We were a couple hundred miles into our last trip, when I noticed a missing hub cap. Luckily we has zip-lock bags and a large hose clamp. We stopped in Junction City, at New Horizons, and had a new cap put on.
I called Morryde and asked how often and how much the grease zerks should be greased. They said, without any doubt, do not ever grease them. So I asked why would they have installed grease zerks they didn't want greased? The answer was their supplier puts grease zerks on them, but they shouldn't be used or it will push the seals out.
We stopped at New Horizons on the way to Colorado, they repacked the wheel bearing and installed a new dust cover.