Every 2-3 years I pull both wheels, clean things out carefully, and then repack with new inner seals. I do my best to get enough grease in, particularly around the seal, so that it will never run dry and start to leak. The double-lip inner seals were about 20 bucks last time I did it. It will probably take a couple of hours or so to do this start to finish. Probably the biggest headache is getting the hub cover / bearing-buddy off. A good “dead blow” hammer is a start. Once that is removed the rest is easy, if messy.
My current boat / trailer is a 91 model, and I have never had a wheel issue of any kind other than once or twice losing a valve stem at the ramp where some idiot put rip-rap under water to block his trailer so it wouldn’t roll for some reason, and it just hit my wheel on the edge and apparently flipped up and ripped the valve stem off. Since I started the regular maintenance, I’ve not had any bearing issues of any kind. No water intrusion. No running hot. No galling. Nothing.
To remove the “bearing buddy” ttype hubs, I rap them with a dead blow (lead pellet filled hammer so there is no bouncing) to one side which will open a gap. Then on the other side. repeat and you can “walk it out”. Or you can use the crack between the hub and cover (produced when you rap it with the hammer) with a big prybar or screwdriver to help get the thing off. It is a strong interference-fit joint so its a pain to remove. A lead hammer is the best choice so that you don’t actually break the bearing buddy (they are tough, but if you try hard enough….) Once that comes off, the spindle nut can be removed and the hub will come off with the bearings leaving just the spindle and grease behind. Clean everything up. I replace the seals whether they look perfect or not, “just because” since it is pretty cheap insurance. Just get the seals from BCB or from a local marine dealer, as auto parts stores don’t usually keep the double-lip seals and using the wrong type can invite water in…

