Peterbilt 579 - Putting the Vehicle in Motion

OPERATING THE TRANSMISSION
Putting the
Vehicle in Motion
After making sure the vehicle's oil
Always use
rst gear or a low speed
and air pressure are correct and all
range to
start the vehicle in motion.
other parts and systems are in proper
The use
of a higher gear or speed
working condition:
range forces undue strain on the en-
gine, clutch, other transmission com-
manual transmission) until the
1. Fully depress the clutch pedal (for
ponents, and
may cause damage.
clutch brake makes contact.
2. Evaluate the road surface
CAUTION
a. The total stroke of the clutch
conditions and
terrain your vehicle
pedal is
about 6 inches (152
is on.
Select a gear low enough to
mm). The
rst ½ inch (13
let your
vehicle start forward with
mm) is
free travel. After the
the throttle
at idle.
free travel
comes the release
stroke, which is the part that
3. Push the parking brake valve
fully releases the clutch. The
handle (Yellow) against the dash
last ½ inch (13 mm) engages
panel to release the brakes.
the clutch
brake.
4. Release
the clutch pedal (manual
b. Always start
out in a low
only), then gradually accelerate to
gear.
Starting in higher gears,
permit smooth starting,
even with a light load, will
5. Do
not allow your vehicle
cause a
very jumpy start and
to roll
(even a little) in the
excessive wear.
opposite direction
during clutch
engagement. If you need to
start up
on an incline, apply your
service brakes before you release
the parking brake. Then release
your service brakes as you engage
the clutch and apply throttle.
For further
instructions on
operating your transmission, see
the transmission manufacturer's
Driver/Operator's Instruction Manual.
If you
have a misaligned gear condition
in your vehicle's transmission and
cannot start, gradually release the
clutch, allowing the drive gear teeth to
line up properly. Then the drive gear
can roll enough to allow the teeth to
line up properly and complete the shift.
The best
engine performance and
maximum economy is obtained if gears
are properly selected. This efciency
is achieved by always selecting gears
within optimum engine RPM, which is
where maximum torque and power are
obtained. For further information, see
4
(04/13) Y53-6047–2C 4-15