Differential gear device

A differential gear device comprising:

• a differential casing rotatable about an axis and having a pair of through-holes;
• a pinion shaft accommodated within the differential casing, so as to extend through the through-holes;
• a pair of pinion gears fitted on an outer circumferential surface of the pinion shaft such that the pinion gears are rotatable relative to the pinion shaft;
• a pair of side gears meshing with the pinion gears;
• and a pair of pinion washers interposed between the differential casing and the respective pinion gears,
• wherein each of the pair of pinion washers has a retainer structure partially inserted through a gap formed between an inner circumferential surface of a corresponding one of the pair of through-holes of the differential casing and the outer circumferential surface of the pinion shaft, the retainer structure being held in contact with a corresponding one of opposite axial end faces of the pinion shaft, to prevent axial movements of the pinion shaft through the through-holes.