recently acquired this 300-U...has indep PTO ( big gear box thingy on back ) problem is when mowing and hit a patch of tough fescue etc, PTO sets up a horrible loud and increasing whine. Blades stop turning until mower is lifted from said grass.I have had the back cover off of the PTO and the bands look to be nearly new ( former owner maybe had an undisclosed issue also ). The drums look fine with no scoring or rough spots.Adjusted bands ( simple to do)..and have not gone any deeper into it until I find some knowledgeable tractor guys to diagnose.And whats with this seasonal disconnect thingy ( gotta drain trans twice a year to use) thank goodness it's gone..........Bill