Mark 20 drive shaft was only turning 1 1/2 turns then stopping. I found part of this stuck in the bevel gears. It’s magnetic. Does it belong somewhere? No damage done.
I assume you have the reverse gear out already if yo clean the housing you will see a cavity at the bottom of the housing where the magnet was pressed in it was to collect the shift grindings and prevent them from getting into the bearings > check the flat spring holding the clutch dog pin for loosness and replace it if it has unsprung