I'm just giving you a heads up on greasing.
A press fit zerk fitting is not screwed into place. As there are no threads. So there are no torque specs. You have to either press them in, or beat them in. I have used a socket, extension and a hammer to tap them in place.
Problem you may have is a slightly bigger hole then what is called for. Or the zerk was undersized. One is the reason why the zerk fell out.