I think that one of the main problems, is getting the system full of grease during the repack. If you do it yourself, flush the old grease out and fill every nook and cranny with new. Then before you put on the cap, you grease through the EZ lube system. Slow, careful while spinning the wheel. No way it takes a tube, I got returns on 4 wheels with 1 tube of grease, but I was lavish with filling from the tubs. Then each season, just a couple of strokes should get a return. When you feel the urge, tear down and repack again.
I think all new, or new to you, campers need a tear down and repack. After about 10,000 miles I found a dry bearing when I repacked my new camper. I haven't a clue how it lasted that long. It was a nice pretty blue color, it would not have lasted much longer.