D3C Series III, D4C Series III and D5C Series III Hystat Track-Type Tractors Power Train Caterpillar

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Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine. To prevent possible injury, perform the procedure that follows before testing and adjusting the power train.

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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.

If the machine cannot be placed on stands for testing, an area of level ground may be used. The machine may be tested in the following manner.

1. Typically, 100 m (328 ft) is required to allow a machine to be tested for tracking at maximum speed.

   Note: Only one person should be on the machine during this test.

2. Perform the following procedure in order to determine if the motor is destroking in FAST speed.

   1. Operate the machine at maximum speed in the SLOW speed.

   2. Move the speed control switch to the FAST position.

      If the machine speeds up then the motor has destroked. However, the accurate tests must be run with gauges. Refer to the testing procedures in Testing and Adjusting, "Control Test (Pump and Motor)". This procedure ensures one that the motor is set to the correct specifications.

3. Place a durable mark on the bottom of the track near the top of the track roller.

4. Start the engine and disengage the parking brake. Place the throttle at high idle.

5. Place the speed selector switch in the FAST mode. Move the speed/direction control lever into the FORWARD position.

6. After moving approximately 100 m (328 ft), move the speed/direction control lever into the NEUTRAL position. Return the throttle to low idle. Engage the parking brake. Stop the engine. The machine should not track more than 6 m (20 ft) to one side.

7. Walk to the left side of the machine. Observe the location of the mark on the track. Walk to the right side of the machine. Observe the location of that mark. If the marks are not within 1.5 m (5 ft) adjust the pump or adjust the motor.

8. Refer to the tests in Testing and Adjusting for additional information.