POWER TRAIN
The power train furnished on 6x4 carriers (units
having two driving axles at rear) includes the engine,
clutch, transmission, rear tandem axles and the
necessary propeller shafts to transfer torque (power)
between these units.
The major variations found on 6x6 carriers (units
having two driving axles at rear and a third driving
axle in front) are the substitution of a front driving
axle in place of a non-driving front axle and the
addition of a transfer case to drive front axle.
Clutch
The clutch is located within a housing between the
engine and transmission and functions to control
the transfer of torque from engine to transmission.
Depressing the clutch pedal disengages the clutch
and prevents a transfer of torque from the engine to
the transmission. Releasing the clutch pedal engages
the clutch and causes a transfer of torque from the
engine to the transmission.
Countershaft Brake
The countershaft brake slows rotation of transmission
gearing. Its
only
purpose is to ease the shift from
neutral to LO LO, LO, 1st or reverse gear
while the
carrier is stopped.
The countershaft brake is controlled by the counter-
shaft brake button (mounted on front side of shift
lever). Depress button to apply brake and release
button to release brake.
Do not
use countershaft brake when downshifting.
Transfer Case
(for 6x6 units only)
The transfer case is a gearbox located between the
transmission and rear tandem axles. It functions with
the transmission to transmit torque to the front and rear
driving axles.
Front axle drive is controlled by the front wheel drive
toggle located on the dashboard.
2 2
Do not engage front axle drive while carrier
is moving. Stop carrier before shifting.
Transmission
The transrnission is a gearbox which transmits torque
from the engine as it is delivered to move the carrier.
The transmission in your carrier provides 8 forward
speeds plus Lo Lo and Lo. It also provides 3 corre-
sponding reverse gear ranges.
The lowest transmission gear (LO LO) provides the
greatest carrier torque and the lowest carrier speed. The
highest transmission gear (8th gear) provides the
greatest carrier speed with the least carrier torque. Gear
selections between these gear ranges provide torque/
speed combinations between these extremes. Reverse
gears provide approximately the same torque/speed
ratios as LO LO, LO and 1st gears.
Although your transmission is classified as having
eight forward speeds, LO LO and LO can be included
in the sequence of upshifting and downshifting. This,
in effect, provides ten torque/speed ranges if required
by conditions. However, it should seldom be neces-
sary to use LO LO except under severe conditions. In
most on-highway conditions the Lo plus the numbered
gears will provide adequate torque for travel.
