2003 GMC SIERRA Owner's Manual

All-Wheel Drive
Lubricant checks in this section also apply to these
vehicles. However, there are two additional systems that
need lubrication.
Transfer Case
When to Check Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant. SeePart C: Periodic
Maintenance Inspections on page 6-14.
How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.
If the level is below the bottom of thefiller plug hole,
you’ll need to add some lubricant. Add enough lubricant
to raise the level to the bottom of thefiller plug hole.
Use care not to overtighten the plug.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. SeePart D: Recommended
Fluids and Lubricants on page 6-15.
(A) Fill Plug (B) Drain Plug
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Rear Axle
When to Check Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant. SeePart A: Scheduled
Maintenance Services on page 6-4.
How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.The proper level is from 5/8 inch to 1 5/8 inch (15 mm to
40 mm) below the bottom of thefiller plug hole. Add
only enoughfluid to reach the proper level. The proper
level for vehicles with QUADRASTEER™(4 Wheel
Steer) is from 0 to 1/4 inch (0 to 6 mm) below thefiller
plug hole. Add only enoughfluid to reach the proper
level.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. SeePart D: Recommended
Fluids and Lubricants on page 6-15.
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Front Axle
When to Check Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant. See Part A:Part A:
Scheduled Maintenance Services on page 6-4.
How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.If the level is below the bottom of thefiller plug hole,
you may need to add some lubricant.
When the differential is cold, add enough lubricant to
raise the level to 0 to 3/8 inch (9.5 mm) below thefiller
plug hole.
When the differential is at operating temperature
(warm), add enough lubricant to raise the level to the
bottom of thefiller plug hole.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See Part D:Part D:
Recommended Fluids and Lubricants on page 6-15.
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Bulb Replacement
For any bulb changing procedure not listed in this
section, contact your dealer.
SeeReplacement Bulbs on page 5-55for the proper
types of bulbs to use.
Halogen Bulbs
{CAUTION:
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.
Headlamps
1. Your vehicle is equipped with two pins, remove the
two pins on the top of the headlamp assembly.
To remove the pins, turn the outer pin outward and
pull it straight up. To remove the inner pin, turn
it in and pull it straight up.
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A. Low-Beam Headlamp
B. High-Beam Headlamp
2. Pull the headlamp assembly out.
3. Unplug the electrical connector.
4. Turn the old bulb counterclockwise and remove it
from the headlamp assembly.
5. Put the new bulb into the assembly and turn it
clockwise until it is tight. Use care not to touch
the bulb with yourfingers or hands.
6. Plug in the electrical connector.
7. Put the headlamp assembly back into the vehicle.
Install and tighten the two pins.
Front Turn Signal, Sidemarker and
Daytime Running Lamps
A. Sidemarker Lamp
B. Retainer Clip
C. Front Turn Signal Lamp
D. Daytime Running Lamp (DRL)
1. Remove the headlamp assembly as mentioned
previously.
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2. Press the retainer clip (B), located behind the turn
signal housing, towards the outside of the vehicle.
3. Pull the turn signal housing out of the vehicle.4. Press the locking release lever, turn the bulb socket
counterclockwise and remove it from the turn signal
housing.
5. Remove the old bulb from the bulb socket.
6. Put a new bulb into the bulb socket. Use care not
to touch the bulb with yourfingers or hands.
7. Put the bulb socket back into the turn signal
housing and turn it clockwise until it locks.
8. Put the turn signal housing back into the vehicle
placing the hook and posts on the inner side into
the alignment holesfirst, then the outer side into the
retainer bracket until you hear a click.
9. Put the headlamp assembly back into the vehicle.
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Roof Marker Lamps
1. Remove the two
screws and lift off
the lens.2. Remove the six screws on the center roof marker
lamps.
3. Turn the old bulb counterclockwise to remove it
from the socket.
4. Put a new bulb into the
socket and turn
clockwise until it locks
in place.
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5. Reinstall the lens and tighten the screws.
Center High-Mounted Stoplamp
(CHMSL) and Cargo Lamp
1. Remove the screws and lift off the lamp assembly.
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