Hearing the click of a solenoid or using a screwdriver to check that the solenoid coil is energized does not ensure that the solenoid plunger has shifted. The following test will determine if the solenoid plunger is shifting.
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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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The input drive shaft rotates between the torque converter and the transmission whenever the engine is running. Contact with the rotating shaft can result in personal injury or death. The rotating shaft is located under the door assemblies that are behind the machine cab. Do not allow personnel into the area behind the cab when the machine is running. |
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Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Caterpillar Tools and Shop Products Guide" for tools and supplies suitable to collect and contain fluids on Caterpillar products. Dispose of all fluids according to local regulations and mandates. |
- Move the machine to a smooth, horizontal location that is away from operating machines and away from personnel.
Note: Permit only one operator on the machine. Keep all other personnel away from the machine or in the operator's sight.
- Move the STIC transmission direction control switch to the NEUTRAL position.
- Lower the work tool to the ground.
- Engage the parking brake.
- Place blocks in front of the wheels and behind the wheels.
- Install the steering frame lock.
- Allow only authorized personnel on the machine. Keep unauthorized personnel off the machine and in clear sight of the operator.
Show/hide table
Table 1 Speed Range and Direction Energized Solenoids Engaged Clutches Third Speed Forward 3 and 2 3 and 2 Second Speed Forward 4 and 2 4 and 2 First Speed Forward 5 and 2 5 and 2 Neutral 3 3 First Speed Reverse 5 and 1 5 and 1 Second Speed Reverse 4 and 1 4 and 1 Third Speed Reverse 3 and 1 3 and 1
- Install a hose and a 4130 kPa (600 psi) pressure gauge on pressure tap (G) .
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| Illustration 1 | g00740501 |
Transmission (D) Torque Converter Inlet Pressure Tap P3. (E) Speed Clutch Pressure Tap P1. (G) Direction Clutch Pressure Tap P2. (J) Transmission Lubrication Pressure Tap. | |
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| Illustration 2 | g00740506 |
Transmission Selector and Pressure Control Valve The transmission selector and pressure control valve is on the top of the transmission. The transmission cover is removed. (K) Speed clutch pressure tap P1. (L) Plug for Load Piston LP. | |
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| Illustration 3 | g00439183 |
Location of Solenoid Valves (1) Number 1 solenoid (Reverse). (2) Number 2 solenoid (Forward). (3) Number 3 solenoid (Third speed). (4) Number 4 solenoid (Second speed). (5) Number 5 solenoid (First speed). | |
- Engage the parking brake. Move the STIC transmission direction control switch to the NEUTRAL position. Start the engine and operate the engine at low idle.
- Depress the right service brake pedal and hold the right service brake pedal. Release the parking brake. Press the downshift gear speed switch until the transmission is in first speed. Watch the pressure gauge and move the STIC transmission direction control switch from the NEUTRAL position to the FORWARD position.
The needle on the pressure gauge should drop. Then, the needle will return to the original pressure reading. With the transmission in the forward direction, press the upshift gear speed switch through the remaining forward speed positions and return the switch to first speed. The same pressure drop should be noted in all speeds. This checks the operation of all the speed clutches.
- Move the STIC transmission direction control switch to the NEUTRAL position.
- Depress the right service brake pedal and hold the right service brake pedal. Release the parking brake. Press the downshift gear speed switch until the transmission is in first speed. Move the STIC transmission direction control switch to the FORWARD position.
Watch the pressure gauge and move the STIC transmission direction control switch to the REVERSE position. The needle on the pressure gauge should drop. Then, the needle will return to the original pressure reading. Now, move the direction control switch to the FORWARD position. The same pressure drop should be observed. This checks the operation of both direction clutches.
- Move the STIC transmission direction control switch to the NEUTRAL position.
If a pressure drop is noted, the solenoid and the related electrical circuit are functioning.
If a pressure drop is not noted, use a screwdriver 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.
Reference: For additional information on electrical system troubleshooting, refer to the Service Manual module for Systems Operation, Testing and Adjusting, RENR2522, "Power Train Electronic Control System".