[dfkrug]

When I got the tractor, the clutch friction disk, press plate, and
flywheel were together in a box, and filthy with dirt and oil. When
I pulled them apart, I found my first major problem.

A closeup of the friction disk shows that the male splines have been
turned into sharp teeth. The clutch had become oil contaminated,
big time. So my working theory was that seal between the clutch and
primary gear box had failed, causing oil to get into the forward part
of the clutch housing. BTW, this also means that the trans input
shaft was also toast, as can be seen if you look closely at the splines.

This spline shaft shows one of the 3 bevel gears that comprise the
primary trans, which seems to serve only to lower the main drive shaft.
It increases speed by a ratio of 1.15. Because the gears are beveled
(for noise reduction I assume), the horribly chattering clutch served to
put excessive end thrust on one of the gears, distorting one of the spacers.
I am glad I checked for that.

As for my working theory of failure, it was wrong. The engine crank seal
had failed, dumping oil onto the clutch. Now I wonder if this violently
chattering clutch somehow precipitated the broken gears I had in the
main gearbox?