Hearing the click of a solenoid or using a screwdriver to check that the solenoid coil is energized does not ensure that the spool of the solenoid modulating valve has shifted. The following test will determine if the spool of the solenoid modulating valve is shifting.
The direction clutch pressure taps and the speed clutch pressure taps are installed in the transmission clutch solenoid modulating valves. The transmission clutch solenoid modulating valves are located on the right side of the transmission beneath the cab.
| Required Tools | ||
| Part Number | Description | Quantity |
| 1U-5481 | Pressure Gauge Group | 1 |
| 1U-5482 | Pressure Adapter Group | 1 |
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Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. Prevent possible injury by performing the procedure that follows before working on the machine. |
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Before you start the test procedure, complete the following procedure:
- Start the engine.
- Park the machine on a smooth, level surface.
- Shift transmission direction switch (7) to the NEUTRAL position. Use transmission speed upshift control switch (8) or transmission speed downshift control switch (9) to place the transmission in any speed position.
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| Illustration 1 | g01312761 |
(7) Transmission direction control switch | |
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| Illustration 2 | g01316177 |
(8) Transmission speed upshift control switch (9) Transmission speed downshift control switch | |
- Lower the work tool to the ground.
- Engage the parking brake and stop the engine.
- Place blocks in front of the wheels and behind the wheels.
- Install the steering frame lock.
- Close the doors for the engine enclosure in order to provide proper operation of the cooling system.
- Allow only authorized personnel on the machine. Keep unauthorized personnel off the machine and in clear sight of the operator.
- If a new modulating valve was installed, start the engine and shift the transmission for at least 12 times into a speed or a direction that uses the new clutch solenoid modulating valve. Refer to table 2 in order to identify the clutches that are engaged for each direction and each gear. If a new modulating valve was not installed, proceed to the next step.
| Speed Range and Direction of the Machine | Energized Solenoids | Engaged Clutches |
| First Speed Forward | 2 and 5 | 1 and 6 |
| Second Speed Forward | 1 and 5 | 2 and 6 |
| Third Speed Forward | 2 and 4 | 1 and 4 |
| Fourth Speed Forward | 1 and 4 | 2 and 4 |
| Fifth Speed Forward | 1 and 6 | 2 and 5 |
| Neutral | 6 | 5 |
| First Speed Reverse | 3 and 5 | 3 and 6 |
| Second Speed Reverse | 3 and 4 | 3 and 4 |
| Third Speed Reverse | 3 and 6 | 3 and 5 |
Note: The third gear clutch might not engage in neutral during certain conditions.
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| Illustration 3 | g01287294 |
Transmission Clutch Solenoid Modulating Valves (1) The pressure tap for the number 2 clutch (Forward High) (2) The pressure tap for the number 1 clutch (Forward Low) (3) The pressure tap for the number 3 clutch (Reverse) (4) The pressure tap for the number 4 clutch (Second gear) (5) Number 6 clutch pressure tap (First gear) (6) The pressure tap for the number 5 clutch (Third gear) (7) Torque converter inlet pressure tap (8) Pressure tap for the main relief valve | |
- Install the correct hose assembly from 1U-5482 Pressure Adapter Group on pressure tap (1) through pressure tap (6). Attach the opposite end of the hose assembly to 1U-5481 Pressure Gauge Group .
- Engage the parking brake. Shift the transmission direction control switch to the NEUTRAL position. Start the engine and operate the engine at low idle.
- Depress the service brake pedal and hold the service brake pedal. Release the parking brake. Watch the pressure gauge and move the transmission direction control switch to the FORWARD position from the NEUTRAL position.
Shift through all of the gears. The pressure should raise to 2275 kPa (330 psi) for the gear that is selected. Two solenoids should be active for each selection. One solenoid should be active for speed and one solenoid should be active for direction.
- Perform Step 3 for all reverse speeds. The same rise in pressure should be noted in all reverse speeds.
If a pressure drop is noted, the solenoid and the related electrical circuit are functioning correctly.
If the pressure does not rise to 2415 kPa (350 psi) at high idle or 2275 kPa (330 psi) at low idle, use a screwdriver in order to check that the solenoid coil is energized. If the screwdriver is attracted to the solenoid coil, this indicates that the solenoid coil is energized. The problem is in the solenoid cartridge. The problem could be a bent solenoid stem, a screen that is dirty or plugged, or a spring that is weak or broken.
If the screwdriver does not indicate that the solenoid coil is energized, the problem is in the electrical circuit.
For additional information about troubleshooting the electrical system, refer to Testing and Adjusting, "Power Train Troubleshooting" and Schematic, "525C / 535C / 545C Wheel Skidder Electrical System" for the machine that is being serviced.