Well...for what it's worth I put my trailer up in the air (the frame on blocks )every winter.
In the spring I rotate the wheels for awhile to get the bearings, grease heated up and I choose a warm day ----and I pump in new grease into my EZ Lube hubs.
Amazingly enough the old grease comes out (right where its supposed to ) .by using a hand gun I can tell just how much pressures. I use.:W
Not a big deal if you do it like were supposed to.:R
Every other year, I pull one,(in a rotation).....just to see how brakes and seals are.
Now those of you who have problems ----well don't know what to say....:h