The axles with the fitting in the center can work but... You have to jack the wheel off of the ground and rotate it while greasing and the grease should be forced forward to the frt. bearing. It seems the void between the 2 bearings has to become filled with grease before any reaches the front bearing. I grease the fitting periodically but still pull the drums and ck brakes, replace seals and pack bearings every other year.

68 and EMAN do it right.

The drums have to come off, inspect the brakes, clean everything, inspect the bearings, repack by hand with the best grease available.

Pumping grease through the axle fitting is easy, YES it is, but it is asking for trouble.

The grease in the bearing is the only grease that is doing anything, the rest is just along for the ride.