The roller cone is retained to the head with axial play taken out of the bearings with a tension rod tensioned from the rear of the head and away from the nose bearing region of the head allowing greater resistance to loading in the region of the nose bearing and a reduction in critical stresses. The tension rod has a flat oriented for tightening and facing grease passages to allow grease to gain access to the bearings through the bore for the tension rod and otherwise fill the bore so the tension rod actively supports loading in the head bearing. The nose bearing is separately directly cone supported with a retainer threaded to the cone or a spacer between bearings can be used so that tensioning of the rod takes out the axial play in both bearings with force transmitted to a retainer at the back of the cone.