No one should trust with your life the axle bearings coming out of the factory of Lippert and sold to Forest River. Service them after your first trip, if not before. They are lightly greased by Lippert when they are sent to Forest River and no grease is put in the spindles if you have zerks. The spindle nuts are put on very loose and allows the bearings and hubs to move back and forth and create a lot of heat. No one should take another trip in your unit until you fully removed and inspected and re greased or better yet replaced your bearings. I can not stress this enough. If you have not had issues and have never pulled your bearing, you are running on borrowed time.
2013 Forest River Salem Hemisphere SBT312QBUD
2001 CrewCab F-250 7.3 PowerStroke Diesel
SuperChip, BTS transmission, 6.0 Trans Cooler