Steering Rack Lubrication

["Dan Eiland" <deiland1@elp.rr.com>]

Can someone explain why we use grease on wheel bearings and on steering
column bearings, while using gear oil to lubricate the bearings in the rack
and pinion and the differential? It would seem to me that the rack and
pinion bearing and the steering column bearing would share more load and
force characteristics as would the wheel bearings and the differential
bearings. I'm confused as to how the engineers chose lubricants for the
different bearings.

Dan Eiland