DRIVE UNIT

A drive unit mounted on a vehicle includes: a motor; a motor-side shaft having a first spline on an outer peripheral surface thereof and rotated by torque from the motor; a gear-side shaft having a second spline on the outer peripheral surface thereof and disposed coaxially with the motor-side shaft; and a coupling sleeve disposed from the motor-side shaft to the gear-side shaft and having a third spline on the inner peripheral surface thereof that engages with the first spline and the second spline. The coupling sleeve is configured to be movable along the axial direction, and at least one of a first engagement length in which the third spline engages the first spline and a second engagement length in which the third spline engages the second spline varies according to an axial position of the coupling sleeve.