Abstract: A differential gear set assembling method includes: a pivoting step of closing openings by guide portion and pivoting a pair of pinions between a pair of side gears; and an insertion step of inserting a pinion shaft into a pair of case shaft holes and a pair of pinion shaft holes from outside the differential case. The pivoting step is performed in a state where projecting portions are buried in the guide portions. The insertion step is performed in a state where the projecting portions are projected from the guide portions toward the pair of side gears, and the pair of side gears are pressed by the projecting portions so as to apply loads against biasing forces of coned disc springs to the pair of side gears.

Abstract: A moving range measurement device of a side gear used in a differential unit, the differential unit including: a differential case; a side gear arranged inside the differential case; and a spring that biases the side gear in a direction parallel to a central axis, in which: the device includes: a jig in which a slope is formed, the jig being slidable in a direction vertical to the central axis of the side gear; and an actuator that slides the jig, and the actuator slides the jig to make the jig move toward the side gear in a state in which the slope is in contact with the side gear, to thereby move the side gear along the slope.

Abstract: Disclosed is a dummy shaft which prevents washers from falling off. In addition, disclosed are an apparatus for assembling a differential unit using the dummy shaft, and a method for manufacturing the differential unit. Specifically disclosed is a dummy shaft for temporarily assembling a differential unit by being inserted into a pinion gear, and a washer in contact with an outer surface of the pinion gear, including a body portion, and a movable portion slidable in a direction toward or away from the body portion. The movable portion has a receiving groove for catching the washer.

Abstract: A differential gear set assembling method includes: a pivoting step of closing openings by guide portion and pivoting a pair of pinions between a pair of side gears; and an insertion step of inserting a pinion shaft into a pair of case shaft holes and a pair of pinion shaft holes from outside the differential case. The pivoting step is performed in a state where projecting portions are buried in the guide portions. The insertion step is performed in a state where the projecting portions are projected from the guide portions toward the pair of side gears, and the pair of side gears are pressed by the projecting portions so as to apply loads against biasing forces of coned disc springs to the pair of side gears.

Abstract: A moving range measurement device of a side gear used in a differential unit, the differential unit including: a differential case; a side gear arranged inside the differential case; and a spring that biases the side gear in a direction parallel to a central axis, in which: the device includes: a jig in which a slope is formed, the jig being slidable in a direction vertical to the central axis of the side gear; and an actuator that slides the jig, and the actuator slides the jig to make the jig move toward the side gear in a state in which the slope is in contact with the side gear, to thereby move the side gear along the slope.

Abstract: Disclosed is a dummy shaft which prevents washers from falling off. In addition, disclosed are an apparatus for assembling a differential unit using the dummy shaft, and a method for manufacturing the differential unit. Specifically disclosed is a dummy shaft for temporarily assembling a differential unit by being inserted into a pinion gear, and a washer in contact with an outer surface of the pinion gear, including a body portion, and a movable portion slidable in a direction toward or away from the body portion. The movable portion has a receiving groove for catching the washer.