A bearing cartridge which is constructed not to be disassembled for re-packing with grease or otherwise and which may be quickly and easily replaced in the field. For high temperature applications such as sinter or pellet car wheels, the bearing cartridge is lubricated by a high temperature solid lubricant, and the rolling elements preferably comprise cylindrical rolling elements for bearing radial loads and spherical rolling elements for bearing axial loads. For ultra high temperature applications such as furnace car wheels, the bearing cartridge is lubricated by a ultra high temperature lubricant composed of a graphite and molydenum paste. In order to economically provide small furnace car bearing cartridges, a two-piece bearing cartridge is provided with rolling elements, preferably having cylindrical central portions for bearing radial loads and conically shaped axially outer end portions for bearing axial loads, between the races, the rolling elements insertable by means of a feeder slot.