I had a hub go out this past trip. Got to call out the folks at Tom Raper RV in IN. I believe Doug was the tech and Daryl was the service manager. I was in and out over 3 hours on a Monday morning. 1 hub replaced and 4 packed.
I had help a friend RVers - as he pulled into the rest stop I informed him that his RV sounded like it was dragging a pipe. Like it was rolling a pipe over the ground. He whipped out his IR meter and did his hub and tires and mine. Said I had one hub a little warmer..... I gave him my hitch grease, hoping it would help out.... it's odd how Karma works... 3 hours later I pulled in and my hub was bad. Luck or karma not really sure but not going to question either.. around $300 for 4 hubs greased and 1 bearing replace....
I had my hubs done in 2011 at local shop. It's cheap insurance, especially if you are taking an extended trip and have not had them done in a while.