2017 cub cadet challenger 700, no reverse

[bent wrench]

I hate to be the guy that only comes here when he has a problem, but here I am. My father has the challenger 700. He had trouble getting it in reverse when he left home, when he went to leave my place it would not go in reverse or neutral. I unhooked the linkage where it hooks onto the.... whatever it is. Sorry, I'm no mechanic. I put a small wrench on the piece where I removed the linkage and could get high, low and neutral, but still no reverse. I didn't yank too hard, it's, I think, 10mm, so no leverage. We put it in neutral and pushed it backward to get him turned around and wrenched him into high and he screamed for home, well not really screamed, he's 78, but he was hauling ***. So, my advice was a stick of dynamite, but he's looking for something less extreme. Does anyone want to take a stab at it? Thanks.