kuhn gmd 700 gII HD or jd 275 disk mower pto turns but do not turn the belts or blades

pto turns (some squeal) and nothing else turns.  no belts or blades.  can't seem to find anything in the book on this oils look good.  for what it's worth "it was working yesterday when i shut it down".  does anyone use 75/90w for the bars or gear box on this kinda mower. thanks much

 

kuhn gmd 700 gII HD or jd 275 disk mower pto turns but do not turn the belts or blades