A mechanical creeper mode selection system for a transmission of a work vehicle is provided, in which the transmission includes one or more range modes having one or more range mode shift mechanisms each driven by an electrohydraulic circuit. The system includes a creeper mode selection lever movable by an operator to select a creeper gear range. The system also includes a sensor that observes a position of the creeper mode selection lever and generates sensor signals based thereon. The system includes a controller that processes the sensor data to determine a movement of the creeper mode selection lever and outputs one or more control signals to the electrohydraulic circuit to position the one or more range mode shift mechanisms in a range neutral mode based on the movement of the creeper mode selection lever.

A vehicle park lock control method is presented with range positions including a P-range position and an N-range position in each of which a driving force is prevented from being transmitted to a driving wheel of a vehicle. A park lock mechanism is activated when in the P-range position. An operator is allowed to select whether or not to cause the park lock mechanism to be activated in response to key-off operation when in the N-range position. In response to continuous shifting of a range selector to one or more specific ones of the range positions, the park lock mechanism is prevented from being activated in response to key-off operation when in the N-range position.

An automatic park lock for an off road or recreational utility vehicle includes a shift interlock solenoid with a spring biased plunger engaging and locking an operator shift lever in the park position. A cam surface on the operator shift lever slopes between a first end and a second end, and has a groove to lock the plunger to the park position. A controller energizes the shift interlock solenoid to retract the plunger when a plurality of operating parameters are satisfied.

An apparatus for controlling a vehicle includes a vehicle state detector for detecting a vehicle state, a function unit that performs at least one vehicle function, an operation unit that enables a transmission operation to allow selection of a transmission stage from among a plurality of transmission stages, and a position adjusting unit to switch the operation unit between a first position where the transmission operation is disabled and a second position where the transmission operation is enabled, by rotating the operation unit with respect to the functional unit, based on the detected vehicle state.

A method for turning off an internal combustion engine (ICE) where a clutch arrangement has first and second clutches that respectively couple the ICE to first and second input shafts of a transmission. The input shafts are drivingly connected to first and second sets of gears, respectively. The sets of gears are connected to an output shaft of the transmission. The method includes: controlling the ICE in an idling state when the vehicle is in standstill, wherein the clutches are in open positions; engaging the first input shaft with a first pre-selected gear, and engaging the second input shaft with a second pre-selected gear; initiating an engine turning off command; stopping the ICE by at least partly closing the clutches for simultaneously introducing torque transfer to the clutches into a transmission tie-up state for a controlled engine stop, wherein engine inertia of the ICE is captured in the clutches.

A clutch includes a clutch disk that rotates by receiving motive power from an engine and a clutch plate switched between an engaged state in which it is engaged with the clutch disk and a disengaged state in which it is not engaged with the clutch disk. A controller calculates a coefficient of friction μ between the clutch disk and the clutch plate based on a time period Δt elapsed from a first time point when the number of relative rotations of the clutch disk and the clutch plate attains to a first number of rotations to a second time point when a second number of rotations smaller than the first number of rotations is attained, in a state in which the clutch disk rotates while transfer of motive power from the engine to the clutch disk is cut off and in the engaged state.

In an apparatus for controlling an automatic transmission having gear engaging mechanisms installed to engage one of gears to establish n-th speed when supplied with hydraulic pressure discharged from an oil pump driven by a prime mover, an electromagnetic pressure-regulating valve installed to pressure-regulate the hydraulic pressure, an electromagnetic shift valve installed at a hydraulic passage to supply the hydraulic pressure to the gear engaging mechanisms, and a current supply circuit to supply current to the solenoid valve, cut-off of current supply to the solenoid valve from the current supply circuit is delayed by a predetermined time period, when the ignition switch is turned off.

A method of controlling an automatic transmission mounted on a vehicle having an automatic engine stop mechanism for automatically stopping and restarting an engine, is provided. The transmission includes a piston having first and second surfaces, friction plates, engaging and disengaging hydraulic pressure chambers, a hydraulic pressure control valve for supplying/discharging hydraulic pressure to/from the chambers, first and second oil paths communicating the control valve with the chambers, a pressure reducing valve for preventing pressure of the disengaging chamber from exceeding a given set pressure, a hydraulic pressure supply device for supplying pressure to the control valve in the automatic stop state, and a mechanical oil pump for supplying pressure to the control valve while the engine is driving, the second surface having a larger pressure receiving area than the first surface. The method includes adjusting the set pressure to be lower in the automatic stop state than while driving.

A hydraulic control apparatus includes: a branch path that branches from a passage connected to an oil pump and equipment to which oil is supplied by the oil pump; an accumulator connected to the branch path to accumulate and discharge high-pressure oil supplied from the branch path; a check valve provided in an oil inlet path through which oil flows into the accumulator; a balance valve unit including a reference pressure chamber, a balance valve body that is biased toward an opening side by an opening compression spring, and a control pressure chamber; and a control solenoid that introduces or discharges the high-pressure oil into or from the control pressure chamber.

A recreational vehicle is provided including a power source, such as an engine or an electric motor, and a transmission having a variable gear ratio. A sub-transmission coupled to an output of the transmission includes a plurality of selectable gear configurations including park gear and at least one of a forward gear, a neutral gear and a reverse gear. An electronic controller is operative to electronically control the gear configuration of the sub-transmission in response to a set of conditions.