• When shifting ND or NR, the pressure control solenoid is driven to control the clutch engagement pressure optimally.
• The clutch engagement pressure is directly controlled to be optimal by the duty-cycle solenoid valves.
• When shifting 2GR3GR, 3GR4GR, 3GR2GR, or 4GR3GR, the clutch pressures of engagement side and release side are controlled simultaneously. As a result, the clutch capacities of both clutches are controlled relatively when switching the clutches. This prevents sudden increases in engine speed and clutch interlocks during shifting, realizing smooth and responsive shifting.