The service brakes must be applied when the tests are performed. Make sure that the service brakes are fully operational before you perform any tests.
Make sure that the transmission oil is at the normal operating temperature of 80° to 105°C (121° to 176°F) when any tests are performed.
The drive wheels must not turn during this double stall test. Position the machine against a solid, stationary object such as a loading dock.
 |
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. To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before operating the machine. |
 |
- Start the engine.
- Apply the service brakes.
- Disengage the parking brake. Shift the transmission direction and speed control to THIRD SPEED FORWARD and fully depress the accelerator pedal.
| NOTICE |
|---|
To ensure that the transmission oil does not overheat, do not keep the torque converter in a full stall condition for more than 30 seconds. After the torque converter stall test, reduce the engine speed to low idle. In order to cool the oil, move the transmission control to the NEUTRAL position and run the engine between 1200 rpm and 1500 rpm. |
- Allow the engine rpm to stabilize. Then, observe the tachometer. The correct torque converter stall speed should be 1910 ± 100 rpm.
 | |
| Illustration 1 | g00742649 |
(1) Speedometer/Tachometer module (2) Display for the monitoring system (3) Gauge display | |
- Reduce the engine speed to low idle. Shift the transmission direction and speed control to the NEUTRAL position.
Allow the engine coolant and the transmission oil to cool. Wait for at least two minutes between tests in order to allow the transmission oil to cool.
If the torque converter stall speed is more than 2010 rpm, the engine power output could be too high or the torque converter could have excess slippage.
If the torque converter stall speed is less than 1810 rpm, the engine may not be developing full power. There may be a parasitic load on the engine.
Reference: For additional information about the Caterpillar Monitoring System, refer to the Service Manual module Systems Operation, "Caterpillar Monitoring System" for the machine that is being serviced.
Reference: For additional information about troubleshooting the transmission and the torque converter, refer to the Service Manual module Testing and Adjusting, "Power Train Troubleshooting" for the machine that is being serviced.