clutch pedal with your left foot. To shift gears smoothly
and quietly, you must keep the pedal fully depressed
until the shift has been completed.
You should understand that the clutch provides the
means of applying engine power to the wheels smoothly
and gradually. To be a professional operator, you must
learn just where the clutch starts to engage, how far the
pedal must move to become fully engaged how much
free play there is in the pedal, and how fast you should
engage the clutch.
Keep your foot off the clutch pedal except when
actually starting, stopping, or shifting gears. Even the
slight constant pressure on the clutch pedal causes
excessive wear. For the same reason, when stopped on
a hill, never slip your clutch to keep from rolling
backward; instead, use the brakes. Depress the clutch
pedal and shift the transmission shift lever into neutral
while waiting for a long traffic light or when halted for
other reasons. Release the clutch after shifting into
When slowing your vehicle to stop or make a turn,
be sure to reduce the vehicle speed to 15 miles per hour
or less before depressing the clutch pedal. Coasting a
vehicle at a high rate of speed with the clutch pedal
depressed is dangerous, because control becomes more
difficult and damage to the clutch may occur. This kind
of practice is abusive to the vehicle.
CLUTCH SHIFTING. After the prestart
operation has been performed and you have acquainted
yourself with the instruments and controls of the
vehicle, warm the engine with the transmission in
neutral. Start the vehicle moving with the transmission
in low or first gear by following these steps:
1. Depress the clutch pedal and shift into low gear.
2. Check the mirrors, check blind spots, and give
signals as required.
3. Let the clutch pedal up slowly, pausing at the
friction point or when you feel it taking hold. Again,
recheck the mirrors for traffic.
4. Release the parking brake and slowly release the
clutch pedal, and at the same time, slightly depress the
5. When the driving operation is under way,
remove your left foot completely from the clutch pedal.
DOUBLE-CLUTCH SHIFTING. Professional
driving practice in trucks (1 1/2 ton or larger) often
requires double clutching to permit proper engagement
of the gears and to prevent loss of momentum. To shift
to a lower gear by double clutching, follow these steps:
1. Release the pressure from the accelerator as you
begin depressing the clutch pedal.
2. When the clutch pedal is fully depressed, move
the gearshift lever to neutral position
3. Release the clutch pedal, and at the same time,
depress the accelerator to speed up the engine.
4. Letup on the accelerator and depress the clutch
5. While the pedal is depressed move the gearshift
lever to the next lower gear.
6. Release the clutch pedal, and at the same time,
depress the accelerator to maintain engine speed as the
load is again connected to the engine by the engagement
of the clutch.
The procedure is the same for shifting to a higher
gear speed, except that the engine is NOT accelerated
while the transmission is in neutral.
When you are shifting gears in rough
terrain and on hills, never let your vehicle slow
down to a point where the engine begins to labor
or jerk before shifting into a lower gear ratio.
Always anticipate the need for extra power and
shift gears accordingly. When descending a
hill, with or without a heavy cargo load, always
drive with your vehicle in gear and the clutch
NOTE: You may encounter vehicles that may have
more complicated transmissions, such as multigear
ranges, dual-speed axles, or other special features. As
an operator, read and understand the operators manual
pertaining to a particular vehicle before attempting to
The automatic transmission, like the manual
transmission, is designed to match the load requirements
of the vehicle to the power and speed range of the
engine. However, the automatic transmission (fig. 2-6)
performs this automatically, depending on the throttle
position, vehicle Speed, and position of the shift control
lever. Automatic transmissions are manufactured in
models that have two, three, four, or more forward