A method for shifting between a low speed range and a high speed range for a two-speed transfer case in a four-wheel drive vehicle includes determining a target transmission gear ratio and a desired transfer case range based on the current vehicle speed and the initial transfer case range. The transmission is shifted to the target transmission gear ratio when it is determined that the vehicle speed is in an appropriate range. The transfer case input torque is reduced to a minimum value, and the transfer case is shifted to neutral. The method further includes adjusting the engine speed and transmission gear setting to control the transmission output shaft speed to a desired range. The transfer case is shifted from neutral to the desired transfer case range when the transmission output shaft speed is within the desired range of transmission output shaft speed.

A vehicle transfer case is provided including input and output shafts mounted within a housing, a secondary shaft selectively driven by the output shaft, a first hub having an inner diameter splined section having a first extreme neutral position with exclusive torsional engagement with the output shaft, and in a second intermediate high position having torsional engagement with the output shaft and input shafts, and in a third extreme low position having exclusive torsional engagement with the input shaft. A second hub is provided, rotatably mounted on the first hub and axially fixed therewith. The second hub is torsionally fixed to the output shaft, and a shift fork is provided to translate the second hub. A planetary gear set is provided, having a ring gear, a plurality of planet gears connected to each other by a carrier and a sun gear; and wherein in the extreme neutral position the output shaft is disengaged from the input shaft, and in the second intermediate position the input shaft is directly connected to the output shaft without rotating the planetary gear set, and in the extreme third position the first hub torsionally connects the input shaft to the sun gear, and the second hub is connected with the carrier.

A vehicle transfer includes an input shaft, an output shaft, an output member, a clutch, a motor, a screw mechanism, a transmitting mechanism, a fork shaft, an amplifying link mechanism, a high-low switching mechanism, and a fork. The fork shaft is configured to move in an axial direction of the fork shaft. The amplifying link mechanism is connected to the nut member and the fork shaft. The amplifying link mechanism is configured to amplify an amount of movement of the nut member in the direction of the common axis and transmit the amplified amount of movement to the fork shaft. The fork is connected to the fork shaft. The fork is configured to transmit moving force of the fork shaft to the high-low switching mechanism such that the high-low switching mechanism switches between the high-speed gear and the low-speed gear.

A transfer includes an input shaft, an output shaft, an output member, a high-low switching mechanism, a clutch, an actuator, a screw mechanism, a first transmitting mechanism, a cam engaging member, a drum cam, and a second transmitting mechanism. The high-low switching mechanism is configured to change a rate of rotation of the input shaft and transmit a resultant rotation to the output shaft. The second transmitting mechanism is configured to transmit a movement of one of the drum cam and the cam engaging member that is connected to a second shaft to the high-low switching mechanism via the second shaft such that the high-low switching mechanism switches between the high-speed gear and the low-speed gear.

A shaft seal for an axle assembly can include a support body with a circumferentially-extending outer wall member and a radial wall member coupled to the outer wall member and extending radially inwardly therefrom. Sealant disposed on an outside circumferential surface of the outer wall member can form a seal with a surface of a housing bore. A lip can be coupled to the radial wall member and extend radially inward thereof. The lip can form a seal between the radial wall member and an outer surface of a shaft. An annular flange can be coupled to the outer wall member and extend radially outward of an intersection of the outer wall member and the radial wall member, while having a maximum diameter that is smaller than a maximum diameter of the outer wall member. The flange and outer wall member can cooperate to define an annular channel.

A drive switching apparatus includes an output member connected to a drive switching member and displacing the drive switching member to three shift positions by being rotated, a deceleration mechanism decelerating rotation of an input portion connected to an electric motor and outputting the rotation to an output portion, a rotation absorption mechanism including an elastic member interposed between an input element connected to the output portion and an output element connected to the output member, the rotation absorption mechanism absorbing rotation of the input element in a case where rotation of the output element is restricted during the rotation of the input element, aid a switch operation portion provided at the output element, the switch operation portion turning a switch on and off according to a rotational position of the output member in order to detect the shift positions of the drive switching member.

An active transfer case having an integrated torque transfer component combining a multi-plate mode clutch with a sprocket of a chain and sprocket transfer assembly to provide a stacked arrangement therebetween.

Removable devices and systems for operating the four wheel drive (4WD) system of a tow vehicle having an electronically controllable part time 4WD system including a selectable 4WD low range mode are described. The removable device may comprise a first interface for coupling the removable device to a selector, the selector providing an indication of a desired operating mode for the 4WD system; a second interface for coupling the removable device to a controller-area network bus of the tow vehicle; a memory storing vehicle control codes; and at least one controller communicatively coupled to both the first interface and the second interface. The removable device, and system, may allow a vehicle operator to operate the tow vehicle in two-wheel drive low range mode.

A clutch control device is provided for a four-wheel drive vehicle. The clutch control device is able to suppress the elevation of the temperature of the oil supplied to a friction clutch during two-wheel drive travel when the friction clutch is released. The clutch control device includes a dog clutch and an electronic control coupling. The friction clutch is housed in a coupling case. When the dog clutch and the friction clutch are released, a two-wheel drive mode is selected. The coupling case has a passage opening that is closed to retain lubrication oil in an oil chamber with respect to a clutch chamber that houses the friction clutch. When oil stirring conditions are met thereafter, the passage opening is opened and the lubrication oil is allowed to flow into the clutch chamber from the oil chamber.

A sequential shift transmission is provided that includes a transmission portion, a range box portion, a transfer portion and at least one shift actuator. The transmission portion has sequential gearing. The range box portion is operationally coupled to the transmission portion and has range gearing that includes a low range gear and a high range gear. The transfer portion is operationally coupled to the range box portion to output torque from the sequential shift transmission. The at least one shift actuator is configured and arranged to selectively change the sequential gearing and the range gearing.