Power transmission system for vehicle including a differential

A differential gearing 2 of twin differential type including a center differential unit 14 of planetary gear type and a front differential unit 12 of bevel gear type which are received within a housing 10 is separated from a gear box 6 of a transmission 4, and is disposed within PTO (power transfer off) 8. A common specification can be used for the twin differential unit, and influences by the oil variety can be avoided, assuring a given performance in any application.