Abstract: Provided herein is a method of disconnecting and connecting elements of a tandem axle system (100) drivingly connected to an engine (206) and transmission (204) of a vehicle, the method including the steps of: providing a tandem axle system (100) having: an inter-axle differential and clutch assembly (102) in driving engagement with the engine, wherein the inter-axle differential and clutch assembly includes an inter-axle differential (108) and an inter-axle differential lock (110); a forward axle assembly (104) including a differential assembly (116), a disconnect assembly (114) and two axle half shafts (104a, 104b); and a rear axle assembly (106) including a differential assembly (120), a disconnect assembly (122) and two axle half shafts (106a, 106b); providing a control system (300) in communication with the inter-axle differential lock, the disconnect assemblies and the engine; detecting (402) a disconnect opportunity; commanding (404) the engine torque set to zero; disconnecting (406) the axle half shaf

Abstract: Provided herein is an electric axle including a differential assembly drivingly connected to a first axle half shaft and a second axle half shaft, wherein the first and second axle half shafts each have a wheel coupled to the ends thereof; an electric motor/generator drivingly connected to a first rotatable shaft; a first gear set having a first gear connected to the first rotatable shaft and a second gear connected to a second rotatable shaft; a second gear set having a first gear connected to the second rotatable shaft and a second gear selectively connected to a third rotatable shaft; a third gear set having a first gear connected to the third rotatable shaft and a second gear drivingly connected to the differential assembly; and a selector device configured to selectively connect the third rotatable shaft to the second gear of the second gear set or the first rotatable shaft.

Abstract: Provided herein in a method of disconnecting and connecting a tandem axle system, the method including the steps of: providing a tandem axle system including a primary clutch in driving engagement with a prime mover, an inter-axle differential and clutch assembly including an inter-axle differential and an inter-axle differential lock in selective driving engagement with the primary clutch, a forward axle assembly having a disconnect assembly, a rear axle assembly having a disconnect assembly, and a control system in communication with the inter-axle differential lock, the differential lock assembly, and the disconnect assemblies; disconnecting the disconnect assemblies of the forward and rear axle assemblies; engaging the inter-axle differential lock; disengaging the primary clutch; matching rotational speeds of the axle half shafts disconnect assemblies of the front and rear axle assemblies; connecting the disconnect assemblies of the forward and rear axle assemblies; and engaging the primary clutch.

Abstract: A tandem axle assembly capable of accommodating variations in driveline length is provided. The tandem axle assembly includes forward and rear axle assemblies each having a wheel differential with the forward axle assembly further including an inter-axle differential for dividing power between the two wheel differentials. A male-female slip connection is formed between two members at one or more of the following intersections: the connection between a power input shaft driving the inter-axle differential and a power transmission shaft for transferring power from a vehicle driveshaft to the power input shaft; the connection between an output shaft driven by the inter-axle differential and an output yoke of an intermediate drive shaft assembly extending between the forward and rear axle assemblies; and the connection between an input yoke of the intermediate drive shaft assembly and a pinion shaft in the rear axle assembly drivingly coupled to the rear wheel differential.

Abstract: A tandem axle assembly capable of accommodating variations in driveline length is provided. The tandem axle assembly includes forward and rear axle assemblies each having a wheel differential with the forward axle assembly further including an inter-axle differential for dividing power between the two wheel differentials. A male-female slip connection is formed between two members at one or more of the following intersections: the connection between a power input shaft driving the inter-axle differential and a power transmission shaft for transferring power from a vehicle driveshaft to the power input shaft; the connection between an output shaft driven by the inter-axle differential and an output yoke of an intermediate drive shaft assembly extending between the forward and rear axle assemblies; and the connection between an input yoke of the intermediate drive shaft assembly and a pinion shaft in the rear axle assembly drivingly coupled to the rear wheel differential.

Abstract: A clutch actuator includes an outer cylinder housing having a plurality of ramps formed on an inner cylindrical surface thereof. Each of the ramps has a radially inwardly facing surface which includes a forwardly facing tapered surface and a rearwardly facing tapered surface. A hollow cylindrical piston is disposed concentrically within the outer cylinder housing and has a plurality of axially extending protrusions formed thereon. Preferably, the number of such protrusions is equal to the number of the ramps formed on the outer cylinder housing, and the protrusions are circumferentially interleaved within the ramps formed on the outer cylinder housing. Each of the protrusions has a radially outwardly facing surface which includes a forwardly facing tapered surface and a circumferentially extending groove. An inner cylinder housing is disposed concentrically within the piston.

Abstract: An interlock assembly for a vehicle transmission prevents more than one of a plurality of shift rails from being simultaneously moved axially out of a central neutral position to a gear engaging position. The interlock assembly includes an interlock plate having four semi-circular cut-outs (one for each of the shift rails) and two relative large interior openings. The interlock assembly further includes a backing plate which is somewhat smaller than the interlock plate and has two relatively small interior openings. A pair of threaded fasteners extend through the small openings of the backing plate and through respective spacer bushings disposed in the large interior openings of the interlock plate into threaded engagement with the housing of the hydraulic actuator. The spacer bushings prevent the interlock plate from being frictionally engaged between the backing plate and the housing of the hydraulic actuator.

Abstract: A transmission includes a plurality of shift rails, each of which is axially movable forwardly and rearwardly from a center neutral position to respective gear engaging positions. The lower shift rails are provided for manual shifting among the lower gear ratios of the transmission. The highest shift rail is provided for selective manual or automatic shifting among the highest two gear ratios of the transmission. An idler rail is disposed adjacent to the highest shift rail. For manual shifting, the idler rail is connected to the highest shift rail, and a manually operable shift lever is used to move both the idler rail and the highest shift rail. For automatic shifting, the idler rail is disconnected from the highest shift rail, and an automatic shift member is moved into cooperation with the highest shift rail. Rotation of the automatic shift shaft causes corresponding movement of the automatic shift member.

Abstract: A transmission includes a plurality of shift rails, each of which is axially movable forwardly and rearwardly from a center neutral position to respective gear engaging positions. The lower shift rails are provided for manual shifting among the lower gear ratios of the transmission. The highest shift rail is provided for selective manual or automatic shifting among the highest two gear ratios of the transmission. An electronic controller is provided for controlling the automatic shifting of the transmission in response to sensed operating conditions of the vehicle. A circuit is provided for sensing the rotational position of the automatic shift shaft and for generating an electrical signal which is representative of the actual position thereof, which is also representative of the actual position of the highest shift rail, to the electronic controller. The transmission also includes a shift lever having an end which extends through an opening formed in a case.

Abstract: A transmission includes a plurality of shift rails, each of which is axially movable forwardly and rearwardly from a center neutral position to respective gear engaging positions. The lower shift rails are provided for manual shifting among the lower gear ratios of the transmission. The highest shift rail is provided for selective manual or automatic shifting among the highest two gear ratios of the transmission. An idler rail is disposed adjacent to the highest shift rail. For manual shifting, the idler rail is connected to the highest shift rail, and a manually operable shift lever is used to move both the idler rail and the highest shift rail. For automatic shifting, the idler rail is disconnected from the highest shift rail, and an automatic shift member is moved into cooperation with the highest shift rail. Rotation of the automatic shift shaft causes corresponding movement of the automatic shift member.

Abstract: A lockout device is provided for inhibiting the selection of certain gear combinations in range shift type transmission. The lockout device comprises an air cylinder mounted to the transmission housing. The air cylinder includes a rod selectively translatable between a retracted position and an extended position. The rod is normally urged to its retracted position, and extends through an aperture in the housing in its extended position to engage a notch in a selected shift rail. The air cylinder and the high range air line are operably interconnected, whereby a shift to high range simultaneously activates the air cylinder, extending the rod into the recess in the shift rail to thereby selectively limit axial translation of the shift rail. The lockout device is easily removable.

Abstract: Power take-off control apparatus which automatically shifts a vehicle speed range transmission into neutral whenever a power take-off mechanism is engaged to prevent accidental engagement of a drive gear while the power take-off mechanism is in use. A piston is moved in response to fluid pressure to shift the speed range transmission between high and low speed gear ranges. The power take-off mechanism is engaged in response to fluid pressure from a control valve. Whenever fluid pressure is applied to engage the power take-off mechanism, the fluid pressure moves the piston to an intermediate neutral position to disengage the vehicle drive.

Abstract: A shifter assembly for a manual transmission includes a yoke mounted within a shift tower for pivotable movement about a shifting axis. A shift lever is mounted within the yoke for pivotable movement about a selecting axis located above and perpendicular to the shifting axis. The lower end of the shift lever extends into cooperation with conventional shift rails disposed within the transmission. By locating the shifting axis relatively close to the shift rails, a mechanical advantage is provided when moving the shift lever about the shifting axis. Since the selecting axis is located farther away from the shift rails than the shifting axis, the lower end of the shift lever travels farther when the upper end of the shift lever is moved a predetermined distance about the selecting axis than when the upper end of the shift lever is moved about the shifting axis.

Abstract: A hill holder device for a vehicle manual transmission includes a releasable one-way clutch which is coupled to the countershaft of the transmission. In particular, the one-way clutch includes a sprag clutch having an inner race secured to the countershaft, and an outer race secured to the vehicle transmission case by means of a releasable locking mechanism. When the locking mechanism is in its locked position, the sprag clutch enables rotation of the countershaft in only one direction. Thus, if the transmission is in a forward gear and comes to a stop on an ascending grade, the hill holder will lock the vehicle drive train and prevent the vehicle from rolling back down the grade, without requiring the driver to apply the brakes. Similarly, if the vehicle is in a reverse gear and is stopped on a descending grade, the hill holder will prevent the vehicle from rolling in a forward direction down the grade.

Abstract: A method of testing a manual transmission utilizes a test fixture adapted to be positioned on the transmission shift tower mounting pad. The test fixture includes a plurality of cylinders equal in number to the number of transmission shift rails, with each cylinder being connected to a separate actuating arm operatively engaging a separate one of the shift rails. The transmission is positioned in a test stand for supplying power to the transmission input while simultaneously loading the output, and providing an oil flush. The cylinders are then actuated in a predetermined sequence to independently actuate the shift rails and shift the transmission in a predetermined sequence. In accordance with the present invention, a constant force is applied to the shift rail to effect a shift, and the time required to complete a particular shift is measured. This measured time is then compared to a predetermined reference time, which represents the time period the shift should have taken in a satisfactory transmission.