I'm having trouble getting full range of motion on the damper rod on my Dutchwest 2461. Any ideas for freeing this up other than continuing to hit it with Liquid Wrench, giving it some taps, and working it back and forth with some vise grips on the rod? Looks like they went to a threaded rod here instead of something a little looser that would be retained with a clip. Thanks in advance for any suggestions.