headliner by just shoving the sunroof back manually a few inches, I pulled the cable out by attaching my drill to the cable end, and screwing it clockwise until it separated from the motor.
The cable is in great condition. I've searched and searched, and can't find a new gear, sucks that MB doesn't sell them, mercedes source is always out, and the only option is junkyard or new motor.
Anyone have any leads or ideas of where I can get one? The motor still works great...
I'll obviously be cleaning the cable and re-lubing it too, even with no motor back there right now I can only open it halfway, and that takes some effort, no wonder the gear stripped!
Another thing that popped into my head was to have a machine shop copy the gear, but with metal. Has anyone ever done this? I assume there's a reason for the fiber gear, but I'm still not sure what it is...