The transmission system must be calibrated if any of the following conditions have occurred:
- A clutch solenoid modulating valve has been replaced or cleaned.
- A different power train ECM has been installed.
- A transmission clutch has been rebuilt.
- Harsh shifting exists.
Reference: For additional information on the clutch solenoid modulating valves, refer to the Service Manual module Systems Operation, "Modulating Valve (Transmission Clutch)" for the machine that is being serviced.
Calibration Procedure for Transmission Clutch Engagement
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. |
Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the attachments have been lowered, oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand. |
Escaping fluid under pressure, even a pinhole size leak, can penetrate body tissue, causing serious injury, and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury. Always use a board or cardboard when checking for a leak. |
NOTICE |
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Do not connect or disconnect hose fittings to or from the quick disconnect nipples when there is pressure in the system. This will prevent damage to the seals that are in the fitting. |
NOTICE |
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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. |
- Park the machine on a smooth, level surface.
- Shift the transmission direction switch to the NEUTRAL position. Shift the transmission speed switch to any speed position.
- Lower the blade or 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.
- Shut off the engine.
- 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 Required Tools     Part Number     Description     Quantity     1U-5481 (1)     Pressure Gauge Group     1     1U-5482     Hoses From the Pressure Adapter Group     1     139-4166     Data Link Cable     1     7X-1425     Cable     1     4C-6805     Adapter     1     171-4400     Communication Adapter Tool     1     Show/hide table( 1 ) The 198-4240 Pressure Indicator Tool Gp is also available.
- To access the transmission control, tilt the cab forward. Install support bracket (1) .
Reference: For additional information on the installation of cab support bracket (1), refer to the Service Manual module Disassembly and Assembly, "Cab Raise" for the machine that is being serviced.
Illustration 1 | g00615171 |
(1) Cab support bracket (2) Transmission control cover (3) Sensor connection for the oil temperature |
- Disconnect temperature sensor (3) .
- Remove control cover (2) .
- Label both ends of the six hoses that are from 1U-5482 Pressure Adapter Group (10). Install each hose assembly from 1U-5482 Pressure Adapter Group onto the pressure tap of the clutch solenoid modulating valve that is being calibrated.
Illustration 2 | g00606938 |
Transmission Clutch Solenoid Modulating Valves (4) Number 6 clutch solenoid modulating valve (First speed) (5) Number 5 clutch solenoid modulating valve (Second speed) (6) Number 3 clutch solenoid modulating valve (Fourth speed) (7) Six pressure taps for the clutch solenoid modulating valves (8) Number 1 clutch solenoid modulating valve (Reverse) (9) Number 2 clutch solenoid modulating valve (Forward) (10) Number 4 clutch solenoid modulating valve (Third speed) |
Illustration 3 | g00615243 |
Transmission Control (11) Labels on the hoses from the 1U-5482 Pressure Adapter Group . |
- Position clean cardboard (12) over the control valve. This will prevent excess oil from splashing out of the control. The cardboard will also help to block contaminants.
Illustration 4 | g00615293 |
- Connect oil temperature sensor (3) .
- Attach the opposite end of the hose assembly to the 0 to 3400 kPa (0 to 580 psi) pressure gauge in the 1U-5481 Pressure Gauge Group .
Illustration 5 | g00615380 |
- Make sure that transmission direction switch (15) is in the NEUTRAL position.
Illustration 6 | g00612687 |
Command Control Steering (14) Upshift/downshift switch. (15) Transmission direction selector. |
Illustration 7 | g00616160 |
STIC Steering Control (14) Upshift/downshift switch. (15) Transmission direction selector. |
- Make sure that the parking brake is engaged.
- Start the engine.
- Warm the transmission oil to approximately 40 °C (104 °F).
Note: The transmission oil temperature gauge should be at the center position.
- Start the engine and operate the engine at low idle.
Note: If a new clutch solenoid modulating valve was installed, shift the transmission for at least 12 times into a speed or a direction that uses the clutch solenoid modulating valve. Refer to Illustration 2 in order to identify the clutch solenoid modulating valve and the corresponding clutch. Allow sufficient time for the corresponding clutch to be fully pressurized.
- Increase the engine speed to high idle.
Note: You can use the SET/DECEL switch to maintain the high idle. The RESUME/ACCEL switch can be used to resume high idle.
Show/hide tableTable 2 Pressure Specification for Transmission Clutch Engagement     Model     Clutch 1     Clutch 2     Clutch 3     Clutch 4     Clutch 5     Clutch 6     834G    
2210 ± 70 kPa (320 ± 10 psi)    
2210 ± 70 kPa (320 ± 10 psi)    
2275 ± 70 kPa (330 ± 10 psi)    
2275 ± 70 kPa (330 ± 10 psi)    
1725 ± 70 kPa (250 ± 10 psi)    
2275 ± 70 kPa (330 ± 10 psi)    836G    
2210 ± 70 kPa (320 ± 10 psi)    
2210 ± 70 kPa (320 ± 10 psi)           
1725 ± 70 kPa (250 ± 10 psi)    
2275 ± 70 kPa (330 ± 10 psi)    Note: The software program that will be used for this test procedure is the Caterpillar Electronic Technician (ET). The Caterpillar Electronic Technician is a software program that can be used on an IBM-compatible personal computer.
Reference: For more information about the use of Electronic Technician, refer to Testing and Adjusting, "Using Caterpillar Electronic Technician (ET) to Determine Diagnostic Codes" for the machine that is being serviced.
- Open the software program (ET). Select the "Transmission 834G" or "Transmission 836G" menu item.
- Select the "Service" menu in order to begin the calibration procedure. Then select "Calibrations". A second menu will be displayed. Select "Transmission Clutch Engagement Pressure Calibrations" from the second menu.
- Once "Transmission Clutch Engagement Pressure Calibrations" has been selected, the screen displays a dialog box in order to select the clutch or the clutches for calibration. Initially, all of the clutches are selected. Individual clutches can be removed from the calibration procedure. Once the clutches for calibration are selected press the "Begin" button.
- The next screen is the initial calibration screen. The calibration screen displays the incremental instructions for calibration. The top display area displays status parameters that are monitored during the calibration. The middle display area displays information about the status of the calibration. The bottom display area displays incremental instructions for the calibration. The step that currently needs to be carried out is in bold text. All other steps are displayed in gray text.
- Press the "Next>" button in order to start the calibration. The "Next>" button is disabled, until the current step has been successfully completed. A check will be placed in the box that is left of the step, after the current step is complete. After the successful completion of a step, press the "Next>" button in order to begin the following step. Continue this process in order to complete the calibration procedure.
- Once the calibration for the clutch pressure begins, refer to Table 2 for the individual clutch pressures. The pressure for the clutch should match the pressure in Table 2. If the pressure does not match Table 2, adjust the pressure. Press buttons "<<", "<", ">", or ">>" at the bottom of the screen in order to adjust the flow of current to that clutch solenoid. When the desired pressure is reached press the "Next>" button in order to continue the calibration.
- A dialog box will appear after the calibration of each clutch is complete. The dialog box displays the selected calibrations and the status. After viewing the status, select the "Continue" button or the "Cancel" button. If you press the "Continue" button, the Electronic Technician will display the instructions for the calibration of the next clutch. The entire calibration procedure will end If the "Cancel" button is pressed.
- To exit the calibration, select the "File" menu and then select "Exit".