I have found in the past that hubs that came with grease nipples already installed from the manufacturer are easier to maintain and rarely need bearings replaced but just checked for adjustments .
I decide to put them in the Toro pro force blower hubs today . To install a grease nipple be sure to drill in an area that misses the race on the back side of the hub . In this case I also felt where the welds where that stops the race . I drilled a 7/32 hole between 2 welds . Top pic I'm tapping threads for 1/4 - 28 thread .
Pic of the hole missing the race .
I use a little loc tight on the threads of the grease nipple .
Repack the bearing and install a new seal and put back on axle .
Repack the front bearing and install the nut and adjust according to specs then lock in place with a new cotter pin . I'm greasing the bearing filling the cavity up between the races . I found this grease nipple a little short on this hub .
So I went with one a little longer . This is where it's nice to have a good supply of hardware goods on hand .
Now I can top up the grease once in a while forcing water and debris out of the bearings .