PURPOSE: To provide a optimally strong and lightweight differential gear, in which cost is reduced and which can be easily assembled by supporting an axle shaft gears engaging with differential gears on retainers which receive forces acting in the direction of an axle.

CONSTITUTION: A differential for the axle drive has a differential gear case 2 supporting a drive gear 1. Shaft pin 7 supporting differential gears 8 is supported in the differential gear case 2. The differential gears 8 are further engaged with shaft gears 9 provided on an axle shaft 10, and these gears are formed as bevel gears. In this constitution, the axle shaft gears 9 are supported on retainers 12 which receive forces acting in the direction of the axle shaft 10. The drive gear 1 formed as a ring gear is provided in the range of a longitudinal axis line B-B passing through the shaft-pin 7. Furthermore, the differential gear case 2 is formed of pot-like members 5, 6 which are joined to each other and which are rotation-symmetrical, and the ring gear 1 is mounted in the range of a joint part 15 so that it can be easily loaded and removed.