http://www.tandtrepair.com/15Class_S...anual_1591.pdf
Short of having that machine on a bench, I don't know what to say. That is a link to an adjuster's manual. It has drawings of how it is suppose to look. Maybe you can figure something out from it. There is a fellow who comes on board on occasion. His name is Rain. He has a blog that I subscribe to. He is very knowledgeable on these machines. Here is a link to his blog - maybe you can get in contact with him.
http://vssmb.blogspot.com/ I hope he will help you right on here. I have a 15 clone that occasionally gets itself hung up in that same area - I have to jar it and it is good to go awhile. I haven't explored it enough to fix it though - too much other stuff going on. Mine also needs a replacement tension.