Q: I just purchased a WD-339621 Operator Bracket to replace the original bracket pulled out of the door. My door sections appear to only have a top rib, see pictures. Is the bottom of each section strong enough to attach the bracket to. Is this correct?
A: Yes, that is correct. The larger metal piece at the top of your panel is actually a U Bar and the little lip at the bottom of the panel is the rib referenced in the instructions. Your door just has an extra heavy duty point to connect at the top, and the standard rib at the bottom. You can screw it in to the U bar on the top of the panel and attach it to the bottom rib as seen on the bottom of your panel pictured.