Hydra Power Drive seems to have just gone out instantly. Clutch seems to be operating properly. Hydra P Dr turning when clutch out and making grinding sounds. Removed chain coupler to trany and both joining gears seem to be still engaging the shafts at least by hand. Loosened filter on Hydra drive and seems to be near no preasure at filter and yes level is up. Not sure if it was in hydra or direct drive when I loosened it, may go out and try the shifter to see if same result. Tractor was at a low idle at the time. Realize I'm probablely looking at pulling motor clutch and drive but looking for an idea of whats wrong as I am just quessing here and would like to have a better idea before I jump into pulling the motor again.