Usage:
Proper operation and maintenance are key factors in determining the useful life and economy of a truck engine. Follow the directions in this guide for trouble-free, economical truck engine operation.
After the engine starts, reduce engine RPM to low idle with no load.
(1674 and 1693: Before normal oil pressure is reached the governor control linkage travel is limited to below half engine speed by an oil pressure actuated stop inside the governor.) Do not attempt to force the governor control linkage past the stop. When normal oil pressure is reached, operate the engine at low load for 5 minutes before applying full load.
Select the lowest gear for a smooth, easy start without slipping the clutch. Rapid engine acceleration causes heavy exhaust smoke and high fuel consumption with no increase in vehicle performance. For best performance, do not skip gears when loaded.
Caterpillar engines have good lugging characteristics; however, avoid operating in a lug condition for extended periods of time as it causes exhaust temperatures to rise and results in high fuel consumption. A lug condition exists when an increase in engine speed cannot be achieved with an increase in accelerator pedal position, or when engine speed decreases with the accelerator pedal in its maximum position. A lug condition can exist at any engine speed below full load speed.
Continue to upshift until cruising speed is reached. Cruising speed should be between three-fourths and full governed RPM. (The governor will maintain a constant speed without accelerator pedal correction.)
On upgrade, begin downshifting if engine starts to labor. Downshift until a gear is reached in which the engine will pull the load without lugging. For best performance, downshift before engine RPM falls below peak torque RPM (see page 2).
On downgrade, do not coast or put transmission in neutral. Select the correct gear to keep engine speed below idle and retard the vehicle. A simple rule to follow is to select the same gear that would be used to go up the grade. Do not allow engine speed to exceed high idle.
Before stopping the engine, operate at low load for 5 minutes, then at low idle for 30 seconds. (This procedure allows hot areas in the engine to cool gradually, extending the engine life.) To stop the engine, use one of the methods listed.
TO STOP THE ENGINE, DO ONE OF THE FOLLOWING, DEPENDING ON TRUCK ARRANGEMENT
- 1. Turn the key to the spring-loaded position and hold until engine stops, then release key, or
- 2. Pull out the manual shutoff control, or
- 3. Push in and hold stop button until engine stops, then release button, or
- 4. Pull up on the accelerator.