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Operating Instructions Operating the Transmission
Medium Duty
(R10/06) Y53-6008 – 69 –
If you have a misaligned gear condition in your vehicle's
transmission and cannot start, gradually release the clutch,
allowing the drive gear teeth to line up properly. Then the
drive gear can roll enough to allow the teeth to line up prop-
erly and complete the shift.
The best engine performance and maximum economy is
obtained if gears are properly selected. This efficiency is
achieved by always selecting gears within optimum engine
rpm, which is where maximum torque and power are
obtained. For further information, see “
More Driving Tips and
Techniques” on page 98.
Shifting Gears in a New Vehicle
Shift carefully in a new vehicle. The transmission may be a lit-
tle stiff at first. Avoid gear clashing by closely following these
procedures.
When you are operating a new vehicle or one that has been
exposed to cold weather, you want the transmission lubricant
(fluid) to circulate and coat the contacting surfaces of the
gears. Metal contacting metal in moving parts may seriously
damage your transmission—do not drive in one gear for long
periods of time until the transmission lubricant has a chance
to coat all contacting surfaces. Carefully observe the free
travel in the clutch for the first few hundred miles. As the
clutch lining wears and high spots get worn smooth, you will
get less free travel.
Clutch Brake and Travel (9–, 10–, and 11–Speed
Transmissions only)
These transmissions utilize a clutch brake, rather than syn-
chronizers. The clutch brake works by stopping all of the
gears in the transmission, allowing you to easily shift into first
gear or reverse without grinding gears. The total stroke of the
clutch pedal is about 10 inches. The first part is the release
stroke: the part that fully releases the clutch. The last inch
engages the clutch brake.
During hard-shifting with vehicle not moving
To apply the clutch brake (while the vehicle is stopped)
fully depress the clutch pedal to the floorboard to stop
the gears. With the throttle at idle, select first gear then
release the clutch pedal to let the vehicle start forward,
until the clutch is fully engaged. See the transmission
manufacturer's manual that is included with your vehicle
for further details.