I have a 2017 FD75 45' header. I bought it used and went to set spring pressure and wing balance. The right side has a frown to it. The problem I am having is the left side is rigid. It wont move up or down. I had a guy come and look at it that has used and worked on macdons for years. He cannot figure anything out. We moved the wing balance all the way both ways. We loosened the bottom pivot bolt and sprayed it with penetrating oil. The bottom locks r both down and the wing locks r unlocked. Any and all help is appreciated. Thanks for the input!