Most likely you have a stripped gear in the operator. If you look at the operator (which usually sits in the center of the door opening about 8-10 feet back) there will be little white shavings inside the housing. You probably won’t even have to take the cover off to see these shavings. There is a nylon gear in most operators that strip over time or if the door is binding or not running smoothly. We stock several different types of gear kits in all of our locations and can service this for you PDQ! It is always best to look at the full functionality of the door and not just change out the gear kit. If the door is getting caught and the operator is straining to open the door, you will likely have another gear strip soon after changing it. We would be happy to look at your door and operator for you. Call us at 1-800-734-1401 to set up a service call.