Gerald is right, but your owner's manual may be like ours - it needed some updating prior to publishing.
The maintenance schedule listed refers to checking the "level" every 1000 miles or replacing the 90 weight gear oil every 30,000. As you know, you don't have oil bath hubs, so that info is irrelevant. A closer look deeper into the manual's Chassis section reveals text that says, front axle "wheel bearings should be cleaned and repacked with high temperature disc brake grease every 30,000 miles."
I've used kerosene and parts brush in a small container or disk brake cleaner to clean bearings with.
I'd call Loren in Bend for a recommendation on what's really the best grease.
-Joel