XOC,
Lubricating the hubs is a no-no. If you pack them with grease, they will cease to operate. As for feeling them engage and disengage, now that I think about it, I can't recall ever having felt them disengage but one time when I put the truck in reverse on a nasty sand hill and that was jsut a couple of weeks prior to the manual hub installation. I felt them disengage and reengage briefly when I had to go into reverse to back off of a tree root.