After posting this last night, I thought the replies would be that we did not pack the bearings. My husband and I are overkill on the maintance we provide on our trailer, check list and follow it every time we camp.
He was a mechanic and packing the bearings was done. In fact, when we finally were able to have it looked over, all of them were packed already. The other point I did not mention was we upgraded the axel size from Lippert 3300 to Dexter 5200, just looking at the size of the bearing, it was a no brainer. Perhaps some will take away from this that maintance is key, or consider everything when deciding on a camper, including the parts underneath as well. Like I said, information is key and that is what I wanted to put out there.
Sometimes stuff just happens. If your hubby was a mechanic he should
know how easy and inexpensive it is to carry a spare bearing and the tools to change it and to use an infra red temp probe to detect bearings that are not performing as they should. You say you had
two bad bearings. That is odd!
The bigger issue, I suspect, is that as a mechanic he knew the bearings should last a lot longer than they did and was not ready for the failure. Mine are five years now with no maintenance so far but I will repack this winter (Dexter). Going with larger axles is good, still they need to be maintained. Dexter has a good reputation so hopefully your problems are over.
We were not there when the OP purchased the trailer. But, I suspect if the axles were some kind of EZ lube the salesforce said just add some grease occasionally and the bearings will receive lubrication. This is not the same as taking the bearings out and checking them and the races and then repacking and putting it all back together. Just adding some grease is not a bearing repack. Adding grease to a failing bearing still is a failing bearing. It does not fix a bad bearing.
To save your family a second headache you might review on this forum OEM ST tires if that is what is on your coach. It will be enlightening as well. If your coach is about three years old the tires could be four from the date of manufactur and that is about all some ST tires will reliably last.
Also, going the Dexter route get the EZ flex spring equalizer and the wet bolt kit to replace the cheap plastic bushings and allow for periodic greasing of the bushings. After three years the OEM bushings are probably gone as well. The kit is about $175 and well worth it.