INSULATION 3C8443 - Caterpillar

transmission ECM controls the torque converter lockup. When the ECM activates the lockup solenoid the lockup clutch in the torque converter mechanically connects the torque converter input shaft to the torque converter output shaft. This efficiently connects the power train to the engine. The ECM keeps the lockup clutch engaged as much as possible during normal operation. When the transmission shifts the lockup solenoid is deactivated for smoother shifting. The machine is in torque converter drive when the lockup solenoid is deactivated. The NEUTRAL is in torque converter drive. First gear is torque converter drive on the low end and direct drive on the high end. The transmission gears (two through eight) are direct drive.