2007 CHEVROLET COLORADO Owners Manual

Weight of the Trailer Tongue
The tongue load (A) of any trailer is an important
weight to measure because it affects the total
or gross weight of your vehicle. The Gross Vehicle
Weight (GVW) includes the curb weight of the
vehicle, any cargo you may carry in it, and
the people who will be riding in the vehicle. If you
have a lot of options, equipment, passengers
or cargo in your vehicle, it will reduce the tongue
weight your vehicle can carry, which will also
reduce the trailer weight your vehicle can tow.
And if you will tow a trailer, you must add
the tongue load to the GVW because your vehicle
will be carrying that weight, too. SeeLoading
Your Vehicle on page 293for more information
about your vehicle’s maximum load capacity.The trailer tongue weight (A) should be 10 percent
to 15 percent of the total loaded trailer weight,
up to a maximum of 500 lbs (226 kg) with a weight
carrying hitch.
Do not exceed the maximum allowable tongue
weight for your 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.
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After you’ve loaded your trailer, weigh the trailer
and then the tongue, separately, to see if the
weights are proper. If they aren’t you may be able
to get them right simply by moving some of the
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 your 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:
You can 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 will be 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).
But let’s say your specic vehicle is equipped with
some of the latest options and you have a front
seat passenger and two rear seat passengers
with some luggage and gear in the vehicle as well.
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You may add 300 lbs (136 kg) to the front axle
weight and 400 lbs (181 kg) to the rear axle weight.
Your vehicle now weighs:
Weight is still below 7,200 lbs (3 266 kg) and you
may think that you should subtract 700 additional
pounds (318 kg) from your trailering capacity to
stay within GCWR limits. Your maximum trailer
would only be 7,800 lbs (3 538 kg). You may go
further and think you must limit tongue weight to
less than 1,000 lbs (454 kg) to avoid exceeding
GVWR. But, you must still consider the effect
on the rear axle. Because your rear axle now
weighs 3,100 lbs (1 406 kg), you can only put
900 lbs (408 kg) 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 you with being able to
handle only 600 lbs (272 kg) of tongue weight.Since tongue weight is usually at least 10 percent
of total loaded trailer weight, you can expect that
the largest trailer your vehicle can properly handle
is 6,000 lbs (2 721 kg).
It is important that you make sure your vehicle
does not exceed any of its ratings — GCWR,
GVWR, RGAWR, Maximum Trailer Rating or
Tongue Weight. The only way to be sure you are
not exceeding any of these ratings is to weigh
your vehicle and trailer.
Total Weight on Your Vehicle’s Tires
Be sure your vehicle’s tires are inated to the upper
limit for cold tires. You’ll nd these numbers on the
Certication/Tire label located at the bottom of the
center pillar on the driver’s side of the vehicle, or
seeLoading Your Vehicle on page 293. Then be
sure you don’t go over the GVWR limit for your
vehicle, including the weight of the trailer tongue.
Hitches
It’s important to have the correct hitch equipment.
Crosswinds, large trucks going by and rough roads
are a few reasons why you’ll need the right hitch.
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Weight-Distributing Hitches and
Weight Carrying Hitches
You can use your step bumper hitch for trailers
up to 2,000 lbs (907 kg) total weight, and
200 lbs (90 kg) tongue weight.
Notice:If you use a step-bumper hitch, your
bumper could be damaged in sharp turns.
Make sure you have ample room when turning
to avoid contact between the trailer and
the bumper.
Safety Chains
You should always attach chains between your
vehicle and your 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. Instructions about safety
chains may be provided by the hitch manufacturer
or by the trailer manufacturer. For trailers up to
2,000 lbs (907 kg) you may attach the safety chains
to the attaching points on the bumper. For heavier
trailers, follow the trailer or hitch manufacturer’s
recommendation for attaching safety chains.
Always leave just enough slack so you can turn
with your rig. Never allow safety chains to drag
on the ground.
Trailer Brakes
If your trailer weighs more than 1,000 lbs (450 kg)
loaded, then it needs its own brakes — and they
must be adequate. Be sure to read and follow the
instructions for the trailer brakes so you’ll be able
to install, adjust and maintain them properly.
Your trailer’s brake system can tap into the
vehicle’s hydraulic brake system only if:
The trailer parts can withstand
3,000 psi (20 650 kPa) of pressure.
The trailer’s brake system will use less
than 0.02 cubic inch (0.3 cc) of uid from
your vehicle’s master cylinder. Otherwise,
both braking systems won’t work well.
You could even lose your brakes.
If everything checks out this far, then make the
brake uid tap at the port on the master cylinder
that sends uid to the rear brakes. But don’t
use copper tubing for this. If you do, it will bend
and nally break off. Use steel brake tubing.
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Driving with a Trailer
Towing a trailer requires a certain amount of
experience. Before setting out for the open road,
you’ll want to get to know your rig. Acquaint
yourself 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 a good deal longer and not nearly
as responsive as your vehicle is by itself.
Before you start, check all trailer hitch parts and
attachments, safety chains, electrical connector,
lamps, tires and mirror adjustment. If the trailer
has electric brakes, start your vehicle and
trailer moving and then apply the trailer brake
controller by hand to be sure the brakes are
working. This lets you check your electrical
connection at the same time.
During your 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 your vehicle without
a trailer. This can help you avoid situations
that require heavy braking and sudden turns.
Passing
You’ll need more passing distance up ahead when
you’re towing a trailer. And, because you’re a
good deal longer, you’ll need to go much farther
beyond the passed vehicle before you can
return to your lane.
Backing Up
Hold the bottom of the steering wheel with
one hand. Then, to move the trailer to the left,
just 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.
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Making Turns
Notice:Making very sharp turns while
trailering could cause the trailer to come in
contact with the vehicle. Your vehicle could
be damaged. Avoid making very sharp
turns while trailering.
When you’re turning with a trailer, make wider turns
than normal. Do this so your trailer won’t 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
When you tow a trailer, your vehicle has to have
extra wiring and a heavy-duty turn signal asher.
The arrows on your instrument panel will ash
whenever you signal a turn or lane change.
Properly hooked up, the trailer lamps will also
ash, telling other drivers you’re about to
turn, change lanes or stop.
When towing a trailer, the arrows on your
instrument panel will ash for turns even if
the bulbs on the trailer are burned out.Thus, you may think drivers behind you are seeing
your signal when they are not. It’s important to
check occasionally to be sure the trailer bulbs are
still working.
Driving On Grades
Reduce speed and shift to a lower gear before
you start down a long or steep downgrade.
If you don’t shift down, you might have to use
your brakes so much that they would get hot
and no longer work well.
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 you turn your engine off immediately
after towing at high altitude on steep uphill grades,
your 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 PARK (P) (or
the manual transmission out of gear and the
parking brake applied) for a few minutes before
turning the engine off. If you do get the overheat
warning, seeEngine Overheating on page 348.
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Parking on Hills
{CAUTION:
You really should not park your
vehicle, with a trailer attached, on a hill.
If something goes wrong, your rig could
start to move. People can be injured,
and both your vehicle and the trailer
can be damaged.
But if you ever have to park your rig on a hill,
here’s how to do it:
1. Apply your regular brakes, but don’t shift into
PARK (P) yet, or into gear for a manual
transmission. When parking uphill, turn your
wheels away from the curb. When parking
downhill, turn your wheels into the curb.
2. Have someone place chocks under the
trailer wheels.
3. When the wheel chocks are in place,
release the regular brakes until the
chocks absorb the load.4. Reapply the regular brakes. Then apply your
parking brake, and then shift into PARK (P),
or REVERSE (R) for a manual transmission.
SeeParking Brake on page 133for more
information.
5. If you have a four-wheel-drive vehicle, be
sure the transfer case is in a drive gear
and not in NEUTRAL. SeeFour-Wheel
Drive on page 129for more information.
6. Release the regular brakes.
When You Are Ready to Leave
After Parking on a Hill
1. Apply your regular brakes and hold the
pedal down while you:
start your 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.
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Maintenance When Trailer Towing
Your vehicle will need service more often
when you’re pulling a trailer. SeeScheduled
Maintenance on page 442for more on this.
Things that are especially important in trailer
operation are automatic transmission uid
(don’t overll), engine oil, axle lubricant, belt,
cooling system and brake system. Each of these
is covered in this manual, and the Index will
help you nd them quickly. If you’re trailering,
it’s a good idea to review these sections before
you start your trip.
Check periodically to see that all hitch nuts
and bolts are tight.
Trailer Wiring Harness
Your vehicle may be equipped with a four-pin
trailer towing harness. This harness has a four-pin
trailer connector that is attached to a bracket on
the hitch platform. The four-wire harness contains
the following trailer circuits:
Yellow: Left Stop/Turn Signal
Green: Right Stop/Turn Signal
Brown: Taillamps/Park lamps
White: Ground
Trailer Recommendations
You must subtract your hitch load from the CWR
for your vehicle. Weigh your vehicle with your trailer
attached, so that you won’t go over the GVWR or
the GAWR.
You’ll get the best performance if you spread
out the weight of your load the right way, and if
you choose the correct hitch and trailer brakes.
For more information, seeTowing a Trailer
on page 306later in this section.
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