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.

The present disclosure relates to a limited-slip clutch system and method. In one aspect, the limited-slip clutch actuation system can include a hydraulic pump operated by a variable speed drive wherein the pump can be configured to generate hydraulic flow in a hydraulic circuit including an actuation branch line that actuates a clutch. The circuit may also include a flow regulating valve for regulating a hydraulic fluid flow rate through the hydraulic circuit wherein the flow regulating valve can be configured to prevent the hydraulic fluid flow rate from exceeding a set maximum flow rate regardless of a magnitude of the hydraulic pressure in the hydraulic circuit. In operation, the pump speed can be controlled based on a command pressure set point and the measured pressure in the actuation branch line and to minimize operational costs by operating the pump at a transition region of the system pressure-pump speed curve.

A modular electronic control system for a differential is described. Such a control system can contain an actuator and sensor in the differential casing and a connection between these elements in the differential casing and a controller outside the differential. The controller can be in the form of a printed circuit board residing in a control housing attached to the differential casing. In alternative embodiments, the controller may also be more distally located in the vehicle, where the controller housing contains means for conducting electrical signals from the interior of the differential casing to the vehicle without containing a printed circuit board. The controller may also contain a thermally conductive portion for dissipating heat generated by the controller.

Methods and systems for a locking mechanism in an inter-axle differential are provided. A vehicle system, in one example, includes an electric motor coupled to a clutch assembly in a locking mechanism of an inter-axle differential coupled to a first axle and a second axle, the clutch assembly is configured to selectively disengage the locking mechanism, and in the disengaged configuration the locking mechanism permits speed differentiation between the first and second axles. The system further includes an electric motor brake coupled to the electric motor and configured to selectively apply a brake torque to the electric motor and the electric motor is configured to actuate the clutch assembly.

A bi-directional overrunning clutch differential is configured to transmit power from an input shaft to a first output shaft and a second output shaft in a vehicle. The differential includes a differential housing having a first bearing seat and a second bearing seat. A first bearing is carried by the differential housing in the first bearing seat, and a second bearing is carried by the differential housing in the second bearing seat. A first retaining ring secures the first bearing in the first bearing seat, and a second retaining ring secures the second bearing in the second bearing seat. A first output hub is carried by the first bearing for rotation relative to the differential housing, and a second output hub is carried by the second bearing for rotation relative to the differential housing.

A drive control apparatus includes a circuitry configured to operate a differential lock device of a differential device in timings which are different between a two wheel drive state and a four wheel drive state. The differential device is disposed between one of a pair of front wheels and a pair of rear wheels of the vehicle and configured to transmit a driving force from a drive source to the one of the pair of front wheels and the pair of rear wheels. The differential lock device is configured to lock a differential rotation of a pair of output members of the differential device that are differentially rotatable with respect to each other, and configured to respectively output the drive force.

Methods and systems for operating axles of a vehicle are provided. In one example, an apparatus is configured to consume a first amount of electric power to indicate a first axle operating state. The apparatus is also configured to consume a second amount of electric power to indicate a second axle operating state.

A differential actuator including: a shuttle supported for rotation around a central axis and including a body portion, a first pinion gear connected to the body portion, and a second pinion gear connected to the body portion; a first component including a first plurality of teeth meshed with the first pinion gear and supported for rotation around the central axis; and a second component including a second plurality of teeth meshed with the second pinion gear and supported for rotation around the central axis. For a first operating mode of the differential actuator: the shuttle is arranged to be rotated by an actuator in a first circumferential direction around the central axis; and the first pinion gear is arranged to rotate the first component in the first circumferential direction around the central axis.

Methods and systems for a differential assembly are provided herein. In one example, a diagnostic method includes generating a clutch fault according to a variance between an initial engagement position and a lock point position of a clutch motor that occur during engagement of an interaxle differential (IAD) locking clutch coupled to the clutch motor. In the IAD system, an actuation assembly is coupled to the clutch motor and the IAD locking clutch.

An electronically locking differential assembly according to the present disclosure includes a differential case, a first and second side gear, a lock actuation mechanism, a first and second tone wheel, a first and second pickup sensor and a controller. The lock actuation mechanism includes a ramp plate that selectively moves between a locked state and an unlocked state. The first tone wheel has a first plurality of teeth formed on the differential case. The second tone wheel has a second plurality of teeth formed on the ramp plate. The first pickup sensor senses a position of the first plurality of teeth. The second pickup sensor senses a position of the second plurality of teeth. The controller determines whether the lock actuation mechanism is in the locked or unlocked state based on the respective positions of the first and second plurality of teeth.