Since Lippert now is the 'proud' owner of Dexter Axle, I suspect that those wheel bearings are the fail prone Nevr-Lube but with a different name. There are two versions of that crappy bearing, 42mm and 50mm with of course the 42mm being the weaker - and exactly the same capsulized piece of junk that many, much lighter automobiles use world wide. The permanent fix is to contact Dexter, not Lippert, and discuss with them as to how they can help you with a new pair of E-Z Lube axles (the Nevr-Lube axles cannot be retrofitted). Yep, it will cost you some pretty steep bucks, but peace of mind passing through West Overshoe, Middle of the USA is well worth that outlay. To the detractors that say they have never had a problem, just wait. Keep your trailer long enough, you will.
Nevr Lube's - about to fail:
Replacement E-Z Lubes - notice a LOT more area for bearings vs 1-3/8" for the other: