New to PTO equipment…I have a 72” King Kutter on my L4701. One day while tilling my field I noticed the tines were just rolling with the tractor and no longer engaged at full speed. I shut down cleaned the tiller tines thinking I found some old fencing or something. Fired it back up and when I put it to the dirt it immediately stopped spinning. This brought me to pulling apart the slip clutch. Discs were pretty burnt, so I replaced them. Tried again and the tiller is stopping whenever I hit hard ground and the clutch doesn’t seem to be slipping. Pick it up and it spins at full rpm, touch down it stops but doesn’t slip. Not sure what else to try?