I have an old beater of a horse trailer that I use to haul llamas. 5 or 6 years ago I needed to replace the brakes and found that they were an obsolete type and parts weren't made any more. That meant all new brakes. I decided to get new trailer axles with brakes. 3500lb axles are enough for my use and they really aren't as expensive as you might think. Of course they'll come with new bearings which solves the issue of this thread. The trailer was a bit low for bad roads so instead of the 4" dropped axles, I went with straight ones to raise the trailer. Those are cheaper anyway. When I dropped the old ones, under one of the U-bolts I found a crack in the axle going about 1/3 of way around it. A trip up a rocky road could have left me in a real mess.
About setting the bearings: I was taught to tighten them snugly then back off about 1/8 to 1/4 turn, depending on where the key hole lines up with the castle nut.
