Well it was time for new bearings and with wider tires thought I'd go to an 18 bearing set up. I made my own enclosed cages and filled the center with grease. The outer bearing is still exposed to the elements but the inner one is completely sealed. I liked the idea of having the through bolts sealed in grease as well. Less chance for leakage. I seal welded a flange on each side of the cage (pipe) to eliminate leaks there too, and siliconed the flanges together. Also put a purge plug on the bottom of the housing to relieve pressure that may build up during use or while greasing.