REGULATOR 8D4773 - Caterpillar

Illustration 1 g02705696
Power from the diesel engine is sent from the flywheel to torque converter. The torque converter is splined to the engine flywheel. The torque converter is fastened to transmission by bolts. Power flows directly from the torque converter to the transmission input shaft. The torque converter output gear is meshed to the transmission input gear.The transmission output shaft is connected to the input gear in output transfer gear case by splines. Power is sent through the input gear to the output gear. The output gear sends power through rear drive shaft to the rear differential. The output gear also sends power to the front differential through front drive shaft. The bevel gear and pinion of each differential sends the power to the final drives through the differentials and through the sun gear shafts. Axle shafts transfer the power from final drives and to the wheels.
Illustration 2 g02705736
Six hydraulically activated clutches in transmission provide four forward speeds and four reverse speeds. Speed selections and direction selections are made manually with transmission direction and speed control. The autoshift control will make speed selections if the machine is in automatic mode. The variable shift control uses the on/off option integrated into the GenIII display to provide auto shift points.The power train electronic control system electronically controls transmission shifts. The power train electronic control system shifts the transmission. In order for the transmission to be shifted to the desired speed and the desired direction, power train ECM receives the operator input from transmission direction and speed control and the left brake pedal position sensor. The power train ECM signals the modulating valve (transmission clutch) of the speed clutch that is selected. The power train ECM signals the modulating valve (transmission clutch) of the direction clutch that is selected. The output signal energizes the solenoids of modulating valves (transmission clutch) that are selected. The energized modulating valves (transmission clutch) electronically modulate the oil pressure of the clutches that are selected. The power train ECM can request automatic shifts. The power train ECM uses the following input signals to ensure steady engagement of the clutches: engine speed sensor, torque converter output speed sensor, transmission speed sensors and transmission oil temperature sensor .The transmission ECM also controls the following functions: neutral start, auto shift control, variable shift control, speed limiter and transmission neutralizer.