Putting The Vehicle In Motion - Peterbilt 348 2017 Operator's Manual

Putting the Vehicle in Motion

After making sure the vehicle's oil
and air pressure are correct and all
other parts and systems are in proper
working condition:
1. Fully depress the clutch pedal (for
manual transmission) until the
clutch brake makes contact.
a. The total stroke of the clutch
pedal is about 6 inches (152
mm). The first ½ inch (13
mm) is free travel. After the
free travel comes the release
stroke, which is the part that
fully releases the clutch. The
last ½ inch (13 mm) engages
the clutch brake.
b. Always start out in a low
gear. Starting in higher gears,
even with a light load, will
cause a very jumpy start and
excessive wear.
(03/17)
CAUTION
Always use first gear or a low speed
range to start the vehicle in motion.
The use of a higher gear or speed
range forces undue strain on the en-
gine, clutch, other transmission com-
ponents, and may cause damage.
2. Evaluate the road surface
conditions and terrain your vehicle
is on. Select a gear low enough to
let your vehicle start forward with
the throttle at idle.
3. Push the parking brake valve
handle (Yellow) against the dash
panel to release the brakes.
4. Release the clutch pedal (manual
only), then gradually accelerate to
permit smooth starting,
5. Do not allow your vehicle
to roll (even a little) in the
opposite direction during clutch
engagement. If you need to
Y53-6060-1C1
OPERATING THE TRANSMISSION
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 efficiency
is achieved by always selecting gears
within optimum engine RPM, which is
where maximum torque and power are
obtained. For further information, see
4
4-19