Abstract: Systems and methods of controlling a clutch in a hybrid vehicle with a manual transmission, are provided. With the goal of enabling autonomous/assisted clutch control in a hybrid vehicle, while preserving the familiar mechanical feeling at the clutch pedal that driving enthusiasts prefer, embodiments of the disclosed technology use a shuttle valve to blend control of clutch engagement between a driver and an ECU. In these embodiments, a clutch pedal in the vehicle may be mechanically connected to a piston in a first hydraulic cylinder (just like in a traditional mechanical/hydraulic clutch actuation system), and an ECU may actuate a second hydraulic cylinder. Accordingly, a shuttle valve may be used to route the fluid coming from the cylinder with the greater pressure (i.e. the driver actuated cylinder or the ECU actuated cylinder), to a third hydraulic cylinder which adjusts engagement of a clutch by a mechanical linkage.

Abstract: A differential case (23) is therein provided with a plurality of rotating discs (38) that are spline coupled to an outer peripheral side of a right side gear (35), and a plurality of non-rotating discs (39) that are arranged between the respective rotating discs (38). A pressure ring (43) is disposed between a right retainer (41) and the rotating disc (38). The right retainer (41) is provided with a piston (46) that applies a load to the pressure ring (43) to bring the rotating discs (38) and the non-rotating discs (39) into frictional contact. A lever member (53) is disposed between the differential case (23), the right side gear (35) and the pressure ring (43). The lever member (53) transmits a reaction force due to the engagement between the pinion gear (33) and the right side gear (35) to the pressure ring (43) to control a load to be applied to the pressure ring (43) from the piston (46).

Abstract: A differential device includes a differential case, a first output gear and a second output gear, and an interrupting mechanism. The differential case is rotatable. A drive force can be input to the differential case. The first output gear and the second output gear are accommodated in the differential case. The first output gear and a second output are rotatable with respect to the differential case and output the drive force received from the differential case. The interrupting mechanism is disposed on a side of the first output gear and connects and disconnects power transmission between the differential case and the first output gear. The first output gear is coupled to an output shaft through an intermediate member.

Abstract: The disclosure relates to a differential of a motor vehicle, comprising a crown wheel and a differential casing connected thereto. The differential further comprises differential pinion gears arranged on differential pins, wherein the differential pins are connected to the differential casing. The differential comprises a first differential side gear, which is mounted on a first drive shaft for conjoint rotation, and a second differential side gear, which is mounted on a second drive shaft for conjoint rotation. The differential comprises a first plate stack, which is arranged axially with respect to the first drive shaft between the crown wheel and the first differential side gear, and a second plate stack, which is arranged axially with respect to the second drive shaft between the crown wheel and the differential casing. Force can be applied to one or both of the plate stacks by a switchable actuating device counter to the differential side gear associated with the particular plate stack.

Abstract: An actuator is used to longitudinally move a spline sleeve for controlling drive mode of a differential on an off-road vehicle. The actuator's motor rotates an eccentric knob through a drive train including intermediate gears and a worm gear. The eccentic knob is linked to the spline sleeve through a torsion spring carried on a pivot plate, with legs of the torsion spring pushing a slide block, transferring a moment provided by the eccentric knob into a linear slide force. The pivot plate and torsion spring are jointly mounted on the actuator housing by a hub, opposite the rotational axis of the eccentric knob from the slide block. The slide block includes a contact which completes a circuit through conductive pads on the actuator housing, so the position of the slide block can be directly sensed.

Abstract: A shift module (1) for a differential lock (7), a shift gearbox or an axle connection. The shift module has a shift sleeve (2) and a shift piston (4) which is designed as a ring piston (4). The shift module is mounted in one of a respective differential lock, a respective distribution gearbox, and a respective axle connection.

Abstract: A drive switching mechanism of a utility vehicle includes: a two-wheel drive and four-wheel drive switching device that switches between two-wheel drive and four-wheel drive of the utility vehicle; and a control unit that controls the drive switching mechanism. The two-wheel drive and four-wheel drive switching device switches between two-wheel drive and four-wheel drive by using a first clutch. The control unit permits the two-wheel drive and four-wheel drive switching device to switch from two-wheel drive to four-wheel drive when a rotation difference of the first clutch becomes equal to or smaller than a predetermined value.

Abstract: A driving force distribution apparatus includes a driving force connecting/disconnecting mechanism between a pinion gear shaft and an intermediate rotational member, a first driving force adjustment mechanism between the intermediate rotational member and a second output rotational member, a second driving force adjustment mechanism between the intermediate rotational member and a first output rotational member, and a hydraulic unit configured to generate pressures of hydraulic oil for operating the driving force connecting/disconnecting mechanism and the first and second driving force adjustment mechanisms. The hydraulic unit includes a single hydraulic pump and a hydraulic circuit configured to distribute a pressure of the hydraulic oil, which is discharged from the hydraulic pump, to cylinder chambers of pistons.

Abstract: The present specification discloses a differential mechanism and a vehicle. The differential mechanism includes a shell. A left half axle gear, a right half axle gear, a planet wheel and a planet wheel axle are disposed in the shell. The planet wheel is rotatably mounted on the planet wheel axle and meshes with the left half axle gear and the right half axle gear. A power engagement device includes a first engagement portion and a second engagement portion. The first engagement portion is connected with the left half axle gear or the right half axle gear, and the second engagement portion rotates synchronously with and moves axially relative to the shell. An engagement portion drive device includes a drive pin and a drive portion. The drive portion is configured to drive the drive pin to drive the second engagement portion close to the first engagement portion along an axial direction.

Abstract: A method of providing limited slip in a differential assembly includes interconnecting an axle and a differential assembly through a first slippable linkage. The axle is driven in rotation with a first housing of the differential assembly operable to be driven in rotation by a ring gear. A plurality of pinion gears of the differential assembly are positioned in the first housing and are driven in rotation by the first housing. A side gear is fixed to the axle and is meshed with at least some of the pinion gears. The axle is operable to slip relative to the first housing. The first housing, the plurality of pinion gears and the side gear are enclosed within a second housing. The axle extends from a first end positioned within both of the first housing and the second housing to a second end positioned outside of both of the first housing and the second housing.

Abstract: A wheel speed sensor system for determining the rotational speed of the wheels mounted at the opposite ends of an axle without requiring wheel speed sensor assemblies for each wheel shaft axle. As a result, the speed sensor system of the present disclosure can be housed in small sized or small capacity axle housing such as banjo type housings. In one embodiment, a wheel speed sensor assembly is positioned in the axle housing to determine the speed of one of the wheel axle shafts and a differential speed sensor assembly is positioned in the axle housing to determine the rotational speed of the differential. With these two speed measurements the rotational speed of the other wheel axle shaft can be calculated by a control unit. The wheel and differential speed sensor assemblies can each include a toothed or slotted ring or disk and sensor for sensing the teeth.

Abstract: An axle assembly having a countershaft. The countershaft may be disposed in an axle housing. An axle shaft may be disposed in the countershaft. A first clutch may control rotation of the countershaft with respect to the axle shaft. A second clutch may control rotation of the countershaft with respect to the axle housing.

Abstract: A differential assembly for a vehicle includes a drive train for transferring motive power from an engine drive member to the right and left drive shafts which are coupled, respectively, to ground engaging members of the vehicle. The drive train includes a rotating element operatively engaged to the drive member and to the right and left drive shafts. The differential assembly further includes a first speed sensor is arranged to measure rotational speed of (i) the rotating element or (ii) one of the right and left drive shafts, and a second speed sensor arranged to measure rotational speed of one of the right and left drive shafts. The second speed sensor arranged to measure rotational speed of the other of the right and left drive shafts when the first speed sensor is arranged to measure rotational speed of one of the right and left drive shafts.

Abstract: A differential and method of operating the differential is described. The differential has side gears and at least one pinion gear in mesh with the side gears. One of the side gears is provided with dog clutch teeth and an axially extending ring carrying clutch plates. A clutch housing has an axially extending ring carrying clutch plates interleaved with the side gear clutch plates. A dog clutch ring is connected to the clutch housing and selectively engages with the side gear dog clutch teeth. The above-described system permits an axle system of a tandem axle system to be selectively engaged and disengaged.

Abstract: A hybrid powertrain unit comprises an engine and a gearbox with a primary shaft connectable to an engine shaft via a clutch and a secondary shaft with an output pinion meshing with a first differential crown wheel. An electric machine is configured to function as an electric motor and generator, having a shaft connected by a transmission to a second differential crown wheel. The transmission, arranged between the electric machine shaft and the second crown wheel includes a first engagement device. The electric machine shaft is connected to the engine shaft by a belt transmission including a belt engaged on a first pulley connected to the electric machine shaft and a second pulley connected to the engine shaft. Between the electric machine shaft and said first pulley is a second engagement device. The engagement devices are arranged coaxially with the electric machine shaft on opposite sides of the electric machine.

Abstract: A power switching device includes a power transmission unit and a driving unit. The transmission unit includes a differential, an axle aligned with the differential, and a coupler sleeved movably on one of the differential and the axle. The driving unit includes a controller, a first transmission mechanism driven by the controller, and a second transmission mechanism driven by the first transmission mechanism. The controller is a solenoid or an electric actuator, and is operable to activate the second transmission mechanism. The coupler can be moved by the second transmission mechanism to interconnect the differential and the axle, so as to allow for co-rotation of the axle with the differential.

Abstract: A disconnectable all-wheel drive system for motor vehicles having a multi-speed power take-off unit and a multi-speed rear drive module.

Abstract: A rear drive module for an all-wheel drive vehicle. The rear drive module includes a disconnect clutch, a differential assembly and a hollow shaft. The disconnect clutch has a first clutch member, which is coupled to the spool for rotation therewith, and a second clutch member. The differential assembly includes a differential case. The hollow shaft is coupled to the differential case for rotation therewith and is configured to transmit rotary power in a power path between the disconnect clutch and the differential assembly.

Abstract: A method for operating a transmission device (1), which is transferable into different operating states through the actuation of shifting elements (A to F), is described. At least one of the shifting elements (A, F) is designed as a positive-locking shifting element, which is supplied with operating pressure (p_sys) for presenting a defined operating state of the transmission device (1). Through a sensor device upstream of a valve device, which is connected to a transmission area essentially featuring ambient pressure, a value of a pressure signal corresponding to the operating pressure can be determined. Upon exceeding a threshold value of the pressure signal, currently in the area of the positive-locking shifting element (A, F), a change in operating state is determined, and, upon falling short of an additional threshold value of the pressure signal, the reaching of the requested operating state is established.

Abstract: A differential gear mechanism can include a differential casing, a piston and an externally mounted plenum assembly. The differential casing can have a differential gear set configured to selectively rotate a first axle shaft and a second axle shaft. The piston can be slidably disposed in the differential casing and configured to actuate a clutch assembly. The externally mounted plenum assembly can include a plenum assembly housing, a hydraulic coupling and a motor mounted on the plenum assembly housing. The plenum assembly housing can define an axle opening configured to receive one of the first and second axle shafts therethrough. The hydraulic coupling can be arranged on the plenum assembly housing at the axle opening. The motor can be configured to pump hydraulic fluid from the externally mounted plenum assembly, through the hydraulic coupling and into the differential casing to act onto the piston.

Abstract: An axle assembly having an axle housing assembly having a carrier housing and first and second end caps that are mounted to the carrier housing. The first end cap cooperates with the carrier housing to define a differential cavity for receipt of a differential assembly, while the second end cap cooperates with the carrier housing to define a clutch cavity for receipt of a clutch. A spindle drivingly couples a first output of the differential with an input of the clutch member. A first output member is coupled for rotation with a second output of the differential and a second output member is coupled for rotation with an output of the clutch. The spindle is received through a tubular portion of carrier housing.

Abstract: A method and system for bypassing a control valve that would otherwise disengage differential and/or inter-axle locking means. The bypass is achieved by a valve that can be actuated by a vehicle condition change.

Abstract: In a driveline in a front wheel drive vehicle the distribution of drive torque to the drive wheels (1) via a differential (6) is controlled by means of a differential brake with a hydraulically controlled limited slip clutch (7). A low preparatory hydraulic pressure is applied to the clutch at the occurrence of any one of certain predetermined driving situations for decreasing the response time for the clutch.

Abstract: A hydraulic bulkhead configured for use with a limited slip differential includes a plenum comprising a passageway for hydraulic fluid and a boss. A first seal is located on an outer surface of the boss. The outer surface of the boss is a low pressure area relative to the inner surface of the boss. The plenum is stationary relative to the limited slip differential. A differential assembly including the inventive hydraulic bulkhead is also disclosed.

Abstract: A control system or method for a vehicle references a camera and sensors to determine when an offset of a yaw rate sensor may be updated. The sensors may include a longitudinal accelerometer, a transmission sensor, a vehicle speed sensor, and a steering angle sensor. The offset of the yaw rate sensor may be updated when the vehicle is determined to be stationary by referencing at least a derivative of an acceleration from the longitudinal accelerometer. The offset of the yaw rate sensor may be updated when the vehicle is determined to be moving straight by referencing at least image data captured by the camera. Lane delimiters may be detected in the captured image data and evaluated to determine a level of confidence in the straight movement. When the offset of the yaw rate sensor is to be updated, a ratio of new offset to old offset may be used.

Abstract: A transmission system is provided having an input member, an output member, four planetary gear sets, a plurality of coupling members a plurality of torque transmitting devices, a launch clutch, and a hydraulic circuit. Each of the planetary gear sets includes first, second and third members. The torque transmitting devices may include clutches and brakes.

Abstract: A traction control system and methodology that utilize a phase-out and phase-in of maximum drive torque and/or a regenerative brake torque based on vehicle speed and road slope.

Abstract: A range determination apparatus for preventing a shift range from being undefined during speed change states of an automatic transmission with no manual valve. The range determination apparatus includes a gear speed change mechanism and a plurality of friction engagement elements operative to have respective operation states changed between an engagement and a disengagement state. The range determination apparatus is used for automatic transmissions subject to speed changes via a torque transmission path of the gear speed change mechanism changed by the operation states of the friction engagement elements. A real shift range determination is carried out on the basis of the operation states of the friction engagement elements, where a T-ECU is operative to determine a current shift range based on detection results obtained by oil pressure sensors and operation patterns preliminarily memorized when the operation states of the friction engagement elements are not being changed.

Abstract: A drive system includes a differential for transmitting power between a power source and first axles; a clutch including a first member driveably connected to the power source and a second member secured to a power transfer shaft; and a servo including a cylinder connected to a pressure source, a piston displaceable in the cylinder for mutually disconnecting the first and second members and allowing mutual engagement of the first and second members.

Abstract: A powertrain includes a transmission coupled to a driveline. A method for monitoring torque of the driveline includes monitoring signals from first and second rotational sensors located at respective first and second rotationally-coupled positions of the driveline separated by a distance along the driveline, determining rotation of the driveline at the first and second rotationally-coupled positions from said signals, determining a twist angle derived from a difference between the rotations of the driveline at the first and second rotationally-coupled positions, calculating a driveline torque corresponding to the twist angle, and controlling operation of the powertrain in response to the driveline torque.

Abstract: A differential axle assembly for a work machine having a differential lock capability. The differential axle has a differential gear housing, which utilizes a sealed housing on the outside thereof and a bleed flow path for pressurized liquid lubricant actuating a differential lock feature to provide adequate cooling flow for the differential gear set and differential lock mechanism under heavy duty circumstances.

Abstract: A drive system includes a rotating power source, a planetary differential including a ring gear engaged with the power source, a sun gear secured to a first shaft and a carrier secured to a second shaft, a member secured to an output shaft, and a coupler alternately connecting and disconnecting the member and the ring gear.

Abstract: A hydraulic system for a vehicle drivetrain includes a torque transfer device having a first actuator that actuates to selectively communicate rotatable motion from an input member to an output member. A limited slip differential selectively transfers drive torque from the output member to at least one of the first and second axle shafts. A motor drives a first and a second output shaft. A first pump is rotatably driven by the first output shaft. The first pump selectively supplies the hydraulic fluid to the first actuator. A second pump is rotatably driven by the second output shaft. The second pump selectively supplies the hydraulic fluid to the second actuator.

Abstract: A method for actuating a clutch in the drive train of a motor vehicle, including: generating a respective position setpoint for each predetermined target interval to actuate the clutch; in each predetermined target interval, actuating the clutch in a plurality of predetermined controller sampling intervals; discretizing a respective position setpoint change into a plurality of intermediate position setpoints; determining a number of intermediate position setpoints in the plurality of intermediate position setpoint depending on the ratio of the target interval to the controller sampling interval; and specifying the respective position setpoint changes in steps to actuate the clutch.

Abstract: A method for operating a vehicle drive train comprising a drive unit, a transmission, and an all-wheel splitter having a clutch. The all-wheel splitter is positioned between the transmission and the output and splits a transmission output torque to vary the torque distribution to driven axles of the output. The split of the output torque to the driven axles is performed by a control unit in such a way that the transmission output torque, less a predetermined nominal torque set by the all-wheel drive strategy, is transferred to a first axle while the nominal torque is transferred to a second axle. When defined operating conditions are met, a clutch monitoring function is activated and the nominal torque is replaced by a torque definition of the clutch monitoring function so that the torque which is transferred by clutch to the second driven axle, is increased, then kept constant, and thereafter reduced.

Abstract: An engine-propelled monowheel vehicle comprises two wheels, close together, that circumscribe the remainder of the vehicle. When the vehicle is moving forward, the closely spaced wheels act as a single wheel, and the vehicle turns by leaning the wheels. A single propulsion system provides a drive torque that is shared by the two wheels. A separate steering torque, provided by a steering motor, is added to one wheel while being subtracted from the other wheel, enabling the wheels to rotate in opposite directions for turning the vehicle at zero forward velocity. The vehicle employs attitude sensors, for sensing roll, pitch, and yaw, and an automatic balancing system. A flywheel in the vehicle spins at a high rate around a spin axis, wherein the spin axis is rotatable with respect to the vehicle's frame. The axis angle and flywheel spin speed are continually adjustable to generate torques for automatic balancing.

Abstract: A driving force controlling apparatus includes a driving force controller configured to determine a state of a road surface. A driving force controller is configured to control a driving force of a vehicle based on the road surface state. A rear-wheel speed sensor is configured to detect a rear-wheel speed. A low-friction-coefficient road surface determining device is configured to determine whether the road surface is a low-friction-coefficient road surface using the rear-wheel speed on a predetermined condition. A determination prohibition device is configured to prohibit the low-friction-coefficient road surface determining device from determining whether the road surface is a low-friction-coefficient road surface, if (a) the rear-wheel speed sensor is abnormal, or if (b) a predetermined time has elapsed from when a shift range is changed from a reverse range to a drive range and/or (c) a gear position has become greater than or equal to a predetermined gear position.

Abstract: A vehicle drivetrain can include various structures, such as a multi-ratio transmission, a two-speed final drive assembly connected in series with the multi-ratio transmission and including a low speed final drive ratio and a high speed final drive ratio, a pair of front driveshafts driven by the two-speed final drive assembly, a pair of rear driveshafts, a rear differential assembly connected to the two-speed final drive assembly, and a control assembly including. The control assembly can include a controller in electrical communication with portions of the rear differential assembly, such as a variable displacement pump and purge valve. An input array can be in electrical communication with the controller and can include a plurality of sensors, and at least one switch accessible to an operator of the vehicle. Various related methods can also be executed for control and operation of such a drivetrain.

Abstract: A drive system includes a rotating power source, a planetary differential including a ring gear engaged with the power source, a sun gear secured to a first shaft and a carrier secured to a second shaft, a member secured to an output shaft, and a coupler alternately connecting and disconnecting the member and the ring gear.

Abstract: A vehicle drive train for transferring torque to first and second sets of wheels includes a first driveline adapted to transfer torque to the first set of wheels and a first power disconnection device. A second driveline is adapted to transfer torque to the second set of wheels and includes a second power disconnection device. A hypoid gearset is positioned within one of the first driveline and the second driveline in a power path between the first and second power disconnection devices. The hypoid gearset is selectively disconnected from being driven by the first driveline and the second driveline when the first and second power disconnection devices are operated in a disconnected, non-torque transferring, mode. At least one of the first and second power disconnection devices includes an active dry friction clutch.

Abstract: A transfer case includes an input shaft, first and second output shafts, and a planetary gearset including a sun gear, a ring gear and planet gears rotatably supported on a carrier coupled to the first output shaft. A collar is driven by the sun gear and selectively drives the carrier. The ring gear is moveable between first and second positions. The collar is coupled to the ring gear for movement therewith between first and second positions. The collar is operable in its first position to couple the sun gear to the carrier and operable in its second position to be released from engagement with the carrier. The ring gear is operable in its first position to be released from coupled engagement with a stationary member and operable in its second position to be coupled to the stationary member. A mechanism moves the ring gear between its first and second positions.

Abstract: A hydraulic bulkhead configured for use with a limited slip differential includes a plenum comprising a passageway for hydraulic fluid and a boss. A first seal is located on an outer surface of the boss. The outer surface of the boss is a low pressure area relative to the inner surface of the boss. The plenum is stationary relative to the limited slip differential. A differential assembly including the inventive hydraulic bulkhead is also disclosed.

Abstract: A torque vectoring device directs different torques at will to the two wheels of a drive axle on a road vehicle. It has two hydraulically controlled disc clutches, connected to a drive shaft, extending through the device, and in engaged condition intended for connecting the drive shaft to either of two gear sleeves, each in splines engagement with an eccentric tube eccentrically journaled in relation to the drive shaft, and a torque transmitting mechanism with a gear ratio of 1:1 between the eccentric tube and a differential case sleeve, coaxial with the drive shaft and forming part of a differential case of a differential on the drive axle, to which differential the torque vectoring device is connected.

Abstract: A power transmission device includes a housing, a rotatable input member and a rotatable output member supported in the housing by a pair of bearings. A friction clutch is operable to selectively transmit a requested magnitude of torque between the input member and the output member. The clutch is axially positioned between the bearings. An actuator is operable to provide an actuation force to the friction clutch to generate the requested magnitude of torque.

Abstract: A hydraulic system for a vehicle clutch assembly can include an on-demand variable displacement pump and a purge valve for regulating hydraulic pressure supplied to the clutch(es). The hydraulic pressure at the pump can have multiple displacement settings to compensate for variable changes in clutch pressure requirements. The purge valve can be configured to purge hydraulic pressure from the hydraulic system so that an optimum, controllable, and/or pre-determined operating pressure can be supplied to the clutch(es). The system can be configured to provide accurate control of clutch(es) when a drivetrain is being automatically controlled to switch between a low gear ratio and a high gear ratio.

Abstract: A power transfer device for a front wheel drive motor vehicle includes an input shaft driven by a power source, a second shaft driven by the first shaft through one of a plurality of speed gearsets, an output gearset driven by the second shaft and a differential assembly. The differential assembly includes an electronically controlled, hydraulically actuated, clutch operable to place the differential assembly in one of an open mode, a locked mode and a limited slip mode. A clutch actuator includes an electric motor coupled to a pump where the pump provides pressurized fluid to the clutch to operate the clutch in one of the locked and limited slip modes.

Abstract: A differential system for a front wheel drive vehicle. The differential system includes a differential carrier (24), an actuator housing {44), an intermediate shaft (32), a clutch pack (42), and a piston (40). The differential carrier (24) houses a differential assembly (16) configured to drive a right and left axle shaft. The actuator housing (44) is configured to rotate in conjunction with the differential carrier (24). The intermediate shaft (32) extends through the actuator housing (44). The clutch pack (42) has a first set of clutch plates (46) that engage the actuator housing (44} and a second set of clutch plates (48) that engage the intermediate shaft (32). The piston (40) compresses the first and second set of clutch plates {46, 48) thereby frictionaiiy coupling the differential carrier (24) to the intermediate shaft (32) and thus locking or modulating the differential.

Abstract: A rear-drive vehicle having a self-locking differential; a regulating device for regulating the lock percentage of the differential; a number of sensors for real-time detecting dynamic parameters of the vehicle; and a central control unit for controlling the regulating device to regulate the lock percentage of the differential as a function of the dynamic parameters of the vehicle.

Abstract: An air actuated shift mechanism is housed within a drive axle housing and can be used to actuate a two-speed shifter, or it can be used to actuate a differential locking mechanism. The air actuated shift mechanism includes a lock member and an engageable member that is selectively engaged by the lock member. When the lock member and engageable member are in an engaged position, a first axle function is provided such as a low speed or a locked differential condition. When the lock member and the engageable member are in a disengaged position, a second axle function is provided such as a high speed or an unlocked differential condition. A shift member moves one of the lock member and the engageable member to provide the engaged position, and an air actuated piston controls movement of the shift member.

Abstract: A drive system designed to use a vehicle's existing hydraulic system to operate a controllable limited slip differential assembly. The limited slip differential assembly may be associated with the front axle, the rear axle, or the driveline between the front and rear axles. The differential assembly may also be used in combination that includes front, rear, or intermediate differential assemblies. The drive system further includes a friction clutch assembly for selectively engaging and disengaging an input member with an output member of the differential assembly, a fluid clutch actuator for selectively frictionally and variably loading the clutch assembly, and a fluid pump that is a common source of pressurized fluid for the fluid clutch actuator and the existing hydraulic system of the motor vehicle other than the fluid clutch actuator of the drive system. The fluid clutch actuator is actuated by fluid pressure generated by the fluid pump.