The nipple you refer to only requires grease when you are running the separator with the electric clutch on the header drive shut off. With the clutch engaged the unit is turning as one.
Mechanic thinks the fitting on the gearcase lubes splines on primary countershaft for easier removal of shaft from gearbox.Owners manual and deere service online does not show this fitting.late model 9550 electric clutch were advertised as not requiring daily lubrication.I would like to know how much grease ,how often and what does this fitting lube