Mack T318, T318L And T318Lr Shifting Instructions - Mack Granite GU Series Operator's Handbook Manual

222 OPERATION
MACK T318, T318L and T318LR Shifting
Instructions
CAUTION
Make sure air pressure is at least 90 psi and unit is at operating temperature before
making range shifts. Always start in LO range. This also applies to dynamometer
testing. When the truck is stationary, do NOT shift into HI range and then start
moving the truck. Otherwise, damage to the synchronizer may result.
Note: When making a SPLIT SHIFT from gear to gear, the splitter switch must not
be actuated, either up or down, until the main box is in NEUTRAL. When making
a SPLIT SHIFT in the same gear to a preselected gear, especially under a heavy
load, the splitter will not shift until the driveline torque is relieved. This can be done
by depressing the clutch pedal and releasing it, or by backing off the throttle and
reapplying it. The splitter switch must not be actuated, either up or down, until
IMMEDIATELY before the driveline torque is relieved. When making a RANGE
SHIFT, it is important to preselect the range shift. This means that the range selector
must be moved to its next position (up or down) BEFORE the gearshift lever is
moved. Then move the gearshift lever through NEUTRAL to the next desired gear
position. As the lever passes through NEUTRAL, the range shift will be completed.
Upshift — For purposes of explaining the shifting procedures through ALL
gears, assume that the vehicle has a full load and will climb a slight grade.
To prepare for moving the vehicle, position the shift lever in NEUTRAL, select
LO-split using the splitter switch, and select LO range using the range selector.
Refer to the shift pattern and move the shift lever to LO speed gear (LO
range, LO-split). Apply accelerator and engage the clutch, then accelerate
to governed speed. Select HI on the splitter switch (preselect) and release
the accelerator pedal long enough for the split shift to complete. Reapply the
accelerator. Shift through first LO-split, first HI-split, second LO-split, second
HI-split and so on, until you reach fourth HI-split. Remember to double-clutch
between gears.
To continue while in fourth gear HI-split, flip the range selector up to HI range
(preselect), and as you move the shift lever through NEUTRAL to fifth gear,
move the splitter switch from HI to LO. As the lever moves through NEUTRAL,
the range shift to HI will be completed. You are now in fifth gear LO-split (HI
range). Continue shifting to fifth HI-split, sixth LO-split, sixth HI-split and so
on, until you reach eighth HI-split. Remember to double-clutch between gears.