Gearbox Solenoid Valve Function When operate the transmission manipulator handle to conduct forward and reverse each shift, the electric signal is sent to the four solenoid valves mounted on the gearbox control valve to control the slid valve of each shift according to the open and close solenoid combination. Operation 1. Solenoid Valve Switch Off The oil from oil pump is blocked by the solenoid valve, which make the shift slid valve is moved to left side under the action of spring force, consequently the oil at the port E flows into the K3 clutch. 2.
Solenoid Valve Switch On When operate the transmission manipulator handle, the solenoid valve will block the drain port and switch on the oil from oil pump to port A and B of shift slid valve, the slid valve is moved to right side due to the action of oil pressure overcomes the spring force, consequently the oil from oil pump is flowed to the K1 clutch. Operation Chart of Solenoid Valve and Clutch :
Current Action From Oil pump K3 clutch From Oil pump K1 clutch 20-42 Shifts Solenoid Valve M1 M2 M3 M4 Forward 1st Shift ● ● ● Forward 2nd Shift ● ● ● Forward 3rd Shift ● ● Forward 4th Shift ● ● Forward 5th Shift ● Forward 6th Shift ● Neutral Reverse 1st Shift ● ● ● ● Reverse 2nd Shift ● ● ● Reverse 3rd Shift ● ●