DR Field and Brush mower won't reverse

I have a 15 hp Kawasaki DR Field Mower about 02 or 03 model, went to fire it up to get some work done this weekend and the thing wont move in reverse. It will shift into reverse but no movement. All 4 speeds work going forward.

I followed the operators manual instructions on how to possibly fix it but it didn't work

Instead of pulling the tranny and taking it apart, maybe theres a simpler solution to be found here

Thanks for any ideas