Abstract: After a speed change operation mechanism has changed gear position during a shift in a vehicle, a controller operates an actuator to put a clutch into a partial clutch engagement state, thereby reducing difference rotation Nd of the clutch, and temporarily lowers an output of an engine below a normal-time output. After the difference rotation of the clutch is reduced, the controller returns the engine output to the normal-time output, and operates the actuator to bring the clutch into a full capacity state. The standard difference rotational speed Nds is variable according to the throttle position Th detected by the engine load detection means.

Abstract: In a speed change apparatus for a vehicle, a controller stores as a clutch-disengaging shift spindle angle ?1 a position at which a clutch is disengaged when a shift spindle is rotated in a first direction. The controller controls the shift spindle by a first step W1 of rotating the shift spindle in the first direction until a disengaging-side target angle Ta1 is reached; a second step W2 of returning the shift spindle in a second direction opposite to the first direction; and a third step W3 of rotating the shift spindle in the first direction up to the clutch-disengaging shift spindle angle ?1 and thereafter rotating the shift spindle in the second direction to return the shift spindle, upon detection of an output from a drum angle sensor, the output corresponding to shallow engagement of dog teeth.

Abstract: After a speed change operation mechanism has changed gear position during a shift in a vehicle, a controller operates an actuator to put a clutch into a partial clutch engagement state, thereby reducing difference rotation Nd of the clutch, and temporarily lowers an output of an engine below a normal-time output. After the difference rotation of the clutch is reduced, the controller returns the engine output to the normal-time output, and operates the actuator to bring the clutch into a full capacity state. The standard difference rotational speed Nds is variable according to the throttle position Th detected by the engine load detection means.

Abstract: A transmission system of a vehicle includes a starting clutch, a change clutch, a stepped transmission, a single spindle, a gear position sensor, an actuator, and a transmission controller. The change clutch and the stepped transmission are operated via the single spindle. The gear position sensor is to detect a shift stage of the stepped transmission. The actuator is to rotate the single spindle. The transmission controller, in a case where an engine is started in a state in which the shift stage of the stepped transmission is set in second gear or higher, is configured to control the actuator to carry out shift-down operation and configured to limit output of the engine so that an engine rotation speed becomes a value smaller than a predetermined value until the shift stage of the stepped transmission is set in neutral or first gear.