An inter-axle differential assembly comprising a driving input shaft, a forward differential wheel, a rear differential wheel, a differential spider connected for common rotation with the input shaft and on which differential pinions configured to meshingly engage with said differential wheels are rotatably mounted, and a differential housing to which the differential spider is connected for common rotation. The assembly comprising an output wheel via which torque is transferable to a rear driving axle, and a connection means movable between: an open position which connects the output wheel to the rear differential wheel so that the differential housing can rotate independently of the rear differential wheel, a locking position connecting both of the differential housing and the output wheel to the rear differential wheel, and a disconnecting position connecting the differential housing to the rear differential wheel, so that the output wheel can rotate independently of the rear differential wheel.

A hybrid drivetrain is provided. The hybrid drivetrain comprises a power source, a transmission, and a tandem axle assembly. The transmission includes a primary clutch and is drivingly engaged with the power source. The tandem axle assembly includes a first axle and a second axle and is drivingly engaged with the transmission. One of the transmission and the tandem axle assembly includes a first motor generator in electrical communication with a battery. The first motor generator and the primary clutch facilitate operating the hybrid drivetrain as a hybrid drivetrain in a plurality of operating modes. The hybrid drivetrain may further comprise second and third motor generators in electrical communication with the battery to facilitate operating the hybrid drivetrain in a plurality of operating modes.

A hybrid drivetrain is provided. The hybrid drivetrain comprises a power source, a transmission, and a tandem axle assembly. The transmission includes a primary clutch and is drivingly engaged with the power source. The tandem axle assembly includes a first axle and a second axle and is drivingly engaged with the transmission. One of the transmission and the tandem axle assembly includes a first motor generator in electrical communication with a battery. The first motor generator and the primary clutch facilitate operating the hybrid drivetrain as a hybrid drivetrain in a plurality of operating modes. The hybrid drivetrain may further comprise second and third motor generators in electrical communication with the battery to facilitate operating the hybrid drivetrain in a plurality of operating modes.

An off-road utility vehicle includes a frame, an engine, a continuously variable transmission, a transaxle comprising a rear differential, an intermediate drive assembly comprising an intermediate differential, and a front drive assembly comprising a front differential. The intermediate drive assembly and transaxle are coupled via an intermediate driveshaft and the front drive assembly and the intermediate drive assembly are coupled via a front drive shaft. The front drive shaft and the intermediate drive shaft are counter rotating.

An off-road utility vehicle includes a frame, an engine, a continuously variable transmission, a transaxle comprising a rear differential, an intermediate drive assembly comprising an intermediate differential, and a front drive assembly comprising a front differential. The intermediate drive assembly and transaxle are coupled via an intermediate driveshaft and the front drive assembly and the intermediate drive assembly are coupled via a front drive shaft. The front drive shaft and the intermediate drive shaft are counter rotating.

A gear control system for controlling output torque provided to axles of a vehicle may include a first planetary gear set, a second planetary gear set, and a set of engageable locking mechanisms. Each planetary gear set may include at least a sun gear, a ring gear circumferentially disposed around the sun gear, and a carrier that is coupled to the sun gear and an axle. The set of engageable locking mechanisms may include at least one of a first engageable locking mechanism that is engageable with the first planetary gear set or a second engageable locking mechanism that is engageable with the second planetary gear set. The set of engageable locking mechanisms may be selectively configured to engage or disengage based on a trigger condition being satisfied.

A gear control system for controlling output torque provided to axles of a vehicle may include a first planetary gear set, a second planetary gear set, and a set of engageable locking mechanisms. Each planetary gear set may include at least a sun gear, a ring gear circumferentially disposed around the sun gear, and a carrier that is coupled to the sun gear and an axle. The set of engageable locking mechanisms may include at least one of a first engageable locking mechanism that is engageable with the first planetary gear set or a second engageable locking mechanism that is engageable with the second planetary gear set. The set of engageable locking mechanisms may be selectively configured to engage or disengage based on a trigger condition being satisfied.

A drive axle system having a one-way freewheel clutch. The one-way freewheel clutch is configured to transmit torque between first and second axle assembles when an interaxle differential unit is unlocked. The one-way freewheel clutch transmits torque to one of the first axle assembly and the second axle assembly when the interaxle differential unit is locked.

A drive axle system having a one-way freewheel clutch. The one-way freewheel clutch is configured to transmit torque between first and second axle assembles when an interaxle differential unit is unlocked. The one-way freewheel clutch transmits torque to one of the first axle assembly and the second axle assembly when the interaxle differential unit is locked.

Methods of controlling a tandem axle assembly in a vehicle, the tandem axle assembly including an inter-axle differential (IAD), one or more side gears, and a front tandem axle assembly having a pair of front tandem axle half shafts selectively connected to a pair of front tandem axle wheel hub assemblies. When a determined speed of the vehicle is greater or equal to a predetermined speed, the IAD may be locked, the tandem axle wheel hub assemblies may be disconnected from their respective tandem axle shafts, and/or the IAD may be moved out of engagement with the one or more side gears. When a determined speed of the vehicle is less than a predetermined speed, the IAD may be unlocked, the tandem axle wheel hub assemblies may be connected to their respective tandem axle shafts, and/or the IAD may be engaged with the one or more side gears.