D3K2, D4K2 and D5K2 Track-Type Tractor Systems Caterpillar

Specifications

Introductions

The important part of this data is understanding that the pumps are upstroking toward maximum displacement while the speed rises from zero to approximately 1.5. The motors remain at maximum displacement during this period. From approximately 1.5 to 3, the motors are destroking from maximum displacement to minimum displacement. There is some overlap between these two regions around 1.5. From 0 to 1.5, you should see increases only in the following:

• "Pump Current"

• "Desired Gear Ratio"

• "Motor Speed"

From 1.5 to 3, the "Pump Current" should be constant. You should see increases only in the following:

• "Motor Current"

• "Desired Gear Ratio"

• "Motor Speed"

At all times, the left values and the right values should be equal. Look for significant differences between left values and right values. Check the speed when these differences appear.

Note: The following is an example of using this data: The current for the left motor and the current for the right motor increase together as the speed setting is increased. The right motor speed stops increasing at 2.5, while the current for the right motor continues to increase. This difference might indicate that the displacement control spool in the right motor is sticking.

The above example is only one possible scenario. Contact Small Track-Type Tractor Product Support for help with the final diagnosis of the problem.

Required Tools

Illustration 1	g02581096
Tooling (B) 317-7484 Communication Adapter III

Test Preparation - Speed Sweep

1. Move the machine to a smooth horizontal location.

2. Permit only one operator on the machine. Keep all other personnel away from the machine or in the operator sight.

3. Place the machine on jack stands.

4. Place the steering control lever in the NEUTRAL position.

5. Engage the parking brake.

6. Lower the attachments to the ground.

7. Stop the engine.

Test Procedure - Speed Sweep

Illustration 2	g02560258

The Speed Sweep Test is performed manually. You will need ET in order to collect the required data. Create a group in ET that allows you to monitor the following parameters:

• "Left Forward Pump Solenoid Current"

• "Right Forward Pump Solenoid Current"

• "Left Motor Solenoid Current"

• "Right Motor Solenoid Current"

• "Left Motor Speed"

• "Right Motor Speed"

• "Left Desired Gear Ratio"

• "Right Desired Gear Ratio"

1. Perform the steps in the "Test Preparation - Speed Sweep" then continue the following steps.

2. Enter the machine.

3. Fasten the seat belt.

4. Start the engine.

5. Increase engine speed to 2100 rpm (HIGH IDLE).

6. Release the parking brake.

7. Move the speed and direction control to the FORWARD position.

8. Use the thumb wheel on the speed and direction control to set the speed range to "1" on the display.

9. Record the desired values for this speed range onto the speed sweep values table1. Refer to "Specifications".

10. Use the thumb wheel to set the speed range to "1.5" on the display.

11. Record the desired values for this speed range onto the speed sweep values table1. Refer to "Specifications".

12. Use the thumb wheel to set the speed range to "2" on the display.

13. Record the desired values for this speed range onto the speed sweep values table1. Refer to "Specifications".

14. Use the thumb wheel to set the speed range to "2.5" on the display.

15. Record the desired values for this speed range onto the speed sweep values table1. Refer to "Specifications".

16. Use the thumb wheel to set the speed range to "3" on the display.

17. Record the desired values for this speed range onto the speed sweep values table1. Refer to "Specifications".