For those of you with cool hubs here is some simple maintenance. My rig is a 96 ranger. The hub does look different then the new models but the steps show should be very similar.
Remove lug plate and wheel.
Notice my hub is offcolored. It is leaking and allowing water in but in the end it was very minimal.
Locate drain screw on top of the hub. Unscrew and allow to drain.
If I had more water in the oil I would pop off the silver cap remove and replace the O ring and continue on. Notice the O ring is not in the greatest shape. This is probably where the water is getting in.
Refill with the proper oil called out for your model. Mine is 50wt.