PL72, PL83 and PL87 Pipelayers Caterpillar

Transmission Controls

Illustration 1	g03664889
View from the top side of the transmission (1) Transmission Harness 17 Pin Connector (2) Oil Supply Tube (3) Clutch Pressure Taps (4) Harness leading to Transmission Output Speed (TOS) Sensors (5) Electronic Main Relief Valve (eMRV) (6) Clutch Drain Valve (x 2) (7) Oil Return Tube (8) Transmission Clutch Control Valve (CLUTCH #1, REVERSE Direction) (9) Transmission Clutch Control Valve (CLUTCH #2, FORWARD Direction) (10) Transmission Clutch Control Valve (CLUTCH #4, SECOND Speed) (11) Transmission Clutch Control Valve (CLUTCH #5, FIRST Speed) (12) Transmission Clutch Control Valve (CLUTCH #3, THIRD Speed)

Problem List

• " Operate in Any Gear"

• "Harsh Shifting of Transmission"

• "The Transmission Does Not Change Gears but the Machine Moves"

• "The Machine Makes an Abrupt Stop When You Shift into the NEUTRAL Position"

• "The Transmission Operates in FORWARD Gears Only"

• "The Transmission Operates in REVERSE Gears Only"

• "The Transmission Does Not Operate In FIRST GEAR FORWARD or FIRST GEAR REVERSE"

• "The Transmission Does Not Operate In SECOND GEAR FORWARD or SECOND GEAR REVERSE"

• "The Transmission Does Not Operate In THIRD GEAR FORWARD or THIRD GEAR REVERSE"

The Transmission Does Not Operate in Any Gear

1. Use the Information Display in to check the FNR signal from the transmission lever.

   1. Press the menu button.

   2. Arrow down to "Machine Status"

   3. Select "Powertrain" from the menu displayed.

   4. From the "Power Train" menu, Look for the following parameters:.
      • "DirSelPosSnsr#1"

      • "DirSelPosSnsr#2"

      Expected Results

      Show/hide table

      Table 2

      FORWARD	85 ± 5%
      NEUTRAL	50 ± 10%
      REVERSE	13 ± 7%

      Results

      • OK: The transmission lever is tolerance. Proceed to Step 2.

        
        

      • NOT OK: Contact the technical communicator for your Dealer for possible consultation with Caterpillar.

2. Operate the machine.

   The two primary causes of this symptom are the transmission and the brakes. This step guides the diagnosis of the problem to the brakes or to the transmission.
   

   Note: Disable enhanced autoshift prior to troubleshooting the transmission.

   1. Start the engine.

   2. Operate the engine at high idle.

   3. Attempt to operate the machine. Shift the transmission into third gear forward. Observe the engine speed during shifts.

      Results

      • The engine speed decreases. The engine is near stall condition during shifts.

      Results

      • NEAR STALL: Proceed to Step 3.

      • NO SIGNIFICANT DECREASE: The engine speed does not decrease significantly. Therefore, check the transmission first. Proceed to Step 4.

Show/hide table

Personal injury can result if the machine moves while testing. If the machine begins to move during test, reduce the engine speed immediately and engage the parking brake.

3. Check the brake pressure.
   

   Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Steering Clutch and Brake Pressure - Test"

   Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Steering Clutch and Brake Pressure - Test"

   Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Steering Clutch and Brake Pressure - Test"

   Expected Results

   • The pressure is correct.

   Results

   • OK: The brake pressure is correct but the original problem is not resolved. Therefore, the transmission is the probable cause of the problem. Proceed to Step 5.

   • NOT OK: Proceed to Step 4.

4. Follow the procedure in this reference.

   Refer to "The Brake Does Not Release" in this module under Troubleshooting, "Brake Troubleshooting".

   Results

   • REPAIRED OK: Stop.

   • NOT OK: Proceed to Step 8.

5. Follow the procedure in this reference.

   Refer to "The Transmission Clutch Is Engaged and the Clutch Does Not Release" in this module under Troubleshooting, "Transmission Clutch Troubleshooting".

   Results

   • REPAIRED OK: Stop.

   • NOT OK: Proceed to Step 8.

6. Eliminate other possible causes.

   The condition can be caused by several other components. Eliminate the following components as possible causes of the problem.

   1. Torque divider (converter)

   2. Transfer or bevel gears

   3. Final drives

   4. Drive shaft

   5. Axle shafts

      Expected Results

      • The original problem is resolved.

      Results

      • OK: Stop.

      • NOT OK: The cause of the problem is unknown. Use the information from the original problem to troubleshoot.

7. Follow the procedure in this reference.

   Refer to "The Transmission Clutch Does Not Engage" in this module under Troubleshooting, "Transmission Clutch Troubleshooting".

   Results

   • REPAIRED OK: Stop.

   • NOT OK: The cause of the problem is uncertain. Call technical support with the information that has been gathered.

8. Inspect the transmission.

   1. Disassemble the transmission. Inspect the transmission for damage.
      

      Reference(PL72 LRC) Disassembly and Assembly, UENR4144, "Transmission"

      Reference(PL72 HRC) Disassembly and Assembly, UENR4143, "Transmission"

      Reference(PL83 LRC) Disassembly and Assembly, UENR4141, "Transmission"

      Reference(PL83 HRC) Disassembly and Assembly, UENR4139, "Transmission"

      Reference(PL87 LRC) Disassembly and Assembly, UENR4142, "Transmission"

      Reference(PL87 HRC) Disassembly and Assembly, UENR4140, "Transmission"

   2. Replace components or repair components that are not functioning correctly, if necessary.

   3. Check the operation of the machine for the original problem.

      Expected Results

      • The original problem is resolved.

      Results

      • OK: Stop.

      • NOT OK: The cause of the problem is uncertain. Call technical support with the information that has been gathered.

Harsh Shifting of Transmission

Follow this procedure if harsh shifts occur. Harsh shifting can occur when the transmission shifts into certain gears or when the transmission shifts from certain gears.

1. Operate the machine.

   1. Operate the machine. Determine the shift or shifts that are harsh.

   2. Determine the clutches that are used. Refer to Table 1 in "Transmission Controls" in this topic. The table shows the clutches that are used for the corresponding gears.

      Expected Results

      • One clutch is common for all harsh shifts.

      Results

      • YES: Proceed to Step 4.

      • NO: Proceed to Step 2.

2. Check the system pressure.
   

   Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Relief Valve (Transmission) - Test and Adjust"

   Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Relief Valve (Transmission) - Test and Adjust"

   Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Relief Valve (Transmission) - Test and Adjust"

   Expected Results

   The system pressure is correct.
   

   Results:

   • OK: Proceed to Step 5.

   • NOT OK: The cause of the problem may be the adjustment of the main relief valve. The main relief valve maintains the system pressure in the control section of the power train oil pump. Proceed to Step 3.

3. Follow the procedure in this reference.

   Refer to "System Pressure Is Low" in this module under Troubleshooting, "Oil Pressure Troubleshooting".

   Results

   • REPAIRED OK: Stop.

   • NOT OK: The cause of the problem is uncertain. Call technical support with the information that has been gathered.

4. Calibrate the transmission modulating valves.

   1. Calibrate the transmission modulating valves.
      

      Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Calibration" for the appropriate calibration procedure.

      Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration" for the appropriate calibration procedure.

      Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration" for the appropriate calibration procedure.

   2. Check the operation of the machine for the original problem.

      Expected Results

      • The original problem is resolved.

      Results

      • OK: Stop.

      • NOT OK: Proceed to Step 5.

5. Replace the transmission modulating valve.

   1. Replace the modulating valves for the transmission clutches that were identified in Step 1.b .

   2. Calibrate the transmission modulating valves.
      

      Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Calibration" for the appropriate calibration procedure.

      Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration" for the appropriate calibration procedure.

      Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration" for the appropriate calibration procedure.

   3. Check the operation of the machine for the original problem.

      Expected Results

      • The original problem is resolved.

      Results

      • OK: Stop.

      • NOT OK: Disassemble the transmission and inspect the transmission for failure. Repair the components and/or replace the components, if necessary. Check the operation of the machine for the original problem.

      
      

      Reference(PL72 LRC) Disassembly and Assembly, UENR4144, "Transmission"

      Reference(PL72 HRC) Disassembly and Assembly, UENR4143, "Transmission"

      Reference(PL83 LRC) Disassembly and Assembly, UENR4141, "Transmission"

      Reference(PL83 HRC) Disassembly and Assembly, UENR4139, "Transmission"

      Reference(PL87 LRC) Disassembly and Assembly, UENR4142, "Transmission"

      Reference(PL87 HRC) Disassembly and Assembly, UENR4140, "Transmission"

The Machine Makes an Abrupt Stop When You Shift into the NEUTRAL Position

The machine functions correctly when the transmission is in gear. However, the machine stops when the transmission is placed in the NEUTRAL position.

1. Check for the symptom.

   1. Determine that the symptom is active.

   2. Follow this procedure only if the symptom is active.

      Results

      • ACTIVE: Proceed to Step 2.

      • NOT ACTIVE: The symptom is intermittent. Follow this procedure when the problem is active. Stop.

      Note: Check the Information Display for Transmission Lever, Direction Switches, Transmission Clutches, Brake, and Steering Diagnostic Trouble Codes. If any diagnostic codes are present, repair the cause of the diagnostic codes before proceeding.

2. Check the brake pedal.

   1. Inspect the brake pedal. Determine if the pedal is returning to the original position.

   2. Repair the components or replace the components, if necessary.
      

      Reference(PL72 HRC and LRC) Operation and Maintenance Manual, SEBU278, "Machine Adjustments"

      Reference(PL83 LRC and HRC) Operation and Maintenance Manual, SEBU256, "Machine Adjustments"

      Reference(PL87 LRC and HRC) Operation and Maintenance Manual, SEBU256, "Machine Adjustments"

   3. Check the operation of the machine for the original problem.

      Expected Results

      • The original problem is resolved.

      Results

      • OK: Stop.

      • NOT OK: Proceed to Step 3.

3. Check the brake pressure.
   

   Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Steering Clutch and Brake Pressure - Test"

   Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Steering Clutch and Brake Pressure - Test"

   Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Steering Clutch and Brake Pressure - Test"

   Expected Results

   • The pressure is correct.

   Results

   • OK: Proceed to Step 7.

   • NOT OK: Proceed to Step 4.

4. Check the system pressure.

   Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Relief Valve (Transmission) - Test and Adjust"

   Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Relief Valve (Transmission) - Test and Adjust"

   Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Relief Valve (Transmission) - Test and Adjust"

   Expected Results

   • The system pressure is correct.

   Results

   • OK: Proceed to Step 8.

   • NOT OK: The cause of the problem may be the adjustment of the main relief valve. The main relief valve maintains the system pressure in the control section of the power train oil pump. Proceed to Step 5.

5. Adjust the main relief valve.

   Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Relief Valve (Transmission) - Test and Adjust"

   Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Relief Valve (Transmission) - Test and Adjust"

   Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Relief Valve (Transmission) - Test and Adjust"

   Results

   • OK: Stop.

   • NOT OK: Proceed to Step 6.

6. Follow the procedure in this reference.

   Refer to "System Pressure Is Low" in this module under Troubleshooting, "Oil Pressure Troubleshooting".

   Results

   • REPAIRED OK: The system pressure is correct but the original problem exists. Proceed to Step 8.

   • NOT OK: The cause of the problem is uncertain. Call technical support with the information that has been gathered.

7. Follow the procedure in this reference.

   Refer to "The Transmission Clutch Is Engaged and the Clutch Does Not Release" in this module under Troubleshooting, "Transmission Clutch Troubleshooting".

   Results

   • REPAIRED OK: Stop.

   • NOT OK: The cause of the problem is uncertain. Call technical support with the information that has been gathered.

8. Follow the procedure in this reference.

   Refer to "The Brake Does Not Release" in this module under Troubleshooting, "Brake Troubleshooting".

   Results

   • REPAIRED OK: Stop.

   • NOT OK: The cause of the problem is uncertain. Call technical support with the information that has been gathered.

The Transmission Does Not Change Gears but the Machine Moves

Follow this procedure if the machine operates in both directions, but the machine only operates in a single gear.

1. Check the lockout control.

   1. Check the maximum track speed value in ET. The Caterpillar Electronic Technician ET service tool is required.

      Expected Results

      • Maximum speed is limited to 1.0 or less.

      Results

      • YES: The transmission does not operate in second or third gear because the machine speed is limited. STOP

      • NO: Proceed to Step 2.

2. Follow the procedure in this reference.

   Refer to "The Transmission Clutch Is Engaged and the Clutch Does Not Release" in this module under Troubleshooting, "Transmission Clutch Troubleshooting".

   Results

   • REPAIRED OK: Stop.

   • NOT OK: Proceed to Step 3.

3. Check the switches.

   1. Check the operation of the up shift switch. Check the operation of the down shift switch.

   2. Repair the components and/or replace the components, if necessary.

   3. Check the operation of the machine for the original problem.

      Expected Results

      • The original problem is resolved.

      Results

      • OK: Stop.

      • NOT OK: The cause of the problem is uncertain. Call technical support with the information that has been gathered.

The Transmission Operates in FORWARD Gears Only

Follow this procedure if the machine shifts freely between all forward gears. However, the machine does not move when the transmission is shifted into any reverse gears.

1. Check the Information Display for the following Diagnostic Trouble Codes:
   • 1401-5 Transmission Reverse Clutch: Current Below Normal

   • 1401-6 Transmission Reverse Clutch: Current Above Normal

   • 1402-3 Transmission Forward Clutch: Voltage Above Normal

   Expected Results

   • There are no Diagnostic Trouble Codes displayed on the Information Display.

   Results

   • OK: There are no Diagnostic Trouble Codes displayed on the Information Display. Proceed to Step 2.

   • NOT OK: A Diagnostic Trouble Code is present on the Information Display. Repair the cause of the diagnostic code.
     Refer to Troubleshooting, "Solenoid Valve - Test "

2. Using Cat ET or the Information Display check for the following diagnostic codes:
   • 2993-3 Direction Selector Position Sensor #1: Voltage Above Normal

   • 2993-4 Direction Selector Position Sensor #1: Voltage Below Normal

   • 2993-8 Direction Selector Position Sensor #1 : Abnormal Frequency, Pulse Width, or Period

   • 2994-3 Transmission Selector Reverse Direction Switch: Not Responding Properly

   • 2994-4 Direction Selector Position Sensor #2: Erratic, Intermittent, or Incorrect

   • 2994-8 Direction Selector Position Sensor #2 : Abnormal Frequency, Pulse Width, or Period

   • 3527-12 Direction Selector : Bad Device or Component

   Note: If any 2993, 2994 or 3527 codes are present, the machine will only operate in the FORWARD direction. Repair the cause of the diagnostic codes before proceeding.

   For the 2993, 2994 or 3527 codes refer to Troubleshooting, "Sensor Signal (PWM) - Test "
   

   1. Check the signal from the transmission lever with Cat ET.

   2. From the "Service" menu, use the arrow keys in order to select "System Status". Then press the "OK" button.

   3. From the "System Status" menu, use the arrow keys in order to select "Power Train". Then press the "OK" button.

   4. From the "Power Train" menu, use the arrow keys in order to select "Transmission Lever".

      Expected Results

      Show/hide table

      Table 3

      FORWARD	85 ± 5%
      NEUTRAL	50 ± 10%
      REVERSE	13 ± 7%

      Results

      • OK: The transmission lever is in calibration. Proceed to Step 3.

      • NOT OK: Perform the calibration for the FNR shifter sensors.

      Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Calibration"

      Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

      Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

3. Interchange the modulating valves.

   1. Interchange the transmission modulating valve for the No. 1 clutch with the transmission modulating valve for the No. 2 clutch.

   2. Determine whether the problem follows the valve.

      Results

      • FOLLOWS: Proceed to Step 5.

      • DOES NOT FOLLOW: Proceed to Step 4.

4. Restore the modulating valves.

   1. Restore the modulating valves to the original locations.

   2. Note the suspect valve.

   3. Operate the machine under normal conditions.

      Expected Results

      • The original problem is resolved.

      Results

      • OK: An obstruction in the control valve may have been displaced during the procedure. Change the oil. Change the oil filter elements and clean the screens. Calibrate the transmission modulating valves.

      Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Calibration"

      Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

      Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

      • NOT OK: Proceed to Step 6.

5. Replace the transmission modulating valve.

   1. Replace the modulating valves for the transmission clutches that were identified in Step 3.b .

   2. Calibrate the transmission modulating valves.
      

      Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Calibration"

      Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

      Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

   3. Check the operation of the machine for the original problem.

      Expected Results

      • The original problem is resolved.

      Results

      • OK: Stop.

      • NOT OK: perform the following tests for the No. 1 clutch only. Proceed to Step 6.

6. Follow the procedure in this reference.

   Refer to "The Transmission Clutch Does Not Engage" in this module under Troubleshooting, "Transmission Clutch Troubleshooting".

   Results

   • REPAIRED OK: Calibrate the transmission modulating valves.

   Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Calibration"

   Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

   Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

   • NOT OK: The cause of the problem is uncertain. Call technical support with the information that has been gathered.

The Transmission Operates in REVERSE Gears Only

Follow this procedure if the machine shifts freely between all reverse gears. However, the machine does not move when the transmission is shifted into any forward gears.

1. Check the Information Display for the following Diagnostic Trouble Codes:
   • 1401-3 Transmission Reverse Clutch: Voltage Above Normal

   • 1402-5 Transmission Forward Clutch: Current Below Normal

   • 1402-6 Transmission Forward Clutch: Current Above Normal

   Expected Results

   • There are no Diagnostic Trouble Codes displayed on the Information Display.

   Results

   • OK: There are no Diagnostic Trouble Codes displayed on the Information Display. Proceed to Step 2.

   • NOT OK: A Diagnostic Trouble Code is present on the Information Display. Repair the cause of the diagnostic code.
     STOP

2. Using Cat ET or the Information Display check for the following diagnostic codes:
   • 2993-3 Direction Selector Position Sensor #1: Voltage Above Normal

   • 2993-4 Direction Selector Position Sensor #1: Voltage Below Normal

   • 2993-8 Direction Selector Position Sensor #1 : Abnormal Frequency, Pulse Width, or Period

   • 2994-3 Transmission Selector Reverse Direction Switch: Not Responding Properly

   • 2994-4 Direction Selector Position Sensor #2: Erratic, Intermittent, or Incorrect

   • 2994-8 Direction Selector Position Sensor #2 : Abnormal Frequency, Pulse Width, or Period

   • 3527-12 Direction Selector : Bad Device or Component

   Note: If any 2993, 2994 or 3527 codes are present, the machine will only operate in the FORWARD direction. Repair the cause of the diagnostic codes before proceeding.

   For the 2993, 2994 or 3527 codes refer to Troubleshooting, "Sensor Signal (PWM) - Test "

   1. Check the signal from transmission lever with Cat ET.

   2. From the "Service" menu, use the arrow keys in order to select "System Status". Then press the "OK" button.

   3. From the "System Status" menu, use the arrow keys in order to select "Power Train". Then press the "OK" button.

   4. From the "Power Train" menu, use the arrow keys in order to select "Transmission Lever".

      Expected Results

      Show/hide table

      Table 4

      FORWARD	85 ± 5%
      NEUTRAL	50 ± 10%
      REVERSE	13 ± 7%

      Results

      • OK: The transmission lever is in calibration. Proceed to Step 3.

      • NOT OK: Proceed to Testing and Adjusting, "Calibration" procedure in the service manual for your machine. Perform the calibration for the FNR shifter sensor.

3. Interchange the modulating valves.

   1. Interchange the transmission modulating valve for the No. 2 clutch with the transmission modulating valve for the No. 1 clutch.

   2. Determine whether the problem follows the valve.

      Expected Results

      • The original problem is resolved.

      Results

      • FOLLOWS: Proceed to Step 5.

      • DOES NOT FOLLOW: Proceed to Step 4.

4. Restore the modulating valves.

   1. Restore the transmission modulating valves to the original locations.

   2. Note the suspect valve.

   3. Operate the machine under normal conditions.

      Expected Results

      • The original problem is resolved.

      Results

      • OK: An obstruction in the valve may have been displaced during the procedure. Change the oil. Change the oil filter elements and clean the screens. Calibrate the transmission modulating valves.

      Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Calibration"

      Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

      Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

      • NOT OK: Proceed to Step 6.

5. Replace the transmission modulating valve.

   1. Replace the modulating valves for the transmission clutches that were identified in Step 3.b .

   2. Calibrate the transmission modulating valves.
      

      Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Calibration"

      Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

      Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

   3. Check the operation of the machine for the original problem.

      Expected Results

      • The original problem is resolved.

      Results

      • OK: Stop.

      • NOT OK: Perform the following tests for the No. 2 clutch only. Proceed to Step 6.

6. Follow the procedure in this reference.

   Refer to "The Transmission Clutch Does Not Engage" in this module under Troubleshooting, "Transmission Clutch Troubleshooting".

   Results

   • REPAIRED OK: Calibrate the transmission modulating valves.

   Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Calibration"

   Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

   Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

   • NOT OK: The cause of the problem is uncertain. Call technical support with the information that has been gathered.

The Transmission Does Not Operate in FIRST GEAR FORWARD or REVERSE

Show/hide table

Personal injury can result if the machine moves while testing. If the machine begins to move during test, reduce the engine speed immediately and engage the parking brake.

1. Check the Information Display for the following Diagnostic Trouble Codes:
   • 1405-5 Transmission Speed Clutch 1: Current Below Normal

   • 1405-6 Transmission Speed Clutch 1: Current Above Normal

   Expected Results

   • There are no Diagnostic Trouble Codes displayed on the Information Display.

   Results

   • OK: There are no Diagnostic Trouble Codes displayed on the Information Display. Proceed to Step 2.

   • NOT OK: A Diagnostic Trouble Code is present on the Information Display. Repair the cause of the diagnostic code.

   STOP

   Note: Check the Information Display 1403-3 Transmission Speed Clutch 3: Voltage Above Normal or 1404-3 Transmission Speed Clutch 2: Voltage Above Normal Diagnostic Trouble Codes. If any diagnostic codes are present, repair the cause of the diagnostic codes before proceeding.

2. Operate the machine.

   The following steps guide the diagnosis of the problem to the transmission clutches or to the transmission modulating valves.

   1. Start the engine.

   2. Operate the engine at high idle.

   3. Shift the transmission into FIRST GEAR FORWARD.

   4. Attempt to operate the machine.

      Expected Results

      • The engine speed decreases.

      Results

      • YES: Check the transmission clutches first. An engaged clutch could be preventing the transmission from operating properly. Proceed to Step 3.

      • NO: Check the pressure at the transmission modulating valve first. Proceed to Step 4.

3. Follow the procedure in this reference.

   Refer to "The Transmission Clutch Is Engaged and the Clutch Does Not Release" in this module under Troubleshooting, "Transmission Clutch Troubleshooting".

   Results

   • REPAIRED OK: Stop.

   • NOT OK: The cause of the problem is uncertain. Call technical support with the information that has been gathered.

Show/hide table

Personal injury can result if the machine moves while testing. If the machine begins to move during test, reduce the engine speed immediately and engage the parking brake.

4. Interchange the modulating valves.

   1. Interchange the transmission modulating valve for the No. 5 clutch (first gear) with the transmission modulating valve for the No. 4 clutch (second gear).

   2. Determine whether the problem follows the valve.

      Results

      • FOLLOWS VALVE: Proceed to Step 5.

      • DOES NOT FOLLOW: Proceed to Step 6.

5. Replace the modulating valve.

   1. Replace the suspect transmission modulating valve.

   2. Calibrate the transmission modulating valves.
      

      Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Calibration"

      Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

      Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

   3. Check the operation of the machine for the original problem.

      Expected Results

      • The original problem is resolved.

      Results

      • OK: Stop.

      • NOT OK: Perform the following tests for only the No. 5 clutch. Proceed to Step 7.

6. Restore the modulating valve.

   1. Restore the transmission modulating valves to the original locations.

   2. Operate the machine under normal conditions.

      Expected Results

      • The original problem is resolved.

      Results

      • OK: An obstruction in the valve may have been displaced during the procedure. Change the oil. Change the oil filter elements and clean the screens. Calibrate the transmission modulating valves.

      Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Calibration"

      Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

      Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

      • NOT OK: Perform the following tests for only the No. 5 clutch. Proceed to Step 7.

7. Follow the procedure in this reference.

   Refer to "The Transmission Clutch Does Not Engage" in this module under Troubleshooting, "Transmission Clutch Troubleshooting".

   Results

   • REPAIRED OK: Calibrate the transmission modulating valves.

   Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Calibration"

   Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

   Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

   • NOT OK: The cause of the problem is uncertain. Call technical support with the information that has been gathered.

The Transmission Does Not Operate in SECOND GEAR in FORWARD or REVERSE

1. Check lockout control.

   1. Check the track speed limit value to determine whether the gear is available. The Caterpillar Electronic Technician ET service tool is required.

      Expected Results

      • Maximum track speed in FORWARD and REVERSE is limited to less than 2.0.

      Results

      • YES: The transmission does not operate in SECOND GEAR and THIRD GEAR because SECOND GEAR and THIRD GEAR are locked out. Stop.

      • NO: Proceed to Step 2.

2. Operate the machine.

   The probable cause of the problem is the transmission or the brakes. The following step helps you determine a starting point for troubleshooting.

   1. Start the engine.

   2. Operate the engine at high idle.

   3. Shift the transmission into SECOND GEAR in the FORWARD direction.

   4. Attempt to operate the machine.

      Expected Results

      • The engine speed decreases.

      Results

      • OK: Check the brake pressure first. If the brake pressure is low, then the brake does not release. Proceed to Step 3.

      • NOT OK: Check the pressure to the transmission modulating valve first. Proceed to Step 4.

Show/hide table

Personal injury can result if the machine moves while testing. If the machine begins to move during test, reduce the engine speed immediately and engage the parking brake.

3. Check the brake pressure.
   

   Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Steering Clutch and Brake Pressure - Test"

   Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Steering Clutch and Brake Pressure - Test"

   Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Steering Clutch and Brake Pressure - Test"

   Expected Results

   • The pressure is correct.

   Results

   • OK: If the symptom is not resolved, an engaged transmission clutch could be preventing the transmission from operating properly. Proceed to Step 5.

   • NOT OK: A brake that is engaged could be preventing the movement of the machine. Proceed to Step 4.

4. Follow the procedure in this reference.

   Refer to "The Brake Does Not Release" in this module under Troubleshooting, "Brake Troubleshooting".

   Results

   • REPAIRED OK: Stop.

   • NOT OK: The cause of the problem is uncertain. Call technical support with the information that has been gathered.

5. Follow the procedure in this reference.

   Refer to "The Transmission Clutch Is Engaged and the Clutch Does Not Release" in this module under Troubleshooting, "Transmission Clutch Troubleshooting".

   Results

   • REPAIRED OK: Calibrate the transmission modulating valves.

   Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Calibration"

   Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

   Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

   • NOT OK: The cause of the problem is uncertain. Call technical support with the information that has been gathered.

6. Interchange the modulating valves.

   1. Interchange the transmission modulating valve for the No. 4 clutch with the transmission modulating valve for the No. 5 clutch.

   2. Determine whether the problem follows the valve.

      Results

      • FOLLOWS VALVE: Proceed to Step 7.

      • DOES NOT FOLLOW: Perform the following tests for the No. 4 clutch. Proceed to Step 8.

7. Replace the modulating valve.

   1. Replace the suspect transmission modulating valve.

   2. Calibrate the transmission modulating valves.
      

      Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Calibration"

      Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

      Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

   3. Check the operation of the machine for the original problem.

      Expected Results

      • The original problem is resolved.

      Results

      • OK: Stop.

      • NOT OK: Perform the following tests for only the No. 4 clutch. Proceed to Step 9.

8. Restore the modulating valve.

   1. Restore the transmission modulating valves to the original locations.

   2. Operate the machine under normal conditions.

      Expected Results

      • The original problem is resolved.

      Results

      • OK: An obstruction in the control valve may have been displaced during the procedure. Change the oil. Change the oil filter elements and clean the screens. Calibrate the transmission modulating valves.

      Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Calibration"

      Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

      Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

      • NOT OK: Perform the following tests for only the No. 4 clutch. Proceed to Step 9.

9. Follow the procedure in this reference.

   Refer to "The Transmission Clutch Does Not Engage" in this module under Troubleshooting, "Transmission Clutch Troubleshooting".

   Results

   • REPAIRED OK: Calibrate the transmission modulating valves.

   Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Calibration"

   Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

   Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

   • NOT OK: The cause of the problem is uncertain. Call technical support with the information that has been gathered.

The Transmission Does Not Operate in THIRD GEAR FORWARD or REVERSE

1. Check lockout control.

   1. Check the gear lockout control in order to determine whether the gear is available. The CaterpillarElectronic Technician ET service tool is required.

      Expected Results

      • Maximum track speed for FORWARD and REVERSE is less than 2.5

      Results

      • YES: operate in third gear because third gear is locked out. Stop.

      • NO: Proceed to Step 3.

2. Use Cat ET to check for the following diagnostics codes:
   • 1403-5 Transmission Solenoid 3: Current Below Normal

   • 1403-6 Transmission Solenoid 3: Current Above Normal

   Note: If any diagnostic codes are present repair the cause of the diagnostic codes before proceeding.

   Refer to Troubleshooting, "Solenoid Valve - Test"

3. Operate the machine.

   The probable cause of the problem is the transmission or the brakes. The following steps help you determine a starting point for troubleshooting.

   1. Use CaterpillarElectronic Technician ET

   2. Start the engine.

   3. Operate the engine at high idle.

   4. Shift the transmission into THIRD GEAR FORWARD.

   5. Attempt to operate the machine.

      Expected Results

      • The engine speed decreases.

      Results

      • OK: Check the brake pressure first. If the brake pressure is low, then the brake does not release. Proceed to Step 4.

      • NOT OK: Check the pressure to the transmission modulating valve first. Proceed to Step 6.

4. Check the brake pressure.
   

   Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Steering Clutch and Brake Pressure - Test"

   Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Steering Clutch and Brake Pressure - Test"

   Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Steering Clutch and Brake Pressure - Test"

   Expected Results

   • The pressure is correct.

   Results

   • OK: If the symptom is not resolved, an engaged transmission clutch could be preventing the transmission from operating properly. Proceed to Step 6.

   • NOT OK: A brake that is engaged could be an interference in the movement of the machine. Proceed to Step 5.

Show/hide table

Personal injury can result if the machine moves while testing. If the machine begins to move during test, reduce the engine speed immediately and engage the parking brake.

5. Follow the procedure in this reference.

   Refer to "The Brake Does Not Release" in this module under Troubleshooting, "Brake Troubleshooting".

   Results

   • REPAIRED OK: Stop.

   • NOT OK: The cause of the problem is uncertain. Call technical support with the information that has been gathered.

6. Follow the procedure in this reference.

   Refer to "The Transmission Clutch Is Engaged and the Clutch Does Not Release" in this module under Troubleshooting, "Transmission Clutch Troubleshooting".

   Results

   • REPAIRED OK: Calibrate the transmission modulating valves.

   Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Calibration"

   Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

   Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

   • NOT OK: The cause of the problem is uncertain. Call technical support with the information that has been gathered.

7. Interchange the modulating valves.

   1. Interchange the transmission modulating valve for the No. 3 clutch with the transmission modulating valve for the No. 5 clutch.

   2. Determine whether the problem follows the valve.

      Results

      • FOLLOWS VALVE: Proceed to Step 8.

      • Does not follow: Perform the following tests for the No. 3 clutch. Proceed to Step 9.

8. Replace the modulating valve.

   1. Replace the suspect transmission modulating valve.

   2. Calibrate the transmission modulating valves.

      Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Calibration"

      Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

      Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

   3. Check the operation of the machine for the original problem.
      

      Expected Results

      • The original problem is resolved.

      Results

      • OK: Stop.

      • NOT OK: Perform the following tests for only the No. 3 clutch. Proceed to Step 10.

9. Restore the modulating valve.

   1. Restore the transmission modulating valves to the original locations.

   2. Operate the machine under normal conditions.

      Expected Results

      • The original problem is resolved.

      Results

      • OK: An obstruction in the valve may have been displaced during the procedure. Change the oil. Change the oil filter elements and clean the screens. Calibrate the transmission modulating valves.

      Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Calibration"

      Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

      Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

      • NOT OK: Perform the following tests for only the No. 3 clutch. Proceed to Step 10.

10. Follow the procedure in this reference.

    Refer to "The Transmission Clutch Does Not Engage" in this module under Troubleshooting, "Transmission Clutch Troubleshooting".

    Results

    • REPAIRED OK: Calibrate the transmission modulating valves.

    Reference(PL72 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4132, "Calibration"

    Reference(PL83 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

    Reference(PL87 LRC and HRC) Specifications, Systems Operation and Testing and Adjusting, UENR4141, "Calibration"

    • NOT OK: The cause of the problem is uncertain. Call technical support with the information that has been gathered.