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| Illustration 1 | g00308003 |
Power train hydraulic system schematic (1) Priority valve. (2) Breather. (3) Sump in torque converter housing. (4) Torque converter. (5) Torque converter outlet relief valve. (6) Oil cooler. (7) Transmission lubrication. (8) Orifice plate. (9) Drain to sump in bevel gear case. (10) Transmission oil pump. (11) Bevel gear case (power train oil tank). (12) Sump in transmission case. (13) Steering clutch and brake lubrication. (14) Hook control valve. (15) Steering and brake control valve. (16) Transmission oil filter. (17) Selector and pressure control valve. (A) Transmission charging section. (B) Steering clutch and brake lubrication section. (C) Transmission and torque converter scavenge section. | |
The hydraulic system for the power train uses a three-section oil pump (10). The pump is mounted on the front of the bevel gear case. The pump is driven by an auxiliary drive shaft from the engine. The bevel gear case is used as the power train oil tank. There are internal tubes that move oil to the pump and from the pump.
The first section of oil pump (10) is scavenge section (C) for the transmission/torque converter. This section takes oil from torque converter sump (3) and from transmission sump (12). This oil is returned to bevel gear case (11) .
The middle section of the pump is steering and brake lubrication section (B). This section takes oil from bevel gear case (11). This oil is sent to the steering clutches and the brakes for lubrication.
The third section on the oil pump is transmission charging section (A). This section takes oil from bevel gear case (11). Then, the oil is sent to transmission oil filter (16). Oil flows through the filter and to priority valve (1), steering and brake control valve (15), and hook winch control valve (14) .
Priority valve (1) makes sure that oil pressure is first available for the steering and brake control, for the hook winch control, and then for the transmission controls. Oil that flows through the transmission controls is used to engage the transmission clutches. This oil is also sent to torque converter (4). From the torque converter, oil flows through outlet relief valve (5) to oil cooler (6). Oil from the oil cooler flows to the lubrication circuits of the transmission. Then, the oil returns to the transmission sump.