That is a good question, and I will have to defer to someone with more knowledge on the particular subject. I do not have a backhoe. But.................................in looking at your pictures, it looks as if part numbers 090 and 100 are in place. Each one of those parts has a small "return" that sits on on of the lower link arms, and moves up and down with the lower link arms. From your pictures, it looks like the movement of parts NO. 090 and 100 are blocked so as not to move. Or.................................................after looking again, maybe 090 and 100 are not in place. Let's see what someone who knows says.
Good luck with it. Sorry that I don't have a better answer for you, but I am sure that someone else will. By the way, the notes I added on the diagram/pic are for me, or the next owner. I put a copy in the box in which I stored the parts.