Greasing bearings or ball joints or steering racks is not a perfect science. There is no flow path through and past each set of bearing cups, other than through a seal, and when you break a seal, any more you add goes straight out that seal. The best you can do is put JUST enough in until just before it breaks a seal, which is of course impossible to do. Like bolt torque. Torque it until it breaks then back it off a quarter turn. Do the best you can and add the least you dare. BTW, grease does not move in a joint due to motion or heat. It is designed to do exactly the opposite, stay in place. It only flows when frictional forces at the metal contact surfaces get the pressure/temp up enough to make it move/flow to lube the surrounding area. yes, putting grease in your front wheel bearing cover/caps to supply extra grease if the bearings run dry is silly. It just sits there in the cap.