Solenoid Valves (Transmission Clutch)
 | |
| Illustration 1 | g00288431 |
Identification of Solenoid Valves (1) Solenoid valve for clutch 3. (2) Solenoid valve for clutch 4. (3) Solenoid valve for clutch 5. (4) Solenoid valve for clutch 1. (5) Solenoid valve for clutch 2. (6) Solenoid valve for clutch 6. | |
 | |
| Illustration 2 | g00288432 |
Solenoid Valve (Transmission Clutch) | |
The clutch solenoid valves are outputs of the transmission electronic control module (ECM). The purpose of the solenoid valve is to direct pilot oil to the ends of the control spool. The control spool will shift. This allows pressure oil to flow to the corresponding clutches. The power train ECM activates the appropriate solenoid valve for the required clutches for the speed and for the direction that has been selected.
Clutches 1 and 2 are for direction. Clutches 3, 4, 5 and 6 are for speed.
In order for the machine to move, one speed clutch solenoid and one direction clutch solenoid must be activated. When the transmission is in neutral, only clutch solenoid valve 3 is activated. When the transmission is neutralized, the solenoid for the direction clutch is deactivated. Only the speed clutch solenoid is activated. The clutch solenoid valve is energized by a PWM signal that is sent by the power train ECM.
The clutch solenoid valves have a connector with two contacts. One contact receives power from the corresponding connector contact of the power train ECM (J1-11, J1-17, J2-1, J2-2, J2-7 and J2-8). The other contact of all the solenoid valves join together. These wires return power to connector contact J1-7 and J2-3 of the power train ECM.
Note: The solenoid coils are not designed for 24 volt operation. The power train ECM sends a 24 volt PWM signal at a duty cycle which provides an average voltage of about 12 volts to the solenoid coils. Do NOT activate the coils with 24 DCV. The life of the coils will be drastically reduced.
Note: Engagement of the clutch is delayed for two seconds when the operator selects neutral. During this delay, the transmission is in a "no clutch neutral" state. None of the solenoid valves are energized during the "no clutch neutral" state. This "no clutch neutral" state is provided in order to improve the quality of directional shifts. The power train ECM momentarily prevents the engagement of the neutral clutch, as the operator shifts from forward direction to reverse direction or shifts from reverse direction to forward direction.
Ride Control Solenoid Valves
 | |
| Illustration 3 | g00774064 |
Ride Control Solenoid Valve | |
Earlier Ride Control Solenoid Valve
The earlier ride control system uses only one solenoid valve. The solenoid valve activates and the solenoid valve deactivates the ride control system. The earlier ride control solenoid is an output of the transmission electronic control module (ECM). The ride control solenoid has a connector with two contacts. One contact receives power from the connector contact J1-18 of the power train ECM. The other contact returns power to the connector contact J2-3 of the power train ECM.
Later Ride Control Solenoid Valves
The later ride control system uses two solenoid valves. The two solenoid valves activate and the two solenoid valves deactivate the ride control system. The ride control solenoids are outputs of the power train ECM. Each ride control solenoid has a connector with two contacts.
One of the solenoid valves is attached to the diverter valve. This solenoid valve has one contact that receives power from the connector contact J1-18 of the power train ECM. The other contact returns power to the connector contact J2-3 of the power train ECM.
The other solenoid valve has a contact that receives power from the connector contact J1-12 of the power train ECM. The other contact returns power to the connector contact J2-3 of the power train ECM.