Dale M. wrote:Once a year at beginning of season seems reasonable interval for a boat trailer....
Dale
Actually that should read "at the end of the season" otherwise if the grease is contaminated the bearings will have all of the off season to corrode and pit.
While I have always packed extra grease in my hubs,I never pack them fully. I went through a clinic put on by Dexter axle on packing wheel bearings a few years ago. The tech pretty much packed a little grease in the bearing and smeared a little more on the outside, no grease in the hub at all

When asked about the amount of grease, he said that's the way they are done at the factory and there is seldom a bearing failure.
I have 2 trailer that came with Dexter "Easy-lube" axles, the one with a grease zerk in the end of the spindle. I never use these for two reasons, one I like to inspect my bearings and 2, if I wasn't the last one to put grease in, there is no way to know if my grease is compatible.