The installation of a full complement needle roller bearing is usually carried out using an auxiliary sleeve. At this time, the auxiliary roller or the auxiliary sleeve holds the needle without causing the needle to fall out, and the journal picks up the needle with its own chamfer. As the needle bearing moves slowly inward on the journal, the auxiliary roller Or the auxiliary sleeve will slowly withdraw until it is placed in the working position. The outer diameter of the auxiliary roller and the auxiliary sleeve should be 0.1-0.3 mm smaller than the shaft diameter. When installing, first apply the grease to the inner surface of the outer ring of the bearing, place the needle on the inner surface (the gap should be left when the last needle is placed), and then replace the auxiliary roller that replaces the journal or inner ring of the bearing. Or the auxiliary sleeve is pushed into the outer ring hole, and the end surface is aligned with the end surface of the mounting shaft or the end surface of the bearing inner ring that has been mounted on the shaft, and then the pressure is applied by a press or a hammer. Needle roller bearings can also be installed by applying a thin layer of lubricating oil to the outer diameter of the auxiliary sleeve and inserting the outer ring of the bearing so that the auxiliary sleeve and the outer ring of the bearing form an annular hole, and then the needle is placed in the annular hole. After loading the needle, push the auxiliary sleeve out with the working shaft.