Upshifting
1.
Position the gear shift lever in neutral. Start the
engine and bring the air system pressure up to
100 to 120 psi (689 to 827 kPa).
2.
Position the range preselection lever down into
low range.
3.
Press the clutch pedal to the floor. Shift into low
or first gear, then engage the clutch with the en-
gine at or near idle speed to start the vehicle
moving. Accelerate to 80 percent of engine gov-
erned speed.
4.
Shift progressively up from low or 1st gear to the
top gear in low range, double-clutching between
shifts and accelerating to 80 percent of engine
governed speed.
5.
While in the top gear of the low-range shift pat-
tern and ready for the next upshift, flip the range
preselection lever up into high range. Double-
clutch through neutral and shift into the bottom
gear in high range. As the shift lever passes
through neutral, the transmission will automati-
cally shift from low range to high range.
6.
With the transmission in high range, shift pro-
gressively up through each of the high range
gears, double-clutching between shifts.
Downshifting
1.
With the transmission in high range, shift pro-
gressively down to the bottom gear in high
range, double-clutching between shifts.
2.
When in the bottom gear of the high-range shift
pattern and ready for the next downshift, push
the range preselection lever down into low range.
Double-clutch through neutral and shift into the
top gear of the low-range shift pattern. As the
shift lever passes through neutral, the transmis-
sion will automatically shift from high range to
low range.
3.
With the transmission in low range, downshift
through the low range gears as conditions re-
quire.
Never use the clutch brake when downshifting or
as a brake to slow the vehicle.
Operation, Deep-Reduction Models
Upshifting
1.
Position the gear shift lever in neutral. See
for the shift pattern. Start the engine,
and bring the air system pressure up to 95 to
125 psi (655 to 862 kPa).
2.
Position the range preselection lever down, into
low range.
NOTE: If conditions are difficult, start out in LO-
LO. Move the DEEP REDUCTION lever on the
dashboard to the IN position. Otherwise start
out in LO with the DEEP REDUCTION lever in
the OUT position.
3.
Depress the clutch pedal to the floor. Shift into
LO gear; then, engage the clutch, with the en-
gine at or near idle rpm to start the vehicle mov-
ing. The vehicle will start in LO or LO-LO de-
pending on the DEEP REDUCTION lever
position.
4.
To upshift if in LO-LO, move the DEEP REDUC-
TION lever to the OUT position and
immediately
release the accelerator, depress the clutch pedal
once to break torque, and reengage the clutch.
The auxiliary section will shift from LO-LO to LO
when the gears reach the same speed.
5.
Shift progressively upward from LO through 1st,
2nd, 3rd, and 4th gears while the range prese-
lection lever is in LO. Always double-clutch be-
tween gears.
6.
When in 4th gear and ready for the next upshift,
pull up the range preselection lever and move
the shift lever, double-clutching, to the 5th gear
position. As the shift lever passes through neu-
tral, the auxiliary section will automatically shift
from low to high range.
NOTICE
Never move the shift lever into the LO gear posi-
tion after high range preselection or anytime the
auxiliary section is in high range. Transmission
damage could result.
7.
Continue upshifting from 5th gear through 8th
gear, always double-clutching between gears.
Downshifting
1.
While in high range, move the gear shift lever
from 8th gear through 5th gear as conditions re-
quire, always double-clutching between gears.
2.
When in 5th gear and ready for the next down-
shift, push down the range preselection lever and
move the shift lever to the 4th gear position,
being sure to double-clutch. As the shift lever
Drivetrain
8.11
