The solenoid control valve directs the pressurized oil to either the forward clutch pack or to the reverse clutch pack. In the NEUTRAL position, clutch pressure is dumped back to the transmission case. The reverse solenoid of the solenoid control valve for the transmission is electrically connected with the backup alarm switch. The backup alarm switch activates the backup alarm.
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| Illustration 1 | g03647396 |
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| Illustration 2 | g03647397 |
Neutralizer controls | |
The neutralizer switch is located on either the left side of the dash or the loader control lever. The neutral lock switch on the left side of the dash disables all transmission solenoids. The neutralizer switch that is located on the loader control lever disengages the direction control solenoids.
If the vehicle is turned off, and the direction control lever is left in the FORWARD position or the REVERSE position, the vehicle will not be able to start until the direction control lever is returned to the NEUTRAL position.
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| Illustration 3 | g03647398 |
The solenoids that are located in the solenoid control valve are electronically actuated. The solenoids are actuated by the direction control lever that is on the steering wheel column.
When the solenoid control valve is de-energized, the centering springs center the spool, which blocks the oil flow from the transmission pump. The oil pressure in the direction clutch decreases and the direction clutch disengages when oil flow to the transmission is blocked. When the transmission solenoid is energized, the oil passages to the transmission are opened. The energized solenoid permits the filling of one of the direction clutches. The energized solenoids also allow the pressure to build up in the transmission.
Transmission Operation
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| Illustration 4 | g03086957 |
The transmission hydraulic system in NEUTRAL (1) Oil filter with bypass (2) System relief valve (3) Transmission solenoid valve (4) Reverse clutch pack (5) Pressure tap for reverse clutch (6) Pressure tap for forward clutch (7) Forward clutch pack (8) Pressure tap for torque converter inlet (9) Inlet relief valve for torque converter (10) Torque converter (11) Pressure tap for torque converter outlet (12) Oil Cooler (13) Pressure tap for lubrication and cooling (14) Transmission lubrication system (15) Oil reservoir (16) Suction screen (17) Oil pump (18) Pressure tap for pump (AA) Pump supply oil (BB) Converter inlet oil (CC) Lubrication oil (DD) Tank oil | |
When the engine is running, oil pump (17) pulls oil from reservoir (15) through suction screen (16) to the pump. The oil pump sends the oil through filter (1) and to the control solenoid valve for the transmission (3) .
With the direction control lever in the NEUTRAL position, oil flow is blocked by the solenoid control valve. The forward clutch pack nor the reverse clutch pack can be pressurized. The passages for the clutch oil are open to the drain.
This allows oil that is not needed by the transmission circuit to flow through the system relief valve to the torque converter.
Torque converter inlet relief valve (9) controls maximum pressure to the torque converter in order to prevent damage during cold starts. Torque converter pressure is maintained in the torque converter by the restrictions that are created by the oil cooler and the oil lines that are leaving the torque converter.
Run the Engine (Forward)
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| Illustration 5 | g03086976 |
The transmission hydraulic system in FORWARD (1) Oil filter with bypass (2) System relief valve (3) Transmission solenoid valve (4) Reverse clutch pack (5) Pressure tap for reverse clutch (6) Pressure tap for forward clutch (7) Forward clutch pack (8) Pressure tap for torque converter inlet (9) Inlet relief valve for torque converter (10) Torque converter (11) Pressure tap for torque converter outlet (12) Oil Cooler (13) Pressure tap for lubrication and cooling (14) Transmission lubrication system (15) Oil reservoir (16) Suction screen (17) Oil pump (18) Pressure tap for pump (AA) Pump supply oil (BB) Converter inlet oil (CC) Lubrication oil (DD) Tank oil | |
When the direction control lever on the steering wheel column is moved to the FORWARD position, the forward solenoid of the solenoid valve (3) is electrically activated. The electrical activation of the forward solenoid overrides the centering spring. The spool will then move. Pressurized oil will be able to flow to the forward clutch pack (7) .
An orifice within the control solenoid valve establishes a constant flow and pressure of oil to the forward clutch pack. This allows oil that is not needed by the transmission circuit to flow to the torque converter.
The FORWARD position directs oil to the forward clutch pack. The reverse clutch oil passage is open to the drain. Oil fills the forward clutch pack. The pressurized oil will engage the forward clutch pack.
When the forward clutch pack obtains maximum system pressure, the relief valve (2) opens. The relief valve helps maintain maximum system pressure to the forward clutch pack.
When relief valve (2) is closed, a bypass orifice within the relief valve still permits the flow of oil to the torque converter at low idle for lubrication and cooling purposes.
Run the Engine (Reverse)
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| Illustration 6 | g03086978 |
The transmission hydraulic system in REVERSE (1) Oil filter with bypass (2) System relief valve (3) Transmission solenoid valve (4) Reverse clutch pack (5) Pressure tap for reverse clutch (6) Pressure tap for forward clutch (7) Forward clutch pack (8) Pressure tap for torque converter inlet (9) Inlet relief valve for torque converter (10) Torque converter (11) Pressure tap for torque converter outlet (12) Oil Cooler (13) Pressure tap for lubrication and cooling (14) Transmission lubrication system (15) Oil reservoir (16) Suction screen (17) Oil pump (18) Pressure tap for pump (AA) Pump supply oil (BB) Converter inlet oil (CC) Lubrication oil (DD) Tank oil | |
When the direction control lever on the steering wheel column is moved to the REVERSE position, the reverse solenoid of the solenoid valve (3) is electrically activated. The electrical activation of the reverse solenoid overrides the centering spring. The spool will then move. Pressurized oil will be able to flow to the reverse clutch pack (4) .
An orifice within the control solenoid valve establishes a constant flow and pressure of oil to the reverse clutch pack. This allows oil that is not needed by the transmission circuit to flow to the torque converter.
The REVERSE position directs oil to the reverse clutch pack. The forward clutch oil passage is open to the drain. Oil fills the reverse clutch pack. The pressurized oil will engage the reverse clutch pack.
When the reverse clutch pack obtains maximum system pressure, the relief valve (2) opens. The relief valve helps maintain maximum system pressure to the reverse clutch pack.
When relief valve (2) is closed, a bypass orifice within the relief valve still permits the flow of oil to the torque converter at low idle for lubrication and cooling purposes.