TM 9-2320-263-10
c. Hauling Uphill:
The engine works hardest when moving a loaded truck up a grade. Proper use
of gear ranges will shorten the time on hills.
Unless the hill is extreme, begin in gear range 1-5, and depress the accelerator
pedal all the way downward. Keep it there as the truck moves up the grade.
If there is enough power to maintain a satisfactory road speed, remain in this
gear range and allow the transmission to upshift automatically.
If the hill causes a steady decrease in speed and engine rpm approaches 1,700,
manually downshift the range selector lever to the next lower range (1-4). Con-
tinue to downshift in this manner (1-3, 1-2, 1) to match the power demands of
the grade. Once the hill has been topped, return the gear range selector to the
1-5 position.
For starting on maximum grades with maximum load, start in gear range 1, depress
accelerator pedal to floor, and manually upshift the lever one range at a time,
shifting when engine speed approaches 2,000 rpm.
d. Using the Engine as a Braking Force:
Your truck is equipped with an engine retarder system which enables the engine
to act as a brake. The engine retarder should be used for descending grades,
in-city traffic or in any situation where slowing is required but excessive use of
the service brakes is not desirable. An example of this is wet or icy pavement.
The following procedures should be applied when appropriate:
1. Preset the ENGINE RETARDER switch on the instrument panel for the amount
of engine retarding you expect to need. Then all you have to do to obtain
the degree of engine retarding you need is remove your foot completely from
the accelerator pedal and press the engine retarder foot switch pedal.
2. Keep the truck in a gear range that gives you the rated rpm. The engine retarder
provides the most braking this way.
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