How to Lube Ball Screw?!?!

[bcromwell]

Two of my Ballscrew's have zirk fittings on the face of the flange, no problem to lube. The third has a 2mm hold on the side of the flange, no fitting/hole on the face. Looks new/refurb. and when I turn the screw I can hear the balls moving like there is no lube inside at all. Any chance the 2mm hold is the fill point? My "needle" tip for my grease gun is closer to 8mm so I wonder if I need a special tip/adapter. 1.5" screw fyi.

Picture show the little hole and the PITA place it is located