CHEVROLET EXPRESS 2007 Owners Manual

Vehicle Axle Ratio Maximum Trailer Weight GCWR*
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 9,600 lbs (4 355 kg) 16,000 lbs (7 257 kg)
G3500 Cargo Van 2WD Short Wheelbase
4.8L V83.73
4.106,400 lbs (2 903 kg)
7,400 lbs (3 295 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 8-6
for more information.
5-33

Weight of the Trailer Tongue
The tongue load (A) of any trailer is an important weight
to measure because it affects the total gross weight
of the vehicle. The Gross Vehicle Weight (GVW)
includes the curb weight of the vehicle, any cargo
carried in it, and the people who will be riding in the
vehicle. If there are a lot of options, equipment,
passengers or cargo in the vehicle, it will reduce the
tongue weight the vehicle can carry, which will also
reduce the trailer weight the vehicle can tow. If towing a
trailer, the tongue load must be added to the GVW
because the vehicle will be carrying that weight, too. See
Loading the Vehicle on page 5-19for more information
about the vehicle’s maximum load capacity.The trailer tongue weight (A) should be 10 percent to
15 percent of the total loaded trailer weight (B), up to a
maximum of 400 lbs (181 kg) with a weight carrying
hitch. The trailer tongue weight (A) should be 10 percent
to 15 percent of the total loaded trailer weight (B), up
to a maximum of 1,000 lbs (454 kg) with a weight
distributing hitch.
5-34

Do not exceed the maximum allowable tongue weight
for the vehicle. Choose the shortest hitch extension that
will position the hitch ball closest to the vehicle. This
will help reduce the effect of trailer tongue weight on the
rear axle.
After loading the trailer, weigh the trailer and then the
tongue, separately, to see if the weights are proper.
If they are not, adjustments might be made by moving
some items around in the trailer.
Trailering may be limited by the vehicle’s ability to carry
tongue weight. Tongue weight cannot cause the
vehicle to exceed the GVWR (Gross Vehicle Weight
Rating) or the RGAWR (Rear Gross Axle Weight
Rating). The effect of additional weight may reduce the
trailering capacity more than the total of the additional
weight.Consider the following example:
A vehicle model base weight is 5,500 lbs (2 495 kg);
2,800 lbs (1 270 kg) at the front axle and 2,700 lbs
(1 225 kg) at the rear axle. It has a GVWR of 7,200 lbs
(3 266 kg), a RGAWR of 4,000 lbs (1 814 kg) and a
GCWR (Gross Combination Weight Rating) of
14,000 lbs (6 350 kg). The trailer rating should be:
Expect tongue weight to be at least 10 percent of trailer
weight (850 lbs (386 kg)) and because the weight is
applied well behind the rear axle, the effect on the rear
axle is greater than just the weight itself, as much as
1.5 times as much. The weight at the rear axle could be
850 lbs (386 kg) X 1.5 = 1,275 lbs (578 kg). Since the
rear axle already weighs 2,700 lbs (1 225 kg), adding
1,275 lbs (578 kg) brings the total to 3,975 lbs (1 803 kg).
This is very close to, but within the limit for RGAWR as
well. The vehicle is set to trailer up to 8,500 lbs
(3 856 kg).
5-35

If the vehicle has many options and there is a front seat
passenger and two rear seat passengers with some
luggage and gear in the vehicle as well. 300 lbs (136 kg)
could be added to the front axle weight and 400 lbs
(181 kg) to the rear axle weight. The vehicle now weighs:
Weight is still below 7,200 lbs (3 266 kg) and you might
think 700 additional pounds (318 kg) should be
subtracted from the trailering capacity to stay within
GCWR limits. The maximum trailer would only be
7,800 lbs (3 538 kg). You may go further and think the
tongue weight should be limited to less than 1,000 lbs
(454 kg) to avoid exceeding GVWR. But the effect on the
rear axle must still be considered. Because the rear axle
now weighs 3,100 lbs (1 406 kg), 900 lbs (408 kg) can be
put on the rear axle without exceeding RGAWR. The
effect of tongue weight is about 1.5 times the actual
weight. Dividing the 900 lbs (408 kg) by 1.5 leaves only
600 lbs (272 kg) of tongue weight that can be handled.
Since tongue weight is usually at least 10 percent of total
loaded trailer weight, expect that the largest trailer the
vehicle can properly handle is 6,000 lbs (2 721 kg).It is important that the vehicle does not exceed any of
its ratings — GCWR, GVWR, RGAWR, Maximum Trailer
Rating or Tongue Weight. The only way to be sure it
is not exceeding any of these ratings is to weigh
the vehicle and trailer.
Total Weight on the Vehicle’s Tires
Be sure the vehicle’s tires are inflated to the upper limit
for cold tires. These numbers can be found on the
Certification label at the rear edge of the driver’s door or
seeLoading the Vehicle on page 5-19. Make sure not
to go over the GVW limit for the vehicle, or the GAWR,
including the weight of the trailer tongue. If using a
weight distributing hitch, make sure not to go over the
rear axle limit before applying the weight distribution
spring bars.
Hitches
It is important to have the correct hitch equipment.
Crosswinds, large trucks going by and rough roads are
a few reasons why the right hitch is needed.
5-36

Weight-Distributing Hitches and Weight
Carrying Hitches
A:Body to Ground Distance
B:Front of Vehicle
When using a weight-distributing hitch, the hitch must
be adjusted so the distance (A) remains the same both
before and after coupling the trailer to the tow vehicle.
If a step-bumper hitch will be used, the bumper could be
damaged in sharp turns. Make sure there is ample
room when turning to avoid contact between the trailer
and the bumper.If the loaded trailer being pulled will weigh more than
5,000 lbs (2 270 kg), be sure to use a properly mounted
weight-distributing hitch and sway control of the proper
size. This equipment is very important for proper vehicle
loading and good handling when driving. Always use a
sway control if the trailer will weigh more than these
limits. Ask a hitch dealer about sway controls.
Will any holes need to be made in the body of the
vehicle when a trailer hitch is installed?
If using the wiring provided with the factory-installed
trailering package, no holes need to be made in
the body of the vehicle. However, if an aftermarket hitch
is installed, holes may need to be made in the body.
If holes are made in the body, then be sure to seal the
holes later when the hitch is removed. If the holes
are not sealed, deadly carbon monoxide (CO) from the
engine’s exhaust can get into the vehicle as well as
dirt and water. See “Carbon Monoxide” underEngine
Exhaust on page 3-40.
Safety Chains
Always attach chains between the vehicle and the
trailer. Cross the safety chains under the tongue of the
trailer to help prevent the tongue from contacting
the road if it becomes separated from the hitch. Always
leave just enough slack so the rig can turn. Never
allow safety chains to drag on the ground.
5-37

Tow/Haul Mode
Pressing this button at
the end of the shift lever
turns on and off the
tow/haul mode.
This indicator light on the
instrument panel cluster
comes on when the
tow/haul mode is on.
Tow/Haul is a feature that assists when pulling a heavy
trailer or a large or heavy load. SeeTow/Haul Mode
on page 3-34for more information.Tow/Haul is designed to be most effective when the
vehicle and trailer combined weight is at least 75 percent
of the vehicle’s Gross Combined Weight Rating (GCWR).
See “Weight of the Trailer” later in the section. Tow/Haul
is most useful under the following driving conditions:
•When pulling a heavy trailer or a large or heavy load
through rolling terrain.
•When pulling a heavy trailer or a large or heavy load
in stop and go traffic.
•When pulling a heavy trailer or a large or heavy load
in busy parking lots where improved low speed
control of the vehicle is desired.
Operating the vehicle in Tow/Haul when lightly loaded or
with no trailer at all will not cause damage. However,
there is no benefit to the selection of Tow/Haul when the
vehicle is unloaded. Such a selection when unloaded
may result in unpleasant engine and transmission driving
characteristics and reduced fuel economy. Tow/Haul is
recommended only when pulling a heavy trailer or a large
or heavy load.
Trailer Brakes
A loaded trailer that weighs more than 1,500 lbs
(680 kg) needs to have its own brake system that is
adequate for the weight of the trailer. Be sure to read
and follow the instructions for the trailer brakes so
they are installed, adjusted and maintained properly.
5-38

Driving with a Trailer
{WARNING:
When towing a trailer, exhaust gases may collect
at the rear of the vehicle and enter if the liftgate,
trunk/hatch, or rear-most window is open.
Engine exhaust contains carbon monoxide (CO)
which cannot be seen or smelled. It can cause
unconsciousness and even death.
To maximize safety when towing a trailer:
•Have the exhaust system inspected for leaks
and make necessary repairs before starting
a trip.
•Never drive with the liftgate, trunk/hatch, or
rear-most window open.
•Fully open the air outlets on or under the
instrument panel.
•Adjust the Climate Control system to a setting
that brings in only outside air and set the fan
speed to the highest setting. See Climate
Control System in the Index.
For more information about carbon monoxide, see
Engine Exhaust on page 3-40Towing 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.
5-39

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.
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 6-35.
5-40

Parking on Hills
{WARNING:
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 the
transmission into P (Park) yet. Turn the wheels into
the curb if facing downhill or into traffic if facing
uphill.
2. Have someone place chocks under the trailer
wheels.
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).
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.
5-41

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.
If the vehicle has a trailer hitch, the seven-wire harness
assembly with connector is attached to a bracket on
the hitch platform. In both cases, the seven-wire harness
has a connector and includes a 30-amp feed wire.
The seven-wire harness connector contains the following
trailer circuits:
•Light Green: Back-up Lamps (10A fuse)**
•White: Ground
•Dark Blue: Trailer Brake Signal
•Dark Green: Right Rear Stop and Turn Signal*
•Red/Black Stripe: Battery Feed (30A Fuse)
•Brown: Trailer Park Lamp Supply Voltage
(15A fuse)**
•Yellow: Left Rear Stop and Turn Signal *
The four-wire harness (without connector) contains the
following circuits:
•Black: Ground
•Red/White: Battery Feed
•Dark Blue: Trailer Brake Signal
•Light Blue: CHMSL/Stoplamp Supply Voltage
* If the vehicle is a cutaway with trailer provisions, a
15 amp fuse will be shared for both left/stop trailer turn
and right/stop trailer turn signals. However, the
cutaway lighting connector will have a 10 amp fuse for
each signal.
** If the vehicle is a cutaway with trailer provisions, a
15 amp fuse will be shared for trailer park lamps
and cutaway rear lighting connector park lamps. Also, a
10 amp fuse will be shared for trailer back-up lamps
and cutaway rear lighting connector back-up lamps.
5-42