Abstract: A gear system is provided to secure lubrication passages when the gear system is changed between driving, neutral, and parking modes. The gear system includes a planetary gear assembly, a hollow portion output shaft selectively engaged with a carrier such that the output shaft is configured to rotate with the carrier when the output shaft is engaged with the carrier. The gear system further includes a first lubrication passage formed radially at a first point on the carrier, a second lubrication passage formed radially at a second point on the output shaft, and a third lubrication passage formed between the outer surface of the output shaft and the inner surface of the carrier and configured to connect the first lubrication passage and the second lubrication passage.