HARNESS AS-CONTROL 2756979 - Caterpillar

Illustration 1 g02416361
Location of Power Train Components on the 770G (1) Oil cooler (2) Torque converter (3) Gear pump (4) Transmission (5) Drive shaft (6) Rear axle (7) Oil filterThe power train is made up of four basic systems. The following systems are the four systems:
Chassis Electronic Control Module
Torque Converter
Transmission
Differential and Final DrivesThe four basic systems have a hydraulic connection, an electrical connection, a magnetic connection, or a mechanical connection.The chassis electronic control module (chassis ECM) matches the transmission speed to the selected speed of the transmission shift lever. The chassis ECM gets information of the selected speed of operation through the electrical system. The chassis ECM activates the transmission hydraulic system and the torque converter hydraulic systems through the modulating valve solenoids for the transmission, and the modulating valve solenoid for the torque converter lockup clutch.The torque converter has a lockup clutch for direct drive and a one-way clutch for torque converter drive. The torque converter is fastened directly to the flywheel of the engine.The torque converter drives the transmission hydraulically, unless the lockup clutch is activated. When the lockup solenoid is activated, the lockup clutch is hydraulically engaged. The torque converter rotating housing is now mechanically connected to the output shaft of the torque converter. The drive shaft mechanically connects the torque converter to the transfer gears. The transfer gears are fastened directly to the transmission.The modulating valve solenoids for the transmission hydraulically activate the transmission hydraulic control valves. The control valves activate the transmission clutches which cause the mechanical connection to the transmission output shaft. The clutches in the transmission will not drive the transmission output shaft unless the torque converter is activated hydraulically or mechanically.The transmission has seven forward speeds and one reverse speed. The selection of speed is done manually in REVERSE, in NEUTRAL and in FIRST. The selection of SECOND through SEVENTH speeds is done automatically.Power is sent through the REVERSE gear in torque converter drive only. FIRST has both a torque converter drive and a direct drive. SECOND through SEVENTH speeds are direct drive with a short time of converter drive during transmission clutch engagement. The direct drive with a short time of converter drive enables smoother shifts. The transmission is fastened directly to the differential and bevel gear. The differential and bevel gear are fastened directly to the rear axle housing. The differential and bevel gear are also connected to the rear axle. The rear axle is connected to the wheels and final drives.After the transmission is connected to the torque converter, power flows from the engine through the torque converter and the transmission to the differential. The rear axles mechanically connect the differential to the final drives. The final drives are connected to the rear wheels. Power is then sent to the tires.Pressure oil that is used to engage the lockup clutch comes from the gear pump for the transmission and torque converter. Oil flows through the oil filter to the