axle, hub, bearing question

It does not take much grease in the bearing to do the job if the bearing is packed properly. It's the bearing that needs the grease not the whole inside of the hub. Boat trailers use bearing buddy's to keep pressure in the hub so as you back your boat trailer in and the hub cools quickly it creates a vacuum and can suck water in. I have packed wheel bearings for many years on cars and trailers and only a minimal amount of good quality of grease is needed. If you get the hub hot enough to get extra grease to flow into your bearing you have other problems. Just pack the bearing not the hub and service at recommended intervals.