:Wow1: ... please, let's not get pedantic.
Check out the Gen-2 hub descriptions here:
http://www.timken.com/EN-US/solutio.../Documents/Vol5Iss5_Tapered_Hub_Unit_Brgs.pdf ... Timken is the OEM hub manufacturer, you'll also notice a cross-sectional picture (albeit low res). Look up part SP450701 here:
http://www.showmetheparts.com/timken/ ... or navigate through their menus to a 2nd Gen Xterra and select "Product: Wheel Bearings, Seals" ... under the attributes tab, you'll see the gen-type listed.
It may be a press fit, but I maintain that in a pinch you'd be okay to drive on the (4wd) front hubs with no half-axle assembly installed ... even to get yourself out of a trail and back home again. This has been borne out by many users over on thenewx.org, some of whom I know directly (vs. the possible implied hearsay/conjecture of relaying info posted pseudo-anonymously on a message board) ... take the information as you will. At the end of the day, it's really not that hard to bring along a spare assembly ... or to hack up a used one and scavenge the stub shaft.