Being a farmer I've seen my share of grease vs. greaseless. With the idiots I employ, grease it means 4 or 5 shots til the u pops and oozes.
Even after ordering them just 1 maybe 2 shots, they revert back to old. Now I'm not saying you do this but it doesn't take much to pop the seal and allow all kinds of crap to enter the u or pillowblock or whatever! Long ago I've gone to greaseless whether or not it has a zerk. Unless the u has any angle, once or twice a year is fine unless centrifugal force throws it out. My 2 cents. 209