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| Illustration 1 | g00666034 |
Schematic for the Transmission Hydraulic System (1) Transmission hydraulic control relief valve (2) Torque converter (3) Flow control orifice (4) Transmission oil filter (5) Clutch solenoid modulating valve for the Number 1 clutch (6) Clutch solenoid modulating valve for the Number 4 clutch (7) Clutch solenoid modulating valve for the Number 2 clutch (8) Clutch solenoid modulating valve for the Number 5 clutch (9) Clutch solenoid modulating valve for the Number 3 clutch (10) Clutch solenoid modulating valve for the Number 6 clutch (11) Transmission oil pump (12) Torque converter inlet relief valve (13) Suction screen and magnet (14) Oil sump (15) Transmission lubrication (16) Oil cooler (A) Pump pressure tap at the transmission hydraulic control relief valve (B) P3 Torque converter inlet pressure tap (C) Torque converter outlet pressure tap (D) Pump pressure tap at the oil filter (F) Sampling valve for the transmission oil (G) Pressure tap for the Number 1 clutch (H) Pressure tap for the Number 4 clutch (J) Pressure tap for the Number 2 clutch (K) Pressure tap for the Number 5 clutch (L) Pressure tap for the Number 3 clutch (M) Pressure tap for the Number 6 clutch (N) Transmission lubrication pressure tap | |
The transmission hydraulic system consists of the following components: suction screen and magnet (13), transmission oil pump (11), transmission oil filter (4), transmission hydraulic control relief valve (1), clutch solenoid modulating valves (5-10), torque converter (2), torque converter inlet relief valve (12) and oil cooler (16) .
The bottom of the output transfer gear case contains oil sump (14). Transmission oil pump (11) is a one-section gear type pump. Transmission oil pump (11) is a positive displacement pump. Transmission oil pump (11) supplies oil to the transmission hydraulic system by pulling oil from oil sump (14). The oil flows through suction screen and magnet (13). Oil is supplied to the pump inlet through a tube that is mounted to the pump inlet and to the output transfer gear case. Pressurized oil flows from the pump outlet to externally mounted transmission oil filter (4). Pressurized oil flows from transmission oil filter (4) through an external hose to the torque converter housing. Pressurized oil then flows through internal passages in the torque converter housing to transmission hydraulic control relief valve (1). Pressurized oil also flows from the torque converter housing to clutch solenoid modulating valves (5-10) through the internal passages in the transmission housing.
Clutch solenoid modulating valves (5-10) are mounted on the top of the transmission under the cab. There is one clutch solenoid modulating valve (5-10) for each of the six transmission clutches. In order to move the machine, a direction clutch solenoid and a speed clutch solenoid must be energized. Clutch solenoid modulating valves (5-10) are used to directly modulate the oil pressure that is sent to each individual clutch. The clutch leakage oil and the return oil flows to the bottom of the transmission. All oil from nonenergized clutch solenoid modulating valves (5-10) flows to the bottom of the transmission. The oil then flows to oil sump (14) in the bottom of the output transfer gear case.
Transmission hydraulic control relief valve (1) controls the pressure of the oil that is supplied to clutch solenoid modulating valves (5-10). Oil flows into transmission hydraulic control relief valve (1) at a maximum pressure of 2897 kPa (420 psi). The oil pressure overcomes the spring force of transmission hydraulic control relief valve (1). The torque converter inlet oil flows to torque converter (2) at 550 kPa (80 psi).
Torque converter inlet relief valve (12) limits P3 torque converter inlet oil pressure to a maximum of 900 ± 70 kPa (130 ± 10 psi). Torque converter inlet relief valve (12) is located in the torque converter housing beneath transmission hydraulic control relief valve (1). Transmission hydraulic control relief valve (1) must be removed in order to access the torque converter inlet relief valve. The outlet oil from torque converter (2) flows to oil cooler (16) .
Oil cooler (16) is located in the bottom tank of the radiator. After the oil has been cooled, the oil flows to the transmission. The oil provides lubrication and cooling to the transmission. The oil flows through internal passages in the transmission to the bearings, to the gears and to the clutches. The oil then flows to the bottom of the transmission and to oil sump (14) in the bottom of the output transfer gear case.