Engine Temperature; Clutch (If Equipped) - Mack Granite GU Series Operator's Handbook Manual

186 OPERATION
CAUTION
Running the engine at a speed that is too low for the load (or grade of the road) can
cause damage to the drivetrain.
Shifting at the proper time will result in increased fuel efficiency, as well as a
decrease in costly repairs. Remember that once the engine falls below peak
torque, both torque and horsepower will drop off very rapidly. Before this
happens, downshift to the next lower gear.
For vehicles with transmissions that have extreme reduction gearing coupled
with high rear-axle loads, a torque-limiting device should be used. This device
limits the amount of fuel that can be delivered to the engine and prevents
overloading of drivetrain components while in extreme reduction gears.
Always use the same gear going downhill as uphill. This will reduce brake
wear and prevent damage to the engine from overspeeding.

Engine Temperature

Before entering high-speed traffic conditions, allow the engine to reach normal
operating temperature. A normal operating range is between 77°C and 104°C
(170°F and 220°F) for stationary vehicles.

Clutch (If Equipped)

To avoid shock damage, release the clutch pedal smoothly, without
shock-loading the driveline (especially on grades while carrying heavy loads).
Do not ride the clutch pedal. Premature wear of the clutch facing and release
bearing may result.
CAUTION
Always use the lowest drive gear combination to start the vehicle moving to avoid
premature clutch failure.
1. To move the vehicle, start the engine and wait until it reaches operating
temperature.
2. Disengage the clutch by pushing the pedal to the floor.