Abstract: 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.

Abstract: A vehicle drive system capable of selectively providing all-wheel drive and single-driven-axle modes includes a front drive unit having a planetary gearset with a grounded ring gear and a sun gear driven by the transaxle's drive spool via an input shaft, and a differential selectively coupled by a dog clutch to one of the sun gear or the planetary carrier, or neither of them, to thereby selectively provide both an available low range and a front axle disconnect. The front drive unit further defines a power take-off unit with a clutch selectively coupling the input shaft to a propshaft. The rear drive unit includes a planetary gearset with a grounded ring gear, a sun gear driven by the propshaft, and a differential selectively coupled by a dog clutch to one of the sun gear or the planetary carrier, or neither of them, to thereby likewise selectively provide both an available low range and a rear axle disconnect.

Abstract: A vehicle drive system capable of selectively providing all-wheel drive and single-driven-axle modes includes a front drive unit having a planetary gearset with a grounded ring gear and a sun gear driven by the transaxle's drive spool via an input shaft, and a differential selectively coupled by a dog clutch to one of the sun gear or the planetary carrier, or neither of them, to thereby selectively provide both an available low range and a front axle disconnect. The front drive unit further defines a power take-off unit with a clutch selectively coupling the input shaft to a propshaft. The rear drive unit includes a planetary gearset with a grounded ring gear, a sun gear driven by the propshaft, and a differential selectively coupled by a dog clutch to one of the sun gear or the planetary carrier, or neither of them, to thereby likewise selectively provide both an available low range and a rear axle disconnect.

Abstract: A vehicle drive system capable of selectively providing all-wheel drive and single-driven-axle modes includes a front drive unit having a planetary gearset with a grounded ring gear and a sun gear driven by the transaxle's drive spool via an input shaft, and a differential selectively coupled by a dog clutch to one of the sun gear or the planetary carrier, or neither of them, to thereby selectively provide both an available low range and a front axle disconnect. The front drive unit further defines a power take-off unit with a clutch selectively coupling the input shaft to a propshaft. The rear drive unit includes a planetary gearset with a grounded ring gear, a sun gear driven by the propshaft, and a differential selectively coupled by a dog clutch to one of the sun gear or the planetary carrier, or neither of them, to thereby likewise selectively provide both an available low range and a rear axle disconnect.

Abstract: A method of operating a multi-mode drive system that precisely orchestrates a shift between gear ratios in a power take off unit and a rear drive module. The method first shifts between gear ratios in the power take off unit and then, depending upon the success or failure of the shift of the power take off unit, shifts between gear ratios in the rear drive module.

Abstract: A method of operating a multi-mode drive system that precisely orchestrates a shift between gear ratios in a power take off unit and a rear drive module. The method first shifts between gear ratios in the power take off unit and then, depending upon the success or failure of the shift of the power take off unit, shifts between gear ratios in the rear drive module.

Abstract: The present invention provides a system for providing an improved compact power transfer unit for use in motor vehicles having a front wheel drive transverse based engine and transaxle, and, more particularly, to a power transfer unit for use with a transaxle arrangement capable of providing all-wheel drive or four-wheel drive. The present invention discloses a planetary gear utilizing a fixed ring gear, the planetary gear capable of selectively engaging a low range output from the power transfer unit for propelling the vehicle when driven in off-road conditions requiring higher torque and slower speeds. The vehicle driver can selectively engage a normal, high range where torque flows through the planetary gear directly to the drive shaft with no gear reductions, or the driver may selectively engage the low range where the torque flowing into the planetary gear is redirected and reduced thereby providing higher torque with reduced speed.

Abstract: A vehicle drive system capable of selectively providing all-wheel drive and single-driven-axle modes includes a front drive unit having a planetary gearset with a grounded ring gear and a sun gear driven by the transaxle's drive spool via an input shaft, and a differential selectively coupled by a dog clutch to one of the sun gear or the planetary carrier, or neither of them, to thereby selectively provide both an available low range and a front axle disconnect. The front drive unit further defines a power take-off unit with a clutch selectively coupling the input shaft to a propshaft. The rear drive unit includes a planetary gearset with a grounded ring gear, a sun gear driven by the propshaft, and a differential selectively coupled by a dog clutch to one of the sun gear or the planetary carrier, or neither of them, to thereby likewise selectively provide both an available low range and a rear axle disconnect.

Abstract: Methods and systems are described to automatically lock and unlock a front axle disconnect mechanism in an all-wheel drive (AWD) system responsive to driving conditions to reduce parasitic losses and increase fuel efficiency. A control algorithm is described which automatically determines whether the front axle disconnect mechanism should lock or unlock responsive to various sensor readings throughout the vehicle. The sensor readings relate to the driving conditions. Advantageously, the present disclosure automatically decides the best mode for optimum fuel economy while safely responding to driving conditions, and therefore removes the requirement for a driver to select the operating mode.

Abstract: Methods and systems are described to automatically lock and unlock a front axle disconnect mechanism in an all-wheel drive (AWD) system responsive to driving conditions to reduce parasitic losses and increase fuel efficiency. A control algorithm is described which automatically determines whether the front axle disconnect mechanism should lock or unlock responsive to various sensor readings throughout the vehicle. The sensor readings relate to the driving conditions. Advantageously, the present disclosure automatically decides the best mode for optimum fuel economy while safely responding to driving conditions, and therefore removes the requirement for a driver to select the operating mode.

Abstract: The present invention provides a system for providing an improved compact power transfer unit for use in motor vehicles having a front wheel drive transverse based engine and transaxle, and, more particularly, to a power transfer unit for use with a transaxle arrangement capable of providing all-wheel drive or four-wheel drive. The present invention discloses a planetary gear utilizing a fixed ring gear, the planetary gear capable of selectively engaging a low range output from the power transfer unit for propelling the vehicle when driven in off-road conditions requiring higher torque and slower speeds. The vehicle driver can selectively engage a normal, high range where torque flows through the planetary gear directly to the drive shaft with no gear reductions, or the driver may selectively engage the low range where the torque flowing into the planetary gear is redirected and reduced thereby providing higher torque with reduced speed.