A four-wheel drive vehicle are provided which enable enhancement of responsiveness to switching from a two-wheel drive state to a four-wheel drive state. A four-wheel drive vehicle includes a driving force transmission and cut-off apparatus that enables cut-off of transmission of a driving force from an engine to a propeller shaft, a driving shaft that rotates under a tuning force of the propeller shaft, a pair of hydraulic clutches and each disposed between the driving shaft and a corresponding one of rear wheels, and a control apparatus that controls a hydraulic unit that supplies hydraulic oil to the hydraulic clutches. In shifting the two-wheel drive state to the four-wheel drive state, the control apparatus controls the hydraulic unit such that a higher priority is given to supply of the hydraulic oil to first hydraulic clutch than to supply of the hydraulic oil to second hydraulic clutch.

A motor vehicle having: a prime mover; first and second groups of wheels; and a driveline operable by a controller to connect a torque transmission path from the prime mover to the wheels. The driveline connects the second group to the torque transmission path by an auxiliary portion including first and second releasable torque transmitting devices and a prop shaft. The controller operates the auxiliary portion to switch the driveline between first and second modes such that in the first mode the prop shaft is disconnected from both the torque transmission path and second group of wheels. The driveline transitions from the first mode to the second mode responsive to a value of a vehicle operating parameter, and when a transition to the second mode is made the vehicle is operable not to transition back to the first mode from the second mode before a disconnect delay period has expired.

A powertrain includes an axle end assembly rotatable about a wheel axis. A wheel bearing housing rotatably supports an outer axle end of the axle end assembly. A wheel hub is rotatably supported by the wheel bearing housing for rotation about the wheel axis. A hub actuating system is coupled to the wheel bearing housing, and is selectively controllable between an engaged state for rotatably coupling the wheel hub and the outer axle end together, and a disengaged state for de-coupling the wheel hub and the outer axle end. At least one axle bearing interconnects and rotatably supports the outer axle end relative to the actuator housing so that the outer axle end and the wheel hub are axially stacked relative to each other along the wheel axis, and the wheel hub and the outer axle end do not radially overlap each other relative to the wheel axis.

A vehicle with connectable four-wheel drive. The vehicle includes an engine with a drive shaft; a pair of main drive wheels; a main transmission line which permanently connects the drive shaft to the main drive wheels, the main transmission line including a main gearbox and a main differential; a pair of normally driven secondary drive wheels; and a connectable secondary transmission line for connecting the drive shaft also to the secondary drive wheels and having a geared transmission, at least one secondary clutch which on one side is connected to the drive shaft upstream of the main gearbox and on the other side is connected to the secondary drive wheels, and a continuously variable transmission which is controlled electronically to vary its transmission ratio in a continuous manner between two limit values without ever interrupting the transmission of the driving torque.

A vehicle with a primary driveline that is configured to distribute rotary power to a first set of vehicle wheels and a power transmitting device that can be selectively operated to transmit rotary power to a secondary driveline. The power transmitting device has an input member, which is driven by the primary driveline, and an output member that is selectively coupled to the input member to receive rotary power therefrom. The secondary driveline comprises a differential, a pair of shafts, and a side shaft coupling that selectively interrupts power transmission between the differential and one of the shafts.

A vehicle clutch control device is provided for switching from a two-wheel drive traveling to a four-wheel drive traveling. The vehicle clutch control device includes a dog clutch that separates a rear wheel drive from a front wheel drive by releasing the dog clutch, an electronically controlled coupling that distributes a driving force of a transverse engine to left and right rear wheels in accordance with a clutch connection capacity, and a four-wheel drive control unit. The four-wheel drive control unit switches the drive mode to one of a disconnect two-wheel drive mode in which the dog clutch and the electronically controlled coupling are released, a connect four-wheel drive mode in which the dog clutch and the electronically controlled coupling are engaged, and a stand-by two-wheel drive mode in which the dog clutch is engaged while the electronically controlled coupling is released.

A driving-force transmitting apparatus 1 includes first and second friction clutches, a piston that presses the first and second friction clutches, a hydraulic pump that feeds hydraulic oil to a cylinder chamber in the piston, an electric motor that drives the hydraulic pump, and a control apparatus that controls the electric motor to adjust the discharge pressure of the hydraulic pump. The control apparatus has a feedback control apparatus that controls the electric motor using a correction value based on a deviation between a target value and an actual value of the discharge pressure of the hydraulic pump, a hydraulic-oil temperature estimating apparatus that estimates a temperature of hydraulic oil, and a gain adjusting apparatus that changes a correction amount for feedback control in accordance with the estimated temperature of the hydraulic oil.

The present disclosure describes an axial coupling and methods of assembly. The assembly method can include installing an axle into a disconnect, the disconnect having a disengaged state permitting relative motion between the axle and a hub, and an engaged state preventing relative rotation between the axle and the hub. The disconnect can be mounted on a knuckle that includes a wheel-facing side and a vehicle-facing side. The disconnect can be mounted on the wheel facing side of the knuckle. The hub can be mounted to the disconnect.

A clutch control device is provided for a four-wheel drive vehicle. The clutch control device is able to suppress the elevation of the temperature of the oil supplied to a friction clutch during two-wheel drive travel when the friction clutch is released. The clutch control device includes a dog clutch and an electronic control coupling. The friction clutch is housed in a coupling case. When the dog clutch and the friction clutch are released, a two-wheel drive mode is selected. The coupling case has a passage opening that is closed to retain lubrication oil in an oil chamber with respect to a clutch chamber that houses the friction clutch. When oil stirring conditions are met thereafter, the passage opening is opened and the lubrication oil is allowed to flow into the clutch chamber from the oil chamber.

An actuator for a wheel end disconnect system includes a housing and a solenoid mounted to the housing, the solenoid is actuatable to move a plunger in a fore and aft direction. A rocker is pivotally mounted to the housing and is connected to the plunger. A shift fork slidably mounted on a translation pin extending from the housing, the shift fork including a channel for receiving an end of the rocker, wherein activation of the solenoid causes pivotal movement of the rocker to cause the shift fork to translate along the translation pin.