I have a john deere L111 tracktor I was mowing I stopped and came back to mow later and the tracktor won't move. At all.. I move the release button in and out but nothing.. I check the belt it is running and moving the fan.. on the hydro. I assume it is working I jacked it up and the wheels turn but I can stop them by hand... so there is really no power to the wheels.. any thing to check is there a stuck valve?

Have you had either one of the rear wheels off ?

No I haven't had them off?

Check the pulley by the fan and make sure its still turning the input shaft going into thr transmission.

Yes the fan turns and when I had it jacked up the tires turned but I could stop them with my hand

When you jack it up spin one side the other side should spin oppiste direction ,check and see if wheel is spinning on axle.
The fan could be turning but the iput shaft inside the fan could be slipping under a load.

Yes the tires do turn the opposite way... but I will try and check and see if the shaft is turning with the fan... thanks..

Bummer the fan is turning with the shaft. So is there a valve of somesort the might be stuck? Can you tell me if I take the unit out and flip it over and pull that pan off will I be trouble with fall out parts or can I see if there is something broke?

Look where the rod goes that releases the hydro make sure its moving in and out when you push the rod.
Jack up one side and see if you can turn it with the other side down on the ground,if so look and see if the axle is turning inside the wheel,
But yes if you take the transaxle
Apart there is a good chance that you will pull out some gears and bearings when you split it,
LUCK