Abstract: A method of controlling a fluid level around a transmission gear of a vehicle includes the steps of providing a set of predetermined operating conditions, each predetermined operating condition having a corresponding predetermined fluid level requirement, operating the vehicle at an actual operating condition, determining a predetermined operating condition equivalent to the actual operating condition, and arranging the fluid level around the transmission gear to be equivalent to the predetermined fluid level requirement corresponding to the predetermined operating condition.

Abstract: An actuator for a tire inflation system, the actuator having a first component that has a first fluid passage and a second component having a second fluid passage and a sealing surface for sealing engagement with a rotatable component of a wheel assembly. The second component is movable relative to the first component between a first position, in which the first fluid passage is isolated from the second fluid passage and the sealing surface is spaced from the rotatable component, and a second position, in which the first fluid passage is in fluid communication with the second fluid passage and the sealing surface is in sealing engagement with a rotatable component.

Abstract: An actuator for a tire inflation system, the actuator having a first component that has a first fluid passage and a second component having a second fluid passage and a sealing surface for sealing engagement with a rotatable component of a wheel assembly. The second component is movable relative to the first component between a first position, in which the first fluid passage is isolated from the second fluid passage and the sealing surface is spaced from the rotatable component, and a second position, in which the first fluid passage is in fluid communication with the second fluid passage and the sealing surface is in sealing engagement with a rotatable component.

Abstract: A drive unit assembly including an input element, a first output element, a second output element and a drive unit housing containing a differential unit, the differential unit drivingly coupling the input element, the first output element and the second output element, the input element having input coupling features positioned externally of the drive unit housing, the first output element having output coupling features positioned externally of the drive unit housing, wherein the drive unit housing includes at least one mounting feature for securing the drive unit housing externally relative to an axle assembly and the second output element is suitable for driving an axle assembly.

Abstract: A transmission system includes a housing having a sump, the housing containing a crown wheel and a pinion. The transmission system further includes an oil reservoir and a pump selectively operable to pump fluid from the oil reservoir to the sump for lubricating the crown wheel. The pump is selectively operable to pump fluid from the sump to the reservoir.

Abstract: An axle assembly including a housing having a first axle tube and a second axle tube, a crown wheel mounted in the housing, a pinion in meshing engagement with the crown wheel, a first reservoir for retaining fluid in contact with the crown wheel for lubricating the crown wheel, a second reservoir for retaining fluid remote from the crown wheel, a first system for transferring fluid in the first reservoir to the second reservoir, a second system for transferring fluid in the second reservoir to the first reservoir, a sensor for generating a signal representative of an axle assembly characteristic, the axle assembly further including a control system for receiving said signal and operating said first system and or said second system to transfer fluid to or from the first reservoir in response to said signal.

Abstract: An axle assembly having two hubs, each for connection to a wheel, a housing for differential gears and a mounting arrangement for a braking system for braking a connected wheel. The housing has a depression formed therein. The depression is configured so as to accommodate: (a) when the mounting arrangement has a drum brake mounted thereon, movement of a slack adjuster of the drum brake in a direction away from one of the hubs nearest the drum brake so as to allow detachment of the slack adjuster; and/or (b) when the mounting arrangement has a disc brake mounted thereon, an air chamber of the braking system, wherein the air chamber is capable of being partially accommodated within the depression.

Abstract: A drive unit assembly including an input element, a first output element, a second output element and a drive unit housing containing a differential unit, the differential unit drivingly coupling the input element, the first output element and the second output element, the input element having input coupling features positioned externally of the drive unit housing, the first output element having output coupling features positioned externally of the drive unit housing, wherein the drive unit housing includes at least one mounting feature for securing the drive unit housing externally relative to an axle assembly and the second output element is suitable for driving an axle assembly.

Abstract: An axle assembly including a housing having a first axle tube and a second axle tube, a crown wheel mounted in the housing, a pinion in meshing engagement with the crown wheel, a first reservoir for retaining fluid in contact with the crown wheel for lubricating the crown wheel, a second reservoir for retaining fluid remote from the crown wheel, a first system for transferring fluid in the first reservoir to the second reservoir, a second system for transferring fluid in the second reservoir to the first reservoir, a sensor for generating a signal representative of an axle assembly characteristic, the axle assembly further including a control system for receiving said signal and operating said first system and or said second system to transfer fluid to or from the first reservoir in response to said signal.

Abstract: A braking apparatus for a vehicle, in particular a heavy goods vehicle, includes a drive axle having a transmission gear, such as a differential, around which an amount of oil for lubrication is variable. The brake apparatus further includes at least one friction brake and at least one retarder that is capable of operating to slow the vehicle through the transmission gear. The braking apparatus comprises a brake operating device for operating the at least one friction brake and the least one retarder, and a determining feature to determine an oil level around the transmission gear. The brake operating device, on operation by a user, is arranged to apply the retarder when the oil level around the transmission gear is above a threshold level, and, if the oil level is below the threshold level, the brake operating device is arranged to initiate an increase in the oil level around the transmission gear.

Abstract: A drive axle assembly that may include an input shaft, an intermediate shaft, an output shaft, and an actuator unit. The actuator unit may move the intermediate shaft between a first position in which the intermediate shaft transmits torque to the output shaft and a second position in which the intermediate shaft does not transmit torque to the output shaft.

Abstract: A transmission system includes a housing having a sump, the housing containing a crown wheel and a pinion. The transmission system further includes an oil reservoir and a pump selectively operable to pump fluid from the oil reservoir to the sump for lubricating the crown wheel. The pump is selectively operable to pump fluid from the sump to the reservoir.

Abstract: An electronic differential lock assembly includes a shift collar that is movable in response to an electronic signal from an unlocked position where axle shaft speed differentiation under predetermined conditions is permitted to a locked position where a pair of axle shafts is fixed for rotation together. Speed differentiation is provided by a differential that includes a differential gear assembly supported within a differential case. A coil surrounds the shift collar and is selectively energized to move the shift collar from the unlocked position to the locked position. The shift collar is splined to one of the axle shafts and is selectively splined to the differential case to lock the axle shafts together. The electronic differential lock assembly includes a return spring that automatically disengages the shift collar from the differential case once the coil is no longer energized.

Abstract: An axle assembly having two hubs, each for connection to a wheel, a housing for differential gears and a mounting arrangement for a braking system for braking a connected wheel. The housing has a depression formed therein. The depression is configured so as to accommodate: (a) when the mounting arrangement has a drum brake mounted thereon, movement of a slack adjuster of the drum brake in a direction away from one of the hubs nearest the drum brake so as to allow detachment of the slack adjuster; and/or (b) when the mounting arrangement has a disc brake mounted thereon, an air chamber of the braking system, wherein the air chamber is capable of being partially accommodated within the depression.

Abstract: A transmission system includes a housing having a sump. A crown wheel and pinion are positioned within the housing. The transmission system further includes a reservoir having an inlet system and an outlet system. Rotation of the crown wheel causes the oil to be transferred from the sump to the reservoir via the inlet system, and the outlet system allows oil to pass from the reservoir to the sump.

Abstract: A drive axle assembly that may include an input shaft, an intermediate shaft, an output shaft, and an actuator unit. The actuator unit may move the intermediate shaft between a first position in which the intermediate shaft transmits torque to the output shaft and a second position in which the intermediate shaft does not transmit torque to the output shaft.

Abstract: A drive axle assembly that may include an input shaft, an output shaft, a lock collar, and a pinion. The actuator unit may move the lock collar between a first position in which the torque is transmitted from the input shaft to the pinion and a second position in which torque is not transmitted to the pinion.

Abstract: An axle has a central crown wheel receiving portion with a pinion side and an opposite side. The opposite side is defined by a first crown wheel bowl for receiving a part of a crown wheel, the first crown wheel bowl having a peripheral edge. The axle includes a second crown wheel bowl for receiving the part of the crown wheel. The second crown wheel bowl is nested with the first crown wheel bowl and is attached to the first crown wheel bowl at a peripheral edge to define a reservoir.

Abstract: An electronic differential lock assembly includes a shift collar that is movable in response to an electronic signal from an unlocked position where axle shaft speed differentiation under predetermined conditions is permitted to a locked position where a pair of axle shafts are fixed for rotation together. Speed differentiation is provided by a differential that includes a differential gear assembly supported within a differential case. A coil surrounds the shift collar and is selectively energized to move the shift collar from the unlocked position to the locked position. The shift collar is splined to one of the axle shafts and is selectively splined to the differential case to lock the axle shafts together. The electronic differential lock assembly includes a return spring that automatically disengages the shift collar from the differential case once the coil is no longer energized.

Abstract: A differential gear casing of flower pot construction has an outer surface which is configured for receiving a crown wheel, whereby the crown wheel can be pressed onto the outer surface by different amounts for different applications. The outer surface is free from projections such that the crown wheel can be mounted on the outer surface from any axial direction. The outer surface defines a band on the differential gear casing and is parallel with a central axis of the differential gear casing. The crown wheel is secured to the differential gear casing using an axial weld line. In other embodiments, the crown wheel and/or a cover for the differential gear casing are secured in place using axial and/or radial weld lines.