A vehicle control system in a vehicle having a continuously variable transmission (CVT) system with a clutch mechanism modulates a torque capacity of the clutch mechanism. The CVT system in the vehicle further includes a primary pulley, a secondary pulley and a CVT belt for transmitting a torque to wheels from a power source rotatably connected with an input shaft. The clutch mechanism includes a forward (FWD) clutch between the power source and a CVT pulley assembly. The vehicle control system detects a wheel slip of the CVT system and controls a torque capacity of the FWD clutch, and the system is configured for avoiding a slip of the CVT belt by dissipating a spike torque generated by the wheel slip.

A vehicle includes an engine, a pair of front axle shafts, and a transfer case having a clutch assembly configured to selectively move between a closed position to enable the engine to drive the front axle shafts, and an open position to disable the engine from driving the front axle shafts. A control system is configured to momentarily open the clutch assembly when the vehicle is coming to a stop or is stopped in order to relieve residual torque build-up in the front axle shafts to thereby reduce idle vibration transmission between the engine and a body of the vehicle.

A driving force distribution control device mounted on a four-wheel drive vehicle is provided. A coupling mechanism controller connects a drive shaft with an auxiliary driving wheel and sets a fastening force as a first fastening force, when an increase rate in an accelerator opening becomes more than a given value and a vehicle speed is below a given first speed, and changes the fastening force from the first fastening force to a second fastening force, when a slip of at least one of main driving wheels is detected after the fastening force is set to the first fastening force, and before a given time period has lapsed from the setting of the fastening force, or before the vehicle speed becomes faster than a given second speed. The second fastening force at least immediately after the change of the fastening force is a value larger than the first fastening force.

A method for controlling a starting process of a vehicle includes activating a control sequence and setting a control sequence signal, defining a maximum engine drive torque, and detecting a drive request for a starting process. The method further includes, in response to the drive request, controlling a clutch-gearbox unit with an engagement process duration, controlling wheel slip of driven wheels by determining wheel speeds of the driven wheels and at least setting an output drive torque at the output shaft, and redefining the maximum engine drive torque depending on the wheel slip and a driving speed. The method also includes deactivating the control sequence and resetting the control sequence signal when limit values are reached.

A vehicle control system in a vehicle having a continuously variable transmission (CVT) system with a clutch mechanism modulates a torque capacity of the clutch mechanism. The CVT system in the vehicle further includes a primary pulley, a secondary pulley and a CVT belt for transmitting a torque to wheels from a power source rotatably connected with an input shaft. The clutch mechanism includes a forward (FWD) clutch between the power source and a CVT pulley assembly. The vehicle control system detects a wheel slip of the CVT system and controls a torque capacity of the FWD clutch, and the system is configured for avoiding a slip of the CVT belt by dissipating a spike torque generated by the wheel slip.

A four-wheel-drive vehicle includes: a pump that is actuated by an electric motor; a friction clutch that has a plurality of clutch plates that are pressed by a piston that is movable by working oil discharged from the pump; a control device that controls the electric motor; front wheels, to which a drive force of an engine is always transferred; and rear wheels, to which the drive force of the engine is transferred in accordance with the fastening force of the friction clutch. When it is determined that the vehicle is in a high fastening force-requiring state in which it is necessary for the friction clutch to transfer a large drive force temporarily, the control device causes the electric motor to output torque that is larger than torque that the electric motor can continuously output.

A multi-axle drive device and method for operating a multi-axle drive device. The multi-axle drive device is provided with a synchronization clutch present in an operational connection between a first output shaft and a connecting shaft and at least one disconnecting clutch present in an operational connection between the connecting shaft and a second output shaft. The synchronization clutch and the disconnecting clutch are opened in a first operating state and closed in a second operating state. At the same time, with an intended change from the second operating state to the first operating state, the synchronization clutch is maintained at least partially opened and the separation clutch is maintained closed, so that, when a first operating mode is carried out, the disconnecting clutch is opened, and when a second operating mode is carried out, the synchronization clutch is closed again.

A system and method of controlling engine clutch engagement during TCS operation of a hybrid vehicle are provided. The method includes determining whether a TCS is operating and upon determining that the TCS is operating, determining a compensation value for early engagement of an engine clutch during the TCS operation based on a difference between a front wheel speed and a rear wheel speed and a slip amount of front wheels. Additionally, the method includes determining whether engagement of the engine clutch is capable of being started based on the compensation value and starting the engine clutch engagement. Since the engagement of the engine clutch is controlled based on the speed of non-drive wheels during TCS operation, the engagement stability of the engine clutch is improved and the amount of time required to engage the engine clutch is decreased.

A method for operating a drivetrain for a motor vehicle, said method includes: reducing a transmission torque transmitted between a primary drive axle operatively connected with a secondary drive axle of the motor vehicle via a clutch configured to allow adjustment of the transmission torque when determining at the secondary drive axle a wheel slip which exceeds a defined slip threshold value.

A four-wheel-drive vehicle includes: a pump that is actuated by an electric motor; a friction clutch that has a plurality of clutch plates that are pressed by a piston that is movable by working oil discharged from the pump; a control device that controls the electric motor; front wheels, to which a drive force of an engine is always transferred; and rear wheels, to which the drive force of the engine is transferred in accordance with the fastening force of the friction clutch. When it is determined that the vehicle is in a high fastening force-requiring state in which it is necessary for the friction clutch to transfer a large drive force temporarily, the control device causes the electric motor to output torque that is larger than torque that the electric motor can continuously output.