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| Illustration 1 | g00293356 |
Location of Power Train Components (1) Diesel engine. (2) Torque converter. (3) Transmission. (4) Output transfer gears. (5) Rear final drives. (6) Rear drive shaft. (7) Front drive shaft. (8) Front final drives. | |
Power from diesel engine (1) is sent from the flywheel to torque converter (2). The torque converter is splined to the engine flywheel. The torque converter is fastened to transmission (3) 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 (4) by splines. Power is sent through the input gear to the output gear. The output gear sends power through rear drive shaft (6) to the rear differential. The output gear also sends power to the front differential through front drive shaft (7). 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 (5) and (8) to the wheels. An integral parking brake is mounted on the front of the output transfer gears.
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| Illustration 2 | g00571084 |
Block Diagram of the Power Train Electronic Control System (9) Transmission neutralizer limit switch (10) Transmission direction and speed control (11) ECAP service connector (12) CAT Data Link (13) Caterpillar Monitoring System (14) Caterpillar Monitoring System service connector (15) Power train electronic control module (ECM) (16) Autoshift switch (17) Transmission neutralizer override switch (18) Engine (19) Engine speed sensor (20) Torque Converter (21) Torque Converter output speed sensor (22) Modulating valves (transmission clutches) (23) Transmission oil temperature sensor (24) Transmission output speed sensors (two) (25) Differential (26) Transmission (27) Transmission intermediate speed sensors (if equipped) | |
Six hydraulically activated clutches in transmission (26) provide four forward speeds and four reverse speeds. Speed selections and direction selections are made manually by using transmission direction and speed control (10). The autoshift control will make speed selections and direction selections if the machine is in automatic mode.
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 (15) receives the operator input from transmission direction and speed control (10). The power train ECM signals the solenoid of the modulating valve (transmission clutch) for 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) (22) that are selected. The energized solenoid for the modulating valves (transmission clutch) will 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 (19), torque converter output speed sensor (21), transmission speed sensors (24) and (27) and transmission oil temperature sensor (23) .
The power train ECM also controls the following functions: neutral start, ride control, backup alarm, air heater, dual horsepower, secondary steering, parking brake interlock and transmission neutralizer.