If you have, have you had your bearing inspected and repacked. We have towed over 25K miles and have had them inspected and repacked at about 12K. We then spend over 4 months on the road traveling over 13K miles. Wanting to take a short trip we prepared and left, about 3 miles from home the inside rear wheel left for the woods and have never been seen or heard from since. Bottom line have the bearing cleaned, inspected and repacked every year or so.
See picture of all that was hanging on to the brake back plate.