Driveline engagement/disengagement

摘要

In a transmission system having range shift levers (92, 96) mechanically linked to couplers (15, 25, 55, 65) and shiftable between first and second positions to select ranges of gears and electro-hydraulic powershift clutches (C1-C4) for selecting a gear within the range selected by the range shift lever (92, 96), the powershift clutches (C1-C4) are located on each side of at least one of the couplers, between the input shaft (10) and the coupler and between the output shaft (11) and the coupler. A dump solenoid (S3) is controlled by operation of a clutch pedal (78) to release fluid from the powershift clutches (C1-C4) as the clutch pedal (78) is depressed but before it reaches the fully depressed position so that the coupler is not being driven when coupler shifting takes place.