Parts and repairs aren't getting any easier to buy. This will greatly increase the service life of new sealed bearings.
Before installing new sealed bearings, GENTLY pop out the seals from the side of the bearing. Using a well worn, (no sharp edges) small flat screwdriver should keep the seals damage free. Most bearings are lubed very poorly with thin grease sort of like petroleum jelly).
It's best to wash/scrub this low-quality grease completely out and re-fill, pushing the grease through from one side to the other with your favorite. Boat trailer spec. grease is great because of its moisture resistance.
The attached thumbnail pic are "before" pics. Nearly zero grease in one side of these new wheel bearings!