An off-road vehicle has front and rear wheels. An engine unit powers the wheels. The engine unit has an output shaft. A front differential is coupled with the front wheels. The front differential has a front input shaft. A front drive connects the output shaft and the front input shaft with each other. The front differential can operate in one of three modes: an unlocked mode, a locked mode and a disabled mode. A rear differential is coupled with the rear wheels. The rear differential mechanism has a rear input shaft. A rear drive connects the output shaft and the rear input shaft. The rear differential can operated in at least two modes: an unlocked mode and a locked mode. In one embodiment, the front differential is allowed to be locked only when the rear differential is locked.