“Completely full hubs actually run hotter than normally packed bearings”
Why would that be?
Several years ago I replaced my axle. The new axle is made by an outfit called Dexter. There’s a grease fitting right on the end of the spindle, which leads to ports that come out between the inner seal and the inner bearing. I jack up the trailer, start pumping grease while I spin the wheel, and push all the old grease out through the front. I’ve haven’t ever seen any water comes out, and the whole hub is packed full of new grease when I’m done. Checking the hubs when I’ve been out on the road, like at a rest stop, the hubs have been cool to the touch.
S.R.
I learned to pack bearings during my apprenticeship in a heavy duty shop. We used a pneumatic packer for the bigger bearings but hand packed the smaller ones. I was told the only reason to grease the inside of the hub (and the spindle) was to prevent corrosion. However, boat trailer hubs are routinely fitted with grease caps like EZ Grease Caps and those hubs get completely packed, so pick your poison I guess. The advice to do your packing over a clean rag is a good one, and also CLEAN YOUR HANDS before doing this, especially the palm of the hand holding the bearing. Otherwise you’ll just transfer all that grit and grime from your palm right into the bearing.