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| Illustration 1 | g00908031 |
Schematic for the Transmission Hydraulic System (1) Transmission hydraulic control relief valve (2) Torque converter (3) Torque converter outlet relief valve (if equipped) (4) Transmission oil filter (5) Modulating valve (transmission clutch) for the Number 1 clutch (6) Modulating valve (transmission clutch) for the Number 4 clutch (7) Modulating valve (transmission clutch) for the Number 2 clutch (8) Modulating valve (transmission clutch) for the Number 5 clutch (9) Modulating valve (transmission clutch) for the Number 3 clutch (10) Modulating valve (transmission clutch) 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 (B) P3 Torque converter inlet pressure tap (C) Torque converter outlet pressure tap (D) Sampling valve for the transmission oil (G) Number 1 clutch pressure tap (H) Number 4 clutch pressure tap (J) Number 2 clutch pressure tap (K) Number 5 clutch pressure tap (L) Number 3 clutch pressure tap (M) Number 6 clutch pressure tap (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), modulating valves (transmission clutch) (5-10), torque converter (2), torque converter inlet relief valve (12), torque converter outlet relief valve (3) 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. Transmission oil pump (11) pulls oil from oil sump (14). The oil flows through the suction screen and magnet (13). Oil is supplied to the pump inlet through a tube that is mounted to the pump inlet and the output transfer gear case. Pressurized oil exits the pump outlet and flows 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. Transmission hydraulic control relief valve (1) receives some of the pressurized oil flow. Modulating valves (5-10) receive some of the pressurized oil flow.
Modulating valves (5-10) are mounted on the top of the transmission under the cab. The six transmission clutches have an individual modulating valve (5-10). In order to move the machine, a direction clutch solenoid and a speed clutch solenoid must be energized. The modulating valves (5-10) are used to directly modulate the oil pressure that is sent to each individual clutch. The leakage oil from the clutches and the return oil flows to the bottom of the transmission. The nonenergized modulating valves (5-10) return the oil flow 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 flows to modulating valves (5-10). Oil flows into transmission hydraulic control relief valve (1) at a maximum pressure of 2930 kPa (425 psi). The oil pressure overcomes the spring force of transmission hydraulic control relief valve (1). Torque converter inlet oil then flows to torque converter (2) at 550 kPa (80 psi).
Torque converter inlet relief valve (12) limits P3 torque converter inlet oil to a maximum pressure of 900 ± 70 kPa (130 ± 10 psi). Torque converter inlet relief valve (12) is located in the torque converter housing. Transmission hydraulic control relief valve (1) is located above the torque converter inlet relief valve. Transmission hydraulic control relief valve (1) must be removed in order to attain access to the torque converter inlet relief valve.
The outlet oil from torque converter (2) flows to torque converter outlet relief valve (3). Torque converter outlet relief valve (3) (if equipped) maintains the oil pressure inside the torque converter at a specific rate. Torque converter outlet relief valve (3) (if equipped) maintains the oil pressure inside the torque converter at 415 ± 140 kPa (60 ± 20 psi). The oil flows from the torque converter outlet relief valve to oil cooler (16) .
Oil cooler (16) is located on the right side of the engine. After the oil has been cooled, the oil flows to the transmission. The oil provides lubrication to the transmission and cooling to the transmission. The oil flows through internal passages in the transmission to the bearings, the gears, and the clutches. The oil then flows to the bottom of the transmission. The oil then flows to oil sump (14) in the bottom of the output transfer gear case.