RETAINER-PIN 3691557 - Caterpillar

Illustration 1 g02505616
Power from diesel engine (1) is sent from the flywheel to the torsional coupling (2) to rear pump drive (3). From the rear pump drive, power flows in two directions.In one direction, power flows through auxiliary drive shafts (10) to front pump drive (12). The front pump drive drives the three main implement pumps. The front pump drive also drives the lubrication pump for the front pump drive, the pilot pumps for the implements, and the implement cooling pumps.ReferenceFor information on the front pump drive and the implement pumps, refer to Systems Operation, "994H Wheel Loader Hydraulic System".From the rear pump drive, power also flows to torque converter (4). The torque converter has an impeller clutch and a lockup clutch. The lockup clutch is used to provide direct drive capability. Inside the torque converter, an impeller is fastened to the hub of a clutch that is hydraulically activated. The impeller clutch allows a controlled reduction in the torque converter in order to vary the torque output of the torque converter.The impeller clutch is controlled by the electronic control module (ECM) for the power train. The ECM receives a signal from the left pedal and the rimpull select switch. The left pedal is used to vary the amount of torque converter output in order to control the amount of wheel slippage. When the torque converter output is reduced, more power is available for the implement system.The lockup clutch is controlled by the electronic control module (ECM) for the power train and the lockup clutch switch inside the cab. The electronic control module determines when the lockup clutch is engaged. The lockup clutch will only engage when the lockup clutch switch is in the enabled position. For information on the impeller clutch and the lockup clutch, refer to Systems Operation, "Torque Converter (Lockup)" in this manual.A gear on the torque converter housing is used to drive pump (16) which supplies the power train hydraulic system with oil. The oil is pulled from the reservoir that is located in the bottom of the output transfer gears. The oil is filtered through magnetic screens (19) before the oil reaches the pump. The oil is then filtered after the pump before the oil travels to the remainder of the power train hydraulic system.Power from the torque converter is sent through input drive shaft (7) to input transfer gears (8). The input transfer gears drive the input shaft of transmission (11) .Five clutches in the transmission, which are activated hydraulically, provide three forward speeds and three reverse speeds. Speed and direction are selected by using the STIC.The power leaves the transmission output shaft and travels through the output transfer gears (18). The output transfer gears lower the output speed and the power is transferred in two directions.Power travels through drive shaft (17) to the rear differential and bevel gear (26). Power also travels to the front differential and bevel gear (27) through the articulation joint using drive shaft slip joint (20) and universal