Hi BrentW,
Does the center spindle shaft have a spacer pipe to make sure the tapered roller bearings are not bottomed out in the races and over tightened, it should. If tapered roller bearings are too tight of a fit, the grease will not get in to lube them properly.
In my humble opinion it is worth the trouble to have all the parts laid out and then pack grease in (and rotate while packing) all taper bearings by hand before install to make sure enough grease get to the inner race of the bearing itself. That step makes a huge difference in the life of the bearings.
Pre-assembled units do not come prepacked by hand and simply pumping grease in will take hours of run time to heat up before the grease moves enough to get where it is needed most. This excess heat creates initial damage and shortens the life of the bearings and races.