PLATE-ROPS 6V3417 - Caterpillar

Fourth (Direct Drive)
When the transmission control is moved to the FOURTH position, the rotor for the shift lever switch is moved to the FOURTH position. With the shift lever switch in this position, current flows from the Power Train ECM through the shift lever switch to machine ground.The Power Train ECM determines that FOURTH gear is needed. The rotary selector spool turns the rotor on the transmission gear switch as the transmission shifts through the gears. As the rotary selector spool turns, the rotor on the transmission gear switch is turned by a flexible coupling. When the rotor on the transmission gear switch is in the FOURTH position, current flows from the Power Train ECM through the transmission gear switch to machine ground. The Power Train ECM determines that the shift is complete. The machine is now in FOURTH gear and the machine is in direct drive.Shifting Procedures
The following sections will explain the operations of automatic upshifts and downshifts. Except for different electrical wires that must be grounded or activated, the shifting sequence is basically identical for all speeds.Typical Automatic Upshift (SECOND to THIRD)
When the transmission control is put in THIRD speed position, the rotor for the shift lever switch is turned to the THIRD speed position. Current goes from the Power Train ECM through the shift lever switch to machine ground. This current flow and a signal from the transmission speed sensor will inform the Power Train ECM that an upshift is needed. The upshift to THIRD speed position from SECOND speed position is automatic when the correct ground speed signal from the transmission speed sensor is sent to the Power Train ECM, and the transmission control is in THIRD speed position or above THIRD speed position.The Power Train ECM stops current flow to the lockup clutch solenoid when a shift is necessary. The lockup clutch solenoid deactivates. Hydraulic oil to the lockup clutch stops and the machine is in torque converter drive for a moment. At the