GMC SIERRA 2018 Owner's Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
370 Vehicle Care
Warning (Continued)
not careful. SeeJump Starting -
North America 0426 for tips on
working around a battery without
getting hurt.
Infrequent Usage: Remove the
black, negative (−) cable from the
battery to keep the battery from
running down.
Extended Storage: Remove the
black, negative (−) cable from the
battery or use a battery trickle
charger.
Four-Wheel Drive
Transfer Case
When to Check Lubricant
Refer to Maintenance Schedule
0 448 to determine when to check
the lubricant.
1. Fill Plug
2. Drain Plug
To get an accurate reading, the
vehicle should be on a level
surface.
If the level is below the bottom of
the fill plug (1) hole, located on the
transfer case, some lubricant will
need to be added. Add enough
lubricant to raise the level to the
bottom of the fill plug (1) hole. Use
care not to overtighten the plug. When to Change Lubricant
Refer to
Maintenance Schedule
0 448 to determine how often to
change the lubricant.
What to Use
Refer to Recommended Fluids and
Lubricants 0456 to determine what
kind of lubricant to use.
Front Axle
When to Check and Change
Lubricant
It is not necessary to regularly
check front axle fluid unless a leak
is suspected, or an unusual noise is
heard. A fluid loss could indicate a
problem. Have it inspected and
repaired.
How to Check Lubricant
To get an accurate reading, the
vehicle should be on a level
surface.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 371
1500 Series
1. Fill Plug
2. Drain Plug
All Except 1500 Series
1. Fill Plug
2. Drain Plug
.When the differential is cold, add
enough lubricant to raise the
level from 0 mm (0 in) to 3.2 mm
(1/8 in) below the fill
plug (1) hole.
. When the differential is at
operating temperature (warm),
add enough lubricant to raise the
level to the bottom of the fill
plug (1) hole. What to Use
Refer to
Recommended Fluids and
Lubricants 0456 to determine what
kind of lubricant to use.
Rear Axle
When to Check Lubricant
It is not necessary to regularly
check rear axle fluid unless a leak is
suspected or an unusual noise is
heard. A fluid loss could indicate a
problem. Have it inspected and
repaired.
All axle assemblies are filled by
volume of fluid during production.
They are not filled to reach a certain
level. When checking the fluid level
on any axle, variations in the
readings can be caused by factory
fill differences between the minimum
and the maximum fluid volume.
Also, if a vehicle has just been
driven before checking the fluid
level, it may appear lower than
normal because fluid has traveled
out along the axle tubes and has
not drained back to the sump area.
Therefore, a reading taken

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
372 Vehicle Care
five minutes after the vehicle has
been driven will appear to have a
lower fluid level than a vehicle that
has been stationary for an hour or
two. The rear axle assembly must
be supported on a flat, level surface
to get a true reading.
How to Check Lubricant
2500HD with 6.0L
All Other Series and Engines
To get an accurate reading, the
vehicle should be on a level
surface.
. For all 4.3L and 5.3L 1500
Series applications, the proper
level is 1.0 mm to 19.0 mm
(0.04 in to 0.7 in) below the
bottom of the fill hole, located on
the rear axle. Add only enough
fluid to reach the proper level.
. For 6.2L 1500 Series
applications, the proper level is
from 15 mm to 40 mm (0.6 in to
1.6 in) below the bottom of the fill plug hole, located on the rear
axle. Add only enough fluid to
reach the proper level.
. For all 6.0L 2500HD Series
applications, the proper level is
from 0 mm to 13 mm (0 to 0.5 in)
below the bottom of the fill plug
hole, located on the rear axle.
Add only enough fluid to reach
the proper level.
. For all 6.6L Duramax Diesel
2500HD Series applications and
all 3500 Series applications, the
proper level is from 17 mm to
21 mm (0.6 in to 0.8 in) below
the bottom of the fill plug hole,
located on the rear axle. Add
only enough fluid to reach the
proper level.
What to Use
Refer to Recommended Fluids and
Lubricants 0456 to determine what
kind of lubricant to use.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 373
Noise Control System
Noise Emissions Warranty
General Motors warrants to the first
person who purchases this vehicle
for purposes other than resale and
to each subsequent purchaser that
this vehicle as manufactured by
General Motors, was designed, built
and equipped to conform at the time
it left General Motors’s control with
all applicable U.S. EPA Noise
Control Regulations. This warranty
covers this vehicle as designed,
built and equipped by General
Motors, and is not limited to any
particular part, component or
system of the vehicle manufactured
by General Motors. Defects in
design, assembly or in any part,
component or system of the vehicle
as manufactured by General
Motors, which, at the time it left
General Motors’s control, caused
noise emissions to exceed Federal
standards, are covered by this
warranty for the life of the vehicle. The following information relates to
compliance with federal noise
emission standards for vehicles with
a Gross Vehicle Weight Rating
(GVWR) of more than 4 536 kg
(10,000 lb). The Maintenance
Schedule provides information on
maintaining the noise control system
to minimize degradation of the noise
emission control system during the
life of the vehicle. The noise control
system warranty is given in the
warranty manual.
These standards apply only to
vehicles sold in the United States.
TAMPERING WITH NOISE
CONTROL SYSTEM
PROHIBITED
Federal law prohibits the following
acts or the causing thereof:
1. The removal or rendering inoperative by any person,
other than for purposes of
maintenance, repair,
or replacement, of any device
or element of design
incorporated into any new
vehicle for the purpose of noise control prior to its sale or
delivery to the ultimate
purchaser or while it is in
use; or
2. The use of the vehicle after such device or element of
design has been removed or
rendered inoperative by any
person.
Among those acts presumed to
constitute tampering are the acts
listed below.
Insulation:
Removal of the noise shields or any
underhood insulation.
Engine:
Removal or rendering the engine
speed governor, if equipped,
inoperative so as to allow engine
speed to exceed manufacturer
specifications.
Fan and Drive:
. Removal of the fan clutch,
if equipped, or rendering the
clutch inoperative.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
374 Vehicle Care
.Removal of the fan shroud,
if equipped.
Air Intake:
. Removal of the air cleaner
silencer.
. Modification of the air cleaner.
Exhaust:
. Removal of the muffler and/or
resonator.
. Removal of the exhaust pipes
and exhaust pipe clamps.
Starter Switch Check
{Warning
When you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be sure there is enough room
around the vehicle. 2. Apply both the parking brake
and the regular brake.
Do not use the accelerator
pedal, and be ready to turn off
the engine immediately if it
starts.
3. Try to start the engine in each gear. The vehicle should start
only in P (Park) or N (Neutral).
If the vehicle starts in any other
position, contact your dealer for
service.
Automatic Transmission
Shift Lock Control
Function Check
{Warning
When you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured. 1. Before starting this check, be
sure there is enough room
around the vehicle. It should be
parked on a level surface.
2. Apply the parking brake. Be ready to apply the regular
brake immediately if the vehicle
begins to move.
3. With the engine off, turn the ignition on, but do not start the
engine. Without applying the
regular brake, try to move the
shift lever out of P (Park) with
normal effort. If the shift lever
moves out of P (Park), contact
your dealer for service.
Ignition Transmission
Lock Check
While parked and with the parking
brake set, try to turn the ignition off
in each shift lever position.
.The ignition should turn off only
when the shift lever is in
P (Park).
. The ignition key should come
out only when the ignition is off.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 375
Contact your dealer if service is
required.
Park Brake and P (Park)
Mechanism Check
{Warning
When you are doing this check,
the vehicle could begin to move.
You or others could be injured
and property could be damaged.
Make sure there is room in front
of the vehicle in case it begins to
roll. Be ready to apply the regular
brake at once should the vehicle
begin to move.
Park on a fairly steep hill, with the
vehicle facing downhill. Keeping
your foot on the regular brake, set
the parking brake.
. To check the parking brake's
holding ability: With the engine
running and the transmission in
N (Neutral), slowly remove foot pressure from the regular brake
pedal. Do this until the vehicle is
held by the parking brake only.
. To check the P (Park)
mechanism's holding ability:
With the engine running, shift to
P (Park). Then release the
parking brake followed by the
regular brake.
Contact your dealer if service is
required.
Wiper Blade Replacement
Windshield wiper blades should be
inspected for wear or cracking.
Replacement blades come in
different types and are removed in
different ways. For proper
windshield wiper blade length and
type, see Maintenance
Replacement Parts 0458.
Caution
Allowing the wiper arm to touch
the windshield when no wiper
blade is installed could damage
the windshield. Any damage that
occurs would not be covered by
the vehicle warranty. Do not allow
the wiper arm to touch the
windshield.
To replace the windshield wiper
blade: 1. Pull the windshield wiper assembly away from the
windshield.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
376 Vehicle Care
2. Press the button (2) in themiddle of the wiper arm
connector, and pull the wiper
blade away from the arm
connector (1).
3. Remove the wiper blade.
4. Reverse Steps 1–3 for wiper blade replacement.
Windshield Replacement
Driver Assistance Systems
If the windshield needs to be
replaced and the vehicle is
equipped with a front camera sensor
for the Driver Assistance Systems, a GM replacement windshield is
recommended. The replacement
windshield must be installed
according to GM specifications for
proper alignment. If it is not, these
systems may not work properly, they
may display messages, or they may
not work at all. See your dealer for
proper windshield replacement.
Gas Strut(s)
This vehicle is equipped with gas
strut(s) to provide assistance in
lifting and holding open the hood/
trunk/liftgate system in full open
position.
{Warning
If the gas struts that hold open
the hood, trunk, and/or liftgate fail,
you or others could be seriously
injured. Take the vehicle to your
dealer for service immediately.
Visually inspect the gas struts for
signs of wear, cracks, or other
damage periodically. Check to
(Continued)
Warning (Continued)
make sure the hood/trunk/liftgate
is held open with enough force.
If struts are failing to hold the
hood/trunk/liftgate, do not
operate. Have the vehicle
serviced.
Caution
Do not apply tape or hang any
objects from gas struts. Also do
not push down or pull on gas
struts. This may cause damage to
the vehicle.
See Maintenance Schedule 0448.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 377
Hood
Trunk
Liftgate
Headlamp Aiming
Headlamp aim has been preset and
should need no further adjustment.
If the vehicle is damaged in a crash,
the headlamp aim may be affected.
If adjustment to the headlamps is
necessary, see your dealer.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
378 Vehicle Care
Bulb Replacement
For the proper type of replacement
bulbs, or any bulb changing
procedure not listed in this section,
contact your dealer.
Halogen Bulbs
{Warning
Halogen bulbs have pressurized
gas inside and can burst if you
drop or scratch the bulb. You or
others could be injured. Be sure
to read and follow the instructions
on the bulb package.
High Intensity Discharge
(HID) Lighting
{Warning
The High Intensity Discharge
(HID) lighting system operates at
a very high voltage. If you try to(Continued)
Warning (Continued)
service any of the system
components, you could be
seriously injured. Have your
dealer or a qualified technician
service them.
After an HID headlamp bulb has
been replaced, the beam might be a
slightly different shade than it was
originally. This is normal.
LED Lighting
This vehicle has several LED lamps.
For replacement of any LED lighting
assembly, contact your dealer.
Taillamps, Turn Signal,
Stoplamps, and Back-Up
Lamps
1. Stoplamp/Taillamp/Turn Signal Lamp
2. Back-Up Lamp
3. Sidemarker Lamp
To replace one of these bulbs:
1. Open the tailgate.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 379
2. Remove the two rear lampassembly screws.
3. Pull the rear lamp assembly outboard away from the box
side until the retainers release.
There will be a noise when the
retainers release.4. Pull the rear lamp assemblystraight back to remove it from
the vehicle.
5. Turn the bulb socket counterclockwise.
6. Pull the bulb straight out from the socket.
7. Replace the bulb, then insert the bulb socket into the rear
lamp assembly and turn
clockwise.8. Verify the retainer ring ofattachment stud is pulled away
from lamp. If the retainer ring is
out of position, it will not
engage. Reset the retainer by
pulling it forward with a tool.
9. Push the rear lamp assembly straight in until it is seated
against the vehicle.
10. Make sure the rear lamp assembly is flush with the
box side.
11. Reinstall the two rear lamp assembly screws.