Navistar WorkStar Series, Operator'S Manual

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Operation
Two-Position Regeneration Inhibit Switch
With the optional two-position switch, pressing the ON position
of the ON/INHIBT REGEN switch will inhibit both normal and
parked regeneration. Regeneration will be inhibited (latched)
when in this position and the switch indicator is turned on.
Three-Position Regeneration Inhibit Switch
The optional three-position switch is a center stable momentary
switch. Pressing the ON position inhibits normal regeneration
while the engine is running and is reset when the ignition switch
is turned off. The Inhibit function is cancelled when the lower
position is pressed, or parked regeneration is initiated (PARKD
REGEN switch is turned to the ON position).
The switch indicator will be turned on whenever regeneration
inhibit is enabled.
Transmission
Manual Transmissions
Vehicles with manual transmissions have a clutch pedal that is
used to engage or disengage the clutch or for connecting or
disconnecting the engine from the transmission and rear wheels.
With the clutch pedal released (extended), the clutch is engaged,
driving the transmission and rear wheels. Depressing the clutch
pedal releases the clutch, permitting transmission gear changes.
Clutches will last many thousands of miles if properly used and
maintained. EXCESS HEAT IS A CLUTCH’S WORST ENEMY!
Almost every early clutch failure can be traced to excessive
friction heat. Do not ride or slip the clutch. Once a clutch is
fully engaged, there is no heat generated and little or no wear.
However, during the brief period when the clutch is picking up
the load, considerable heat is generated. By riding or slipping
the clutch, the period of partial engagement is lengthened,
causing unnecessary heat and wear.
Engaging the Clutch
Always start in the proper gear: An empty vehicle can be
started in a higher gear than a fully loaded one. But starting in a
gear too high for the load can cause too much clutch slippage,
generating excessive heat and unnecessary wear. A gear that
will start the vehicle moving with the engine at idle speed is
usually correct.
If the engine must be revved up to prevent
stalling, the gear selection is too high. As the clutch pedal is
released and the clutch begins to engage, the engine speed will
drop slightly. When this happens, increase the engine speed
and fully engage the clutch. Increasing the engine speed before
fully engaging the clutch can damage the clutch and drive train.
Do not shift until vehicle has reached proper speed.
Upshifting before the vehicle has reached the right speed is
almost as bad as starting off in too high a gear.
When the
difference between the vehicle speed and the engine speed is
too great, the clutch is forced to slip. The result is extra heat
and wear.
Never hold a vehicle on a hill with the clutch. To hold on a hill
with the clutch requires that the clutch be purposely slipped. By
doing this, enough heat can be generated to burn up the clutch.
Never coast with the clutch disengaged. This can cause
clutch failure by the very high RPM encountered when coasting
in gear with the clutch released. In this situation, the rear wheels
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