Fix Stuttering Garage Door Opener & Replace Thermostat ( Optional )

My B&D Controll-a-Door Power Drive has begun to jerk and hesitate almost every time it heads upward. The stutter is most noticeable on opening, and you can clearly hear a sharp smacking-style clatter in the short video I can share... (Budget: $250 - $750 AUD, Jobs: Electric Repair, Electronics, Mechanical Engineering)