Simplicity Legacy 27 XLS 4wd Diesel won't move

[oneup2u 0]

Being new to hobby farming I bought a used Simplicity Legacy 27 XLS 4WD Diesel. After a couple weekends of light duty mowing and moving, I had had no issues with it. Then, I was using it to haul manure to the garden to fertilize with when I noticed the reverse suddenly became very weak. I dumped the loader and tried to back out but reverse was gone. I was able to pull forward but not far before that too, went out. Now the tractor is sitting in the garden and will not move. It starts fine, loader, deck and PTOs work fine but no forward and reverse. I removed the deck and got up underneath. I do not see any hydraulic leaks. I did trace the linkage from the pedals to what I'm guessing is the rear transmission and there was a lever that actuated forward and backwards when the pedals are moved that did not appear to be seated as the bolt was loose. I tightened this (see pic) but that did not help. I also made sure the transmission release was pulled up and back. Its model 2690289 and any help would be appreciated.