Chevrolet Silverado 4500HD/5500HD/6500HD Owner Manual (GMNA-
Localizing-U.S.-12102101) - 2019 - crc - 10/2/18
228
Driving and Operating
On vehicles with a diesel engine,
Tow/Haul Mode Grade Braking can
be enabled or disabled by pressing
the Tow/Haul Mode button. Use the
exhaust brake and Tow/Haul Mode
for maximum grade braking.
See
For other forms of grade braking,
see
.
Drive Systems
Four-Wheel Drive
If equipped with four-wheel drive,
the engine's driving power can be
sent to all four wheels for extra
traction.
Caution
Do not drive on clean, dry
pavement in 4
m
and 4
n
(if
equipped) for an extended period
of time. These conditions may
cause premature wear on the
vehicle
’
s powertrain.
Driving on clean, dry pavement in
4
m
or 4
n
may:
.
Cause a vibration to be felt in
the steering system.
.
Cause tires to wear faster.
.
Make the transfer case harder to
shift, and cause it to run noisier.
Caution
Extended high-speed operation in
4
n
may damage or shorten the
life of the drivetrain.
Engagement noise and bump when
shifting between 4
n
and 4
m
, with
the engine running, is normal.
Manual Locking Hubs
{
Warning
It is dangerous to get out of the
vehicle if the shift lever is not fully
in P (Park) with the parking brake
firmly set. The vehicle can roll.
Do not leave the vehicle when the
engine is running. If you have left
the engine running, the vehicle
can move suddenly. You or others
could be injured. To be sure the
vehicle will not move, even when
you are on fairly level ground,
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