I pulled the damper and put a new gasket on it. The damper has 2 stubs that stick out that allow it to pivot. On the left (handle) side the stub fits into a tab that is retained by a bolt. On the right side the stub isn't retained. There is a piece of metal retained by a bolt but it just sits over the stub. When I close the damper the right side drops down and doesn't seal. Is the piece of metal on the right side supposed to go around the stub?