It seems everyone I talk to that puts reasonable miles on their trailer have had a "Wheel Bearing" issue. I pull a 20' toy hauler and never haul toys with it. I'm way under rated weight wise for my hubs. Yet I've had two wheel bearing failures and the trailer has about 50K miles on it. I repack the bearing religiously every two years or 10,000 miles on a repack......Yet I still experienced failures...As have so many more long distance haulers......(and some that don't tow long distances at all)
BUT!!!....How come in over 50 years of driving cars and trucks, and I've never owned a car that didn't go over 180,000 miles, (I was an on the road consultant, trainer) I've NEVER serviced a vehicles front wheel bearings (or rear bearings for that matter)....I've had a number of cars go over 250K miles!...And asking around, I've not met anyone that had either.
Interesting......