PANEL AS 3213357 - Caterpillar

General Information
The power train is a hydrostatic system. The system shares the hydraulic tank with the implement system and the steering system.
Illustration 1 g03797806
Typical of a 906, 907, and 908 20kph
(1) Front axle
(2) Parking brake
(3) Drive shaft
(4) Accelerator pedal
(5) Charge pump
(6) Joystick with forward, neutral, and reverse switch
(7) Hydraulic oil tank
(8) Hydraulic oil filter
(9) Rear axle
(10) Hydrostatic piston pump
(11) Transmission
(12) Hydrostatic piston motor
Illustration 2 g03797881
Typical of a 906, 907, and 908 35kph
(1) Front axle
(2) Parking brake
(3) Drive shaft
(4) Accelerator pedal
(5) Charge pump
(6) Joystick with forward, neutral, and reverse switch
(7) Hydraulic oil tank
(8) Hydraulic oil filter
(9) Rear axle
(10) Hydrostatic piston pump
(11) Transmission
(12) Hydrostatic piston motor The power train is a hydrostatic system. The engine drives piston pump (10) which then drives piston motor (12). The hydrostatic system is a closed loop. Oil is continuously pumped between piston pump (10) and piston motor (12).The charge pump (5) charges the system at start-up and the charge pump provides makeup oil. Oil is directed by charge pump (5) through filter group (8). Filter group (8) filters the oil before entering piston pump (10) and piston motor (12). The charge pump (5) also provides the source for signal pressure in order to control pump (10). The signal pressure is controlled electronically in order to vary proportionally to the engine speed. This relationship is handled electronically. As the engine speed becomes higher, the signal pressure will become higher.The piston motor (12) is mounted to a transmission (11). The transmission (11) allows one piston motor to turn both the front wheels and the rear wheels. Power from transmission (11) is transferred to front axle (1) through drive shaft (3). The rear axle (9) receives power directly from transmission (11). The parking brake (2) is mounted on the drive shaft near the front differential. The service brakes are mounted in the axle and are oil immersed.The direction of the machine is controlled by the direction control switch that is located in the cab on joystick (6). The speed of the machine is controlled by accelerator pedal (4). If the machine is equipped with a creeper control, the speed of the machine can also be controlled by the creeper control.The machine will shift to NEUTRAL, if the parking brake lever is engaged and the direction control switch is in the FORWARD or REVERSE position. In order to get the machine to move, the direction control switch must be moved to NEUTRAL and the parking brake must be disengaged. Then, the direction control switch must be moved to the desired direction.Two Speed (If Equipped)
The speed range selection switch on the joystick will change between Speed Range 1 (SR1) and Speed Range 2 (SR2). On machines with an optional speeder transmission, a transmission high/low gear selection switch is provided on the right-hand console. This switch shifts the transmission between high gear and low gear. When high gear is selected, the machine will operate in Speed Range H (SRH). When low gear is selected, the machine will operate in SR1 or SR2