I doubt if you have Never Lube as the are an expensive option. Just look at the hub ends they should be marked if the are.
If you are going to remove the drums for inspection do this first. With the trailer jack up grab the tire at the top and bottom and shake it. You should feel slight movement. That slight movement is the correct bearing tightness so if you have never set bearing before at least know what the end setting should be like. When tightening bearings with the wheel mounted rotate the wheel slowly as you tighten the castle all the way with a pair of channel lock pliers. Now back off about a 1/8 of a turn and test the movement as noted above. If god insert the cotter key and fold it back. Real tight bearings will burn.
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles