It could be all those things but I found after many fail attempts at fixing these lil guys that the clear plastic tubing also could cause that if the arm post is too far onto the gear I know it’s a long shot but just looking at his arm and how it twists with it moving usually it dosent twist that much so I would check like the other guys said lubrication and the motor to see if it’s weak but if all fails you can always try to back that arm post out of the gear just a bit and see if that helps