I greased my front suspension at the weekend and spotted these prop shaft niples while the car as up on the hoist, how much grease do you pump in there and how often ?
I am guessing you do not pump in so much you can see it ooze out like you do with the Sliding pillars.

Cheers John
2011 4/4 - "Elrond"
2007 Elfin C3 Clubman - “Gimli”