
Dinghy Towing
Two-Wheel-Drive Vehicles
Notice:If the vehicle is towed with all four wheels
on the ground, the drivetrain components could
be damaged. The repairs would not be covered by
the vehicle warranty. Do not tow the vehicle with
all four wheels on the ground.
Two-wheel-drive vehicles should not be towed with
all four wheels on the ground. Two-wheel-drive
transmissions have no provisions for internal
lubrication while being towed.
All-Wheel-Drive Vehicles
The vehicle was not designed to be towed with all four
wheels on the ground. To properly tow these vehicles,
they should be placed on a platform trailer with all
four wheels off the ground.
Notice:Towing an all-wheel-drive vehicle with all
four wheels on the ground, or even with only two of
its wheels on the ground, will damage drivetrain
components. Do not tow an all-wheel-drive vehicle
with any of its wheels on the ground.
Dolly Towing
Rear Towing (Rear Wheels Off the Ground)
Two-Wheel-Drive Vehicles
Use the following procedure to tow the vehicle from
the rear:
1. Attach the dolly to the tow vehicle following the
dolly manufacturer’s instructions.
2. Drive the rear wheels onto the dolly.
3. Firmly set the parking brake. SeeParking Brake on
page 2-26for more information.
4. Put the transmission in P (Park).
5. Secure the vehicle to the dolly following the
manufacturer’s instructions.
6. Use an adequate clamping device designed for
towing to ensure that the front wheels are locked
into the straight position.
7. Turn the ignition to LOCK/OFF.
If the tow vehicle will not be started or driven for
six weeks or more, remove the battery cable
from the negative terminal (post) of the battery to
prevent the battery from draining while towing.
4-25

All-Wheel-Drive Vehicles
The vehicle was not designed to be towed with two
wheels on the ground. To properly tow these vehicles,
they should be placed on a platform trailer with all
four wheels off the ground.
Notice:Towing an all-wheel-drive vehicle with all
four wheels on the ground, or even with only two of
its wheels on the ground, will damage drivetrain
components. Do not tow an all-wheel-drive vehicle
with any of its wheels on the ground.
Towing a Trailer
If the vehicle has a diesel engine, see the DURAMAX®
Diesel manual for more information.
{CAUTION:
The driver can lose control when pulling a trailer if
the correct equipment is not used or the vehicle is
not driven properly. For example, if the trailer is
too heavy, the brakes may not work well — or
even at all. The driver and passengers could be
CAUTION: (Continued)
CAUTION: (Continued)
seriously injured. The vehicle may also be
damaged; the resulting repairs would not be
covered by the vehicle warranty. Pull a trailer only
if all the steps in this section have been followed.
Ask your dealer/retailer for advice and information
about towing a trailer with the vehicle.
Notice:Pulling a trailer improperly can damage the
vehicle and result in costly repairs not covered
by the vehicle warranty. To pull a trailer correctly,
follow the advice in this section and see your
dealer/retailer for important information about
towing a trailer with the vehicle.
To identify the trailering capacity of the vehicle, read the
information in “Weight of the Trailer” that appears
later in this section.
Trailering is different than just driving the vehicle by itself.
Trailering means changes in handling, acceleration,
braking, durability and fuel economy. Successful, safe
trailering takes correct equipment, and it has to be used
properly.
4-26

Use the following chart to determine how much the vehicle can weigh, based upon the vehicle model and options.
Vehicle Axle Ratio Maximum Trailer Weight GCWR*
G1500 Cargo Van 2WD
4.3L V6 3.42 4,400 lbs (1 996 kg) 9,500 lbs (4 309 kg)
5.3L V83.42
3.736,700 lbs (3 039 kg) 12,000 lbs (5 443 kg)
H1500 Cargo Van AWD
5.3L V8 3.42 6,500 lbs (2 948 kg) 12,000 lbs (5 443 kg)
G1500 Passenger Van 2WD
5.3L V8 3.73 6,200 lbs (2 812 kg) 12,000 lbs (5 443 kg)
H1500 Passenger Van AWD
5.3L V8 3.73 6,000 lbs (2 722 kg) 12,000 lbs (5 443 kg)
G2500 Cargo Van 2WD Short Wheelbase
4.8L V83.73
4.106,400 lbs (2 903 kg)
7,400 lbs (3 357 kg)12,000 lbs (5 443 kg)
13,000 lbs (5 897 kg)
6.0L V83.73
4.108,400 lbs (3 810 kg)
10,000 lbs (4 536 kg)14,000 lbs (6 350 kg)
16,000 lbs (7 257 kg)
G2500 Cargo Van 2WD Long Wheelbase
4.8L V83.73
4.106,200 lbs (2 812 kg)
7,200 lbs (3 266 kg)12,000 lbs (5 443 kg)
13,000 lbs (5 897 kg)
6.0L V83.73
4.108,200 lbs (3 719 kg)
10,000 lbs (4 536 kg)14,000 lbs (6 350 kg)
16,000 lbs (7 257 kg)
G2500 Passenger Van 2WD Short Wheelbase
6.0L V8 3.73 7,600 lbs (3 447 kg) 14,000 lbs (6 350 kg)
6.0L V8 4.10 10,000 lbs (4 536 kg) 16,000 lbs (7 257 kg)
4-28

Vehicle Axle Ratio Maximum Trailer Weight GCWR*
G3500 Cargo Van 2WD Short Wheelbase
4.8L V83.73
4.106,400 lbs (2 903 kg)
9,400 lbs (4 264 kg)12,000 lbs (5 443 kg)
13,000 lbs (5 897 kg)
6.0L V83.73
4.108,400 lbs (3 810 kg)
10,000 lbs (4 536 kg)14,000 lbs (6 350 kg)
16,000 lbs (7 257 kg)
G3500 Cargo Van 2WD Long Wheelbase
4.8L V83.73
4.106,100 lbs (2 767 kg)
7,100 lbs (3 221 kg)12,000 lbs (5 443 kg)
13,000 lbs (5 897 kg)
6.0L V83.73
4.108,200 lbs (3 719 kg)
10,000 lbs (4 536 kg)14,000 lbs (6 350 kg)
16,000 lbs (7 257 kg)
G3500 Passenger Van 2WD Short Wheelbase
6.0L V8 3.73 7,600 lbs (3 447 kg) 14,000 lbs (6 350 kg)
G3500 Passenger Van 2WD Long Wheelbase
6.0L V8 3.73 7,300 lbs (3 311 kg) 14,000 lbs (6 350 kg)
*The Gross Combined Weight Rating (GCWR) is the total allowable weight of the completely loaded vehicle and
trailer including any passengers, cargo equipment and conversion. The GCWR for the vehicle should not be
exceeded.
Ask your dealer/retailer for our trailering information or advice, or write us at our Customer Assistance Offices.
SeeCustomer Assistance Offices on page 7-6for more information.
4-29

Towing a trailer requires a certain amount of experience.
Get to know the rig before setting out for the open
road. Get acquainted with the feel of handling and
braking with the added weight of the trailer. And always
keep in mind that the vehicle you are driving is now
longer and not as responsive as the vehicle is by itself.
Before starting, check all trailer hitch parts and
attachments, safety chains, electrical connectors, lamps,
tires and mirror adjustments. If the trailer has electric
brakes, start the vehicle and trailer moving and then
apply the trailer brake controller by hand to be sure the
brakes are working. This checks the electrical connection
at the same time.
During the trip, check occasionally to be sure that the
load is secure, and that the lamps and any trailer brakes
are still working.
Following Distance
Stay at least twice as far behind the vehicle ahead as
you would when driving the vehicle without a trailer.
This can help to avoid situations that require heavy
braking and sudden turns.
Passing
More passing distance is needed when towing a trailer.
Because the rig is longer, it is necessary to go much
farther beyond the passed vehicle before returning to
the lane.
Backing Up
Hold the bottom of the steering wheel with one hand.
Then, to move the trailer to the left, move that hand
to the left. To move the trailer to the right, move your
hand to the right. Always back up slowly and, if possible,
have someone guide you.
Making Turns
Notice:Making very sharp turns while trailering
could cause the trailer to come in contact with the
vehicle. The vehicle could be damaged. Avoid
making very sharp turns while trailering.
When turning with a trailer, make wider turns than
normal. Do this so the trailer will not strike soft shoulders,
curbs, road signs, trees or other objects. Avoid jerky or
sudden maneuvers. Signal well in advance.
Turn Signals When Towing a Trailer
The arrows on the instrument panel flash whenever
signaling a turn or lane change. Properly hooked up, the
trailer lamps also flash, telling other drivers the vehicle
is turning, changing lanes or stopping.
When towing a trailer, the arrows on the instrument panel
flash for turns even if the bulbs on the trailer are burned
out. For this reason you may think other drivers are
seeing the signal when they are not. It is important to
check occasionally to be sure the trailer bulbs are still
working.
4-35

Driving On Grades
Reduce speed and shift to a lower gearbeforestarting
down a long or steep downgrade. If the transmission is
not shifted down, the brakes might have to be used so
much that they would get hot and no longer work well.
The vehicle can tow in D (Drive). Shift the transmission to
a lower gear if the transmission shifts too often under
heavy loads and/or hilly conditions.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If the engine is
turned off immediately after towing at high altitude on
steep uphill grades, the vehicle may show signs similar to
engine overheating. To avoid this, let the engine run while
parked, preferably on level ground, with the automatic
transmission in P (Park) for a few minutes before turning
the engine off. If the overheat warning comes on, see
Engine Overheating on page 5-31.
Parking on Hills
{CAUTION:
Parking the vehicle on a hill with the trailer attached
can be dangerous. If something goes wrong, the rig
could start to move. People can be injured, and
both the vehicle and the trailer can be damaged.
When possible, always park the rig on a flat
surface.
If parking the rig on a hill:
1. Press the brake pedal, but do not shift into P (Park)
yet for vehicles with an automatic transmission, or
into gear for vehicles with a manual transmission.
Turn the wheels into the curb if facing downhill
or into traffic if facing uphill.
2. Have someone place chocks under the trailer
wheels.
4-36

3. When the wheel chocks are in place, release the
brake pedal until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking
brake and shift into P (Park) for vehicles with an
automatic transmission or into gear for vehicles with
a manual transmission.
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal while you:
•start the engine,
•shift into a gear, and
•release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the
chocks.
Maintenance When Trailer Towing
The vehicle needs service more often when pulling a
trailer. See this manual’s Maintenance Schedule or Index
for more information. Things that are especially important
in trailer operation are automatic transmission fluid,
engine oil, axle lubricant, belts, cooling system and brake
system. It is a good idea to inspect these before and
during the trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
The optional heavy-duty trailer wiring package includes
a wiring harness, with a seven-pin connector at the
rear of the vehicle and a four-wire harness assembly
under the driver side of the instrument panel. The
four-wire harness assembly comes without a connector.
If the vehicle does not have a trailer hitch, the
seven-wire harness assembly with connector is taped
together and located in a frame pocket at the driver side
rear left corner of the frame.
4-37

Service............................................................5-3
Accessories and Modifications..........................5-3
California Proposition 65 Warning.....................5-4
California Perchlorate Materials Requirements......5-4
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of the
Vehicle......................................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-6
Gasoline Specifications....................................5-6
California Fuel...............................................5-6
Additives.......................................................5-7
Fuel E85 (85% Ethanol)..................................5-8
Fuels in Foreign Countries...............................5-9
Filling the Tank............................................5-10
Filling a Portable Fuel Container.....................5-12
Checking Things Under the Hood....................5-12
Hood Release..............................................5-13
Engine Compartment Overview.......................5-14
Engine Oil...................................................5-15
Engine Oil Life System..................................5-18
Engine Air Cleaner/Filter................................5-20
Automatic Transmission Fluid.........................5-21
Cooling System............................................5-24
Engine Coolant.............................................5-25Radiator Pressure Cap..................................5-31
Engine Overheating.......................................5-31
Engine Fan Noise.........................................5-33
Power Steering Fluid.....................................5-34
Windshield Washer Fluid................................5-35
Brakes........................................................5-36
Battery........................................................5-39
Jump Starting...............................................5-40
All-Wheel Drive..............................................5-44
Rear Axle
.......................................................5-45
Front Axle......................................................5-46
Noise Control System.....................................5-47
Tampering with Noise Control System
Prohibited.................................................5-47
Bulb Replacement..........................................5-48
Halogen Bulbs..............................................5-48
Headlamps..................................................5-48
Front Turn Signal, Sidemarker and
Parking Lamps..........................................5-50
Center High-Mounted
Stoplamp (CHMSL)....................................5-51
Taillamps.....................................................5-51
Replacement Bulbs.......................................5-52
Windshield Wiper Blade Replacement..............5-53
Section 5 Service and Appearance Care
5-1