engine CHEVROLET SILVERADO 1999 1.G Repair Manual

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4-54
Your vehicle can tow a trailer. If yours was built with
trailering options, as many are, it's ready for heavier
trailers. But trailering is different than just driving your
vehicle by itself. Trailering means changes in handling,
durability and fuel economy. Successful, safe trailering
takes correct equipment, and it has to be used properly.
That's the reason for this part. In it are many
time
-tested, important trailering tips and safety rules.
Many of these are important for your safety and that of
your passengers. So please read this section carefully
before you pull a trailer.
If You Do Decide To Pull A Trailer
If you do, here are some important points:

There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
your rig will be legal, not only where you live but
also where you'll be driving. A good source for this
information can be state or provincial police.

Consider using a sway control if your trailer will
weigh less than the capacity stamped on your step
bumper. You should always use a sway control if
your trailer will weigh more than the capacity
stamped on your step bumper. You can ask a hitch
dealer about sway controls.
Don't tow a trailer at all during the first 500 miles
(800 km) your new vehicle is driven. Your engine,
axle or other parts could be damaged.

Then, during the first 500 miles (800 km) that you
tow a trailer, don't drive over 50 mph (80 km/h) and
don't make starts at full throttle. This helps your
engine and other parts of your vehicle wear in at the
heavier loads.

If you have an automatic transmission, you can
tow in DRIVE (D). You may want to shift the
transmission to THIRD (3) or, if necessary, a lower
gear selection if the transmission shifts too often
(e.g., under heavy loads and/or hilly conditions).
See ªTow/Haul Modeº in the Index. If you have a
manual transmission and you are towing a trailer, it's
better not to use FIFTH (5) gear. Just drive in
FOURTH (4) gear (or, as you need to, a lower gear).
Three important considerations have to do with weight:

the weight of the trailer,

the weight of the trailer tongue

and the weight on your vehicle's tires.

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Tow/Haul Mode (If Equipped)
Tow/haul is a feature on automatic transmission
equipped vehicles that assists when pulling a heavy
trailer or a large or heavy load. The purpose of the
tow/haul mode is to:

Reduce the frequency and improve the predictability
of transmission shifts when pulling a heavy trailer or
a large or heavy load.

Provide the same solid shift feel when pulling a
heavy trailer or a large or heavy load as when the
vehicle is unloaded.

Improve control of vehicle speed while requiring less
throttle pedal activity when pulling a heavy trailer or
a large or heavy load.
Automatic transmission equipped vehicles are provided
with a button at the end of the shift lever which when
pressed enables tow/haul. When the button is pressed, a
light on the instrument panel will illuminate to indicate
that tow/haul has been selected. Tow/haul may be turned
off by pressing the button again, at which time the
indicator light on the instrument panel will turn off. The
vehicle will automatically turn off tow/haul every time it
is started.Tow/haul is designed to be most effective when the
vehicle and trailer combined weight is at least 75% of
the vehicle's Gross Combined Weight Rating (GCWR).
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.

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4-56 Weight of the Trailer
How heavy can a trailer safely be?
It depends on how you plan to use your rig. For example,
speed, altitude, road grades, outside temperature and how
much your vehicle is used to pull a trailer are all
important. And, it can also depend on any special
equipment that you have on your vehicle.
Use one of the following charts to determine how much
your vehicle can weigh, based upon your vehicle model
and options.
Maximum trailer weight is calculated assuming the
driver and one passenger are in the tow vehicle and it
has all the required trailering equipment. The weight of
additional optional equipment, passengers and cargo in
the tow vehicle must be subtracted from the maximum
trailer weight.
Above the 5,000 lbs. (2 268 kg) trailer rating, the
handling/trailering suspension is required on
C
-1500 models and the handling/trailering or off-road
suspension is required on K
-1500 models. The engine
oil cooler and the heavy
-duty trailering package is required
on C/K
-2500 models with the VORTEC 6000 engine.C
-1500 (2WD)*
Engine (Trans.) Axle
RatioMax. Trailer Wt.
4300 V6 (Auto) 3.08 4,000 lbs. (1 814 kg)
3.42 4,500 lbs. (2 041 kg)
3.73 5,000 lbs. (2 268 kg)
4300 V6 (Manual)3.08 3,500 lbs. (1 588 kg)
3.42 4,000 lbs. (1 814 kg)
4800 V8 (Auto) 3.42 6,000 lbs. (2 722 kg)
3.73 7,000 lbs. (3 175 kg)
4800 V8 (Manual)3.42 4,000 lbs. (1 814 kg)
3.73 5,000 lbs. (2 268 kg)
5300 V8 3.42 7,000 lbs. (3 175 kg)
3.73 8,200 lbs. (3 720 kg)
* Weight distributing hitch tongue weight 10% to
15% of hitch pulling weight 1,000 lb. (454 kg)
maximum. Fifth
-wheel hitch tongue weight 15% to
25% of hitch pulling weight 1,500 lb (680 kg) maximum.

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K-1500 (4WD)*
Engine (Trans.) Axle
RatioMax. Trailer Wt.
4300 V6 (Auto) 3.42 4,000 lbs. (1 814 kg)
3.73 4,500 lbs. (2 041 kg)
4300 V6 (Manual)3.42 3,500 lbs. (1 588 kg)
3.73 4,000 lbs. (1 814 kg)
4800 V8 (Auto) 3.73 6,500 lbs. (2 948 kg)
4.10 7,500 lbs. (3 402 kg)
4800 V8 (Manual)3.73 4,500 lbs. (2 041 kg)
4.10 5,500 lbs. (2 495 kg)
5300 V8 3.73 7,500 lbs. (3 402 kg)
4.10 8,000 lbs. (3 629 kg)
* Weight distributing hitch tongue weight 10% to
15% of hitch pulling weight 1,000 lb. (454 kg)
maximum. Fifth
-wheel hitch tongue weight 15% to
25% of hitch pulling weight 1,500 lb (680 kg) maximum.C
-2500 LD (2WD)*
Engine Axle
RatioMax. Trailer Wt.
5300 V8 3.42 6,500 lbs. (2 948 kg)
3.73 7,500 lbs. (3 402 kg)
4.10 8,500 lbs. (3 856 kg)
6000 V8 3.42 7,500 lbs. (3 402 kg)
3.73 8,500 lbs. (3 856 kg)
4.10 10,500 lbs. (4 763 kg)
6.5 L Diesel 3.42 7,500 lbs. (3 402 kg)
* Weight distributing hitch tongue weight 10% to
15% of hitch pulling weight 1,200 lb. (544 kg)
maximum. Fifth
-wheel hitch tongue weight 15% to
25% of hitch pulling weight 2,000 lb (907 kg) maximum.

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4-58
C-2500 HD (2WD)*
Engine Axle
RatioMax. Trailer Wt.
6000 V8 3.42 7,500 lbs. (3 402 kg)
3.73 8,500 lbs. (3 856 kg)
4.10 10,500 lbs. (4 763 kg)
6.5 L Diesel 3.42 11,000 lbs. (4 990 kg)
4.10 11,000 lbs. (4 990 kg)
* Weight distributing hitch tongue weight 10% to
15% of hitch weight 1,200 lb. (544 kg) maximum.
Fifth
-wheel hitch tongue weight 15% to 25% of hitch
weight 2,500 lb (1 134 kg) maximum.K
-2500 HD (4WD)*
Engine Axle
RatioMax. Trailer Wt.
6000 V8 3.73 8,000 lbs. (3 629 kg)
4.10 10,000 lbs. (4 536 kg)
6.5 L Diesel 3.42 10,500 lbs. (4 763 kg)
4.10 10,500 lbs. (4 763 kg)
* Weight distributing hitch tongue weight 10% to
15% of hitch weight 1,200 lb. (544 kg) maximum.
Fifth
-wheel hitch tongue weight 15% to 25% of hitch
weight 2,500 lb (1 134 kg) maximum.
You can ask your dealer for our trailering information or
advice, or you can write us at the address listed in your
Warranty and Owner Assistance Information Booklet.
In Canada, write to:
General Motors of Canada Limited
Customer Communication Centre
1908 Colonel Sam Drive
Oshawa, Ontario L1H 8P7

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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, see ªEngine
Overheatingº in the Index.
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 for an automatic transmission, or into
gear for a manual transmission.
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 shift into PARK (P) for an
automatic transmission, or REVERSE (R) for a
manual transmission.
5. If you have a four
-wheel-drive vehicle, be sure
the transfer case is in a drive gear and not in
NEUTRAL (N).
6. Release the regular brakes.

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4-64
CAUTION:
It can be dangerous to get out of your vehicle if
the shift lever is not fully in PARK (P) with the
parking brake firmly set. Your vehicle can roll.
If you have left the engine running, the vehicle
can move suddenly. You or others could be
injured. To be sure your vehicle won't move, even
when you're on fairly level ground, use the steps
that follow.
Always put the shift lever fully in PARK (P) with
the parking brake firmly set.
If the transfer case on four-wheel drive vehicles is
in NEUTRAL (N), your vehicle will be free to
roll, even if your shift lever is in PARK (P). So, be
sure the transfer case is in a drive gear
-- not in
NEUTRAL (N).
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.
Maintenance When Trailer Towing
Your vehicle will need service more often when you're
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission fluid (don't
overfill), engine oil, axle lubricant, belt, cooling system
and brake system. Each of these is covered in this
manual, and the Index will help you find 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.

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4-65 Trailer Wiring Harness
Your vehicle is equipped with one of the following
wiring harnesses for towing a trailer or hauling a
slide
-in camper.
Basic Trailer Wiring Package
All regular and extended cab gasoline engine pickups
have a six
-wire trailer towing harness.
The six-wire harness is located at the rear of the vehicle
and is tied to the vehicle's frame. The harness requires
the installation of a trailer
-wiring harness connector,
which is available through your dealer.
The six
-wire harness contains the following
trailer circuits:

Yellow: Left Stop/Turn Signal

Dark Green: Right Stop/Turn Signal

Brown: Taillamps

White: Ground

Light Green: Back
-up Lamps

Light Blue: Center High
-Mounted
Stoplamp (CHMSL)
If you need to upgrade your vehicle to heavy
-duty
trailering, a brake controller harness and an underbody
harness with a seven
-pin universal heavy-duty trailer
connector are available from your dealer.

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Basic Trailer Wiring Package (Diesel Engine)
Regular and extended cab pickups equipped with a
6.5L Turbo Diesel engine have an eight
-wire trailer
towing harness.
The trailer wiring harness with a seven-pin connector
and separate Center High
-Mounted Stoplamp (CHMSL)
connector are located at the rear of the vehicle and are
tied to the vehicle's frame.* The harness connector can
be plugged into a seven
-pin universal heavy-duty trailer
connector available through your GM dealer.* The single CHMSL wire is tied to the seven
-wire
harness and is used if your trailer or cap are equipped
with a CHMSL.
The eight
-wire harness contains the following
trailer circuits:

Yellow: Left Stop/Turn Signal

Dark Green: Right Stop/Turn Signal

Brown: Taillamps

White: Ground

Light Green: Back
-up Lamps

Light Blue: CHMSL

Red: Battery Feed

Dark Blue: Trailer Brake
If you need to upgrade your vehicle to heavy
-duty
trailering, a brake controller harness and a seven
-pin
universal heavy
-duty trailer connector are available
from your GM dealer.

5-
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Section 5 Problems on the Road
Here you'll find what to do about some problems that can occur on the road.
5
-2 Hazard Warning Flashers
5
-3 Other Warning Devices
5
-3 Jump Starting
5
-8 Towing Your Vehicle
5
-9 Engine Overheating (Gasoline Engine)5
-12 Cooling System (Gasoline Engine)
5
-18 Engine Fan Noise
5
-18 If a Tire Goes Flat
5
-18 Changing a Flat Tire
5
-33 If You're Stuck: In Sand, Mud, Ice or Snow