freightliner 108SD, Driver Manual

Page: 102 / 192

•
Never move the range-preselection lever with
the shift knob in neutral while the vehicle is
moving.
•
Skip ratios while shifting only when operating
conditions permit, depending on the load,
grade, and road speed.
•
Never coast with the shift knob in the neutral
position.
Upshifting
1. Position the gear shift knob 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, in
low range. See
Fig. 13.2 .
3. To start the vehicle moving, press the clutch
pedal to the floor; shift into 1st gear (
Table 13.1 ),
then engage the clutch with the engine at or near
idle speed. Accelerate to 80 percent of engine
governed speed.
Eaton Fuller Shift Progressions
TRANS. MODEL LOW RANGE HIGH RANGE
10-Speed Direct
or Overdrive (RT
or RTX)
2
3
4
1
f260329
R
5
9
8 10
7
f260330
R
6
Table 13.1, Eaton Fuller Range-Shift Shift
Progressions
4.
Upshift progressively from 1st gear through 5th
gear (
Table 13.1 ), double-clutching between
shifts, and accelerating to 80 percent of engine
governed speed.
5.
When in 5th gear and ready to move to 6th gear,
pull the range-preselection lever up into the high
range. Double-clutch through neutral and into 6th
gear, engage the clutch, and accelerate the en-
gine.
NOTE: If after attempting to shift into the high
range the transmission remains in neutral with
the shift knob in gear, the range synchronizer
protection device may be activated. Move the
shift knob into neutral to allow the range shift to
complete, then move the shift knob back into
gear.
6.
Upshift progressively through the high range
gears (
Table 13.1 ), double-clutching between
shifts and accelerating to 80 percent of engine
governed speed.
Downshifting
IMPORTANT: Never use the clutch brake when
downshifting, or as a brake to slow the vehicle.
1. Downshift progressively through each of the high
range gears, double-clutching between shifts.
2. When in 5th gear and ready to move to 4th gear,
push the range-preselection lever down into the
low range. Double-clutch through neutral and into
4th gear, engage the clutch, and accelerate the
engine.
NOTE: If after attempting to shift into the high
range the transmission remains in neutral with
the shift knob in gear, the range synchronizer
protection device may be activated. Move the
shift knob into neutral to allow the range shift to
complete, then move the shift knob back into
gear.
3. Downshift progressively through the low range
gears, double-clutching between shifts, as condi-
tions require.
Clutch
Clutch General Information
To ensure long service life of the clutch, start in the
right gear, be alert to clutch malfunctions, and know
when to adjust the clutch.
Typical operation will not break down the clutch fric-
tion surfaces. Heat and wear are almost nonexistent
when a clutch is fully engaged. However, during the
moment of engagement, when the clutch is picking
up the load, considerable heat is generated. If a
clutch slips excessively, high temperatures develop
quickly between the flywheel, driven discs, and pres-
sure plates. An improperly adjusted or slipping clutch
can generate temperatures high enough to cause the
friction-facing material to char and burn, destroying
the clutch.
Manual Transmissions and Clutch
13.5