SPRING 3135833 - Caterpillar

Machine Preparation
Park the machine on a smooth, level surface.
Shift the transmission direction control switch to the NEUTRAL position.
Lower the bucket or the work tool to the ground.
Engage the parking brake.
Place blocks in front of the wheels and behind the wheels.
Allow only authorized personnel on the machine. Keep unauthorized personnel off the machine and in clear sight of the operator.
Shut off the engine.Note: This calibration procedure can be performed without a running engine.
Turn the key start switch and the disconnect switch to the ON position.Note: This calibration can only be performed with Caterpillar Electronic Technician. Power to the ECM must be cycled in order for the calibration to take effect.Procedure for Adjusting the Maximum Reverse Gear in Electronic Technician
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.
Table 1
Required Tools    
Part Number     Description     Quantity    
139-4166     Data Link Cable     1    
7X-1425     Cable     1    
4C-6805     Adapter     1    
171-4400     Communication Adapter Tool     1    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.
Illustration 1 g01107098
Service connector for the Caterpillar Electronic Technician
Connect the laptop computer to the service connector in the cab. The service connector is located to the left of the key start switch.
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Open the software program (ET). Select "Transmission" from the "ECM Selector" menu.
Illustration 3 g01183355
Select the "Service" menu item from the toolbar. Select the "Configuration" menu item.
Illustration 4 g01183466
Highlight the option for the "Transmission Maximum Reverse Gear" on the configuration screen. Click on the "Change" button in the bottom left of the screen. Enter the new value for the maximum reverse gear. See Table 2 for a list of the available gears. Click the "OK" button.
Table 2
Machine     Maximum Reverse Gear     Minimum Reverse Gear    
966 and 972     4     2    
Illustration 5 g01111261
Click the "Yes" button.
The value of the maximum reverse gear has been changed.
Close the software program (ET). Shut down the laptop computer. Disconnect the computer from the service connector in the cab.