After sitting over the winter, the clutch on my 1965 Case 530 Diesel won't disengage. I can see that the pressure plate releases as normal. I'm sure that the friction disc has simply locked to the flywheel due to moisture, rust etc. after having sat engaged for 6 months over the winter, it always worked fine in the past. I have run the tractor to try to jar the plates loose, lots of jerking back and forth in all the gears including 4th and reverse. I'm reluctant to try to load the drive using the bucket or to try to tow something heavy, safety concerns. Does anybody have an idea other than splitting the tractor? Thanks in advance.