Garage Door Parts Diagram | Garage Door Parts Guide However, the garage door parts in this diagram are only the tip of the iceberg. By clicking on your specific part, we offer our detailed product reviews and recommendations. We provide you with sound advice when it comes to choosing which brand name to trust since there are probably hundreds.. The Many Parts of a Garage Door (Tilt and Roll Style Diagrams) Top Section: Includes the top panel of the garage door. Intermediate Section: Includes the middle part of the garage door. Door Arm: Device that closes the door. Door Bracket: The hinge below the door arm. Bottom Section: Includes the low panel of the garage door. Right Jamb: The vertical framing on the right side of the door opening.