1993 GMC SIERRA Section 7

AM480043
Run your engine only as long as you musk. This saves fuel. When you run
the engine, make it go a little faster than just idle. That is, push the
accelerator slightly. This uses less fuel for the heat that yo\
u get and
it keeps
the battery (or batteries) charged. You will need a well-charged battery (or
batteries) to restart the' vehicle, and possibly for signaling later on with your
headlights. Let the heater run for awhile.
If you 'have a diesel engine, you
may have to run it at a higher speed
to lget enough heat. Then, shut the
engine
off and close the window almost all the way to preserve the heat.
Start the engine again and repeat this only when you feel really
uncomfortable from the cold. But
do it as little as'possible. Preserve the fuel
as long as you can.
To help keep warm, you can get out of the vehicle and
do some fairly vigorous exercises every half hour or so until help comes.
If You're Stuck in Deep Snow
This manual explains how to get the vehicle out of deep snow without
damaging it. See "Rocking Your Vehicle" in the Index.
Towing a mailer
CAUTION I
If you don't use the correct equipment and drive properly, you ca\
n
lose control when you pull a trailer. For example, if the trailer is too
heavy, the brakes may not work well-or even at all. You and your
passengers could be seriously injured. Pull a trailer only if \
you have
followed all the steps in this section.
I
i'- ." "
4-55
ProCarManuals.com

z
Your Driving and the Road
NOTICF
Pulling a trailer improperly can damage your vehicle and result in costly
repairs
not covered by your warranty. To pull a trailer correctly, follow the
advice in this section.
Every vehicle
is ready for some trailer. towing. If it 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 chan\
ges isn handling,
durability, and fuel .economy. Successful, safe trailering .takes\
correct
equipment, and
it has to be used properly.
That’s the reason for this section. 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. .
0 There are many different laws 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 4,000 pounds
(1 800 kg) or less. You should always use a sway control if your trailer
will weigh more than 4,000 pounds (1800 kg). 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/ti) and don’t make ,starts at full throttle. T\
hat
will help your engine and other parts of your vehicle wear in at the
heavier load$.
Three important considerations have to do with weight:
Weight
Weight of the Trailer
How heavy can a trailer safely be?
It should never be more than 13,500 Ibs. (6125.6 kg). But even \
that can be
too heavy. It depends on how you plan to use your rig. For example, speed,
altitude, ‘road grades, outside temperature, and how much your vehicle is
4-56
ProCarManuals.com

CAUTION
It can be dangerous to get out of your vehicle if the shift lever is not
fully in
P (Park) with the parking brake firmly set. Your vehicle can
roll.
If you have left the engine running, the vehicle can move suddenl\
y.
You
or others could be injured. To be sure your vehicle won’t move,
when you’re on fairly level ground, use the steps that follow.
If you have four-wheel drive and your transfer case is in N (Neutral),
your vehicle will be free to
roll, even if your shift lever is in P (Park).
So, be sure the transfer case is in a drive gear-not in N (Neutral).
If you are parking on a hill, or if you’re pulling a trailer, also see
“Parking On Hills” in the Index.
When You Are Ready to Leave After Parklng 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 To wing
Your vehicle will need service more often when you’re pulling a trailer. See
the Maintenance Schedule for more on this. Things that are esp\
ecially
important in trailer operation are automatic transmission fluid (don’t overfill),
engine oil, axle lubricant, belts, cooling system, and brake ad\
justment. 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.
mailer Wiring Harness
See “Trailer Wiring Harness’’ in the Index.
4-61
ProCarManuals.com

Pmb/ems on the Road
1 Section
Here you’ll find what to do about some problems that can occur on the road .
Hazard Warning Flasher ........................................................................\
............... 5-2
Other Warning Devices ........................................................................\
................. 5-3
Jump Starting ........................................................................\
................................ 5-3
Towing Your Vehicle ........................................................................\
...................... 5-8
Engine Overheating ........................................................................\
....................... 5-9
If
If
a Tire Goes Flat ........................................................................\
...................... 5-17
Changing a Flat Tire
........................................................................\
............... 5-17
Jack Storage
........................................................................\
............................ 5-19
Spare Tire
........................................................................\
................................ 5-20
You’re Stuck: In Sand. Mud. Ice or Snow ................................................... 5-33
5-1
ProCarManuals.com

Service & Appearance Care
.....
Here you will find information about the care of your vehicle . This Section
begins with service and fuel information. and then it shows how to check
important fluid and lubricant levels
. There is also technical information about
your vehicle. and a section devoted to its appearance care
.
Service ........................................................................\
........................................... 6-3
Fuel (Gasoline Engines)
........................................................................\
............... 6-4
Diesel Fuel Requirements and Fuel System
...................................................... 6-6
Checking Things Under the Hood
..................................................................... 6-17
Hood Release
........................................................................\
.......................... 6-18
Cleaning Your Diesel Engine
........................................................................\
.. 6-19
Noise Control System
........................................................................\
............. 6-19
Engine Oil (Except Diesel)
........................................................................\
..... 6.20
Engine Oil (Diesel Engines)
........................................................................\
... 6-26
Air Cleaner
........................................................................\
............................... 6-31
Automatic Transmission Fluid
........................................................................\
. 6-33
Manual Transmission Fluid
........................................................................\
..... 6-36
Hydraulic Clutch
........................................................................\
....................... 6-37
Transfer Case
........................................................................\
.......................... 6-39
Front Axle ........................................................................\
................................. 6-40
Rear Axle
........................................................................\
................................. 6-41
6-1
ProCarManuals.com

Service & Appearance Care
1 If you try to do your own service work without knowing enough ab\
out it, I
1 your vehicle could be damaged.
Maintenance Schedule
Section 7 of this manual, “Scheduled Maintenance Services”, explains the \
maintenance your new vehicle needs, and when
it -should be done. It also,
has a form that you can use to record the maintenance work done \
on your
vehicle. Be sure to read this ,information.
-I .. >. ’ , .
Fuel (Gasoline Engines)
If your vehicle has a diesel engine, see “Diesel Fuel Requi\
rements and Fuel
System’’ in this Section: For vehicles with gasoline engines, please read this.
Use regular unleaded gasoline rated at 87 octane or’higher.
It should meet
specifications ASTM D4814 in the
U.S. and CGSB 3.592 in Canada. These
fuels should have the proper additives,
so you should not have to add
anything to the fuel.
In the
U.S. and Canada, it’s easy to be sure you get the right kind of
gasoline (unleaded). You’ll see
UNLEADED right on the pump. And only
unleaded nozzles
will fit into your vehicle’s filler neck.
Be sure the posted octane is at least 87. If the octane
is less than 87, you
may get a heavy knocking noise when you drive.
If it’s bad enough, it can
damage your engine.
6-4
ProCarManuals.com

Service & Appearance Care
Diesel Fuel Requirements
and Fuel System
Some states and provinces have restrictions on the purchase of diesel fuel
for light-duty vehicles and require you
to buy permits or pay special taxes.
Some of these restrictions apply only
to residents, and others apply to both
residents and visitors. These restrictions can change.
To learn the current
restrictions in any state or province, contact your auto club, \
the police or
other officials.
Fuel Requirements
1 NOTICE
Diesel fuel or fuel additives not recommended in this manual could
damage your fuel system and engine. Your warranty wouldn’t cover thi
damage. And:
Diesel fuel that has been mixed with engine oil could damage your
engine and emission controls.
Always check with your service station
his
diesel fuel, it can be difficult to restart your
engine. “Running Out of Fuel,” later
in this section, tells you how to
get
it started again. To avoid all this, try never to let. your tank get
What Fuel to Use:
You can use either Number I-D or Number 2-D diesel fuel, but you’ll get
better fuel economy using
2-D.
Diesel fuel may foam when you fill your tank. This can cause the automatic
pump nozzle
to shut off, even though your tank isn’t full. If this happens, just
wait for the foaming to stop and then continue to fill your tank.
1 CAUTION
- Heat coming from the engine may cause the fuel to expand and force
the fuel out of your tank. If something ignites the fuel, a \
fire could start
and people could be burned.
To help avoid this, fill your fuel tank only
until the automatic nozzle shuts
off. Don’t try to “top if off .” I
I
6-6
ProCarManuals.com

Hydraulic Clutch Grease Fitting
A grease fitting is on the clutch housing for lubricating the clutch fork ball
stud. See your Maintenance Schedule for when to lubricate the clutch
housing. See “Recommended Fluids and Lubricants” in the Index for the
proper lubricant to use.
Be sure not to over-fill because you could damage your clutch.
Four- Wheel Drive
Most lubricant checks in this section also apply to four-wheel-drive vehicles.
However, they have 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. See “Periodic Maintenance Inspections” in the Index.
How to Check and Add Lubricant:
I
PO230
If the level is below the bottom of the filler plug hole, you’ll need to add
some lubricant. Add enough lubricant to raise the level to the bottom of the
filler plug hole.
What to Use:
Refer to the Maintenance Schedule to determine what kind of lubricant to
use. See “Recommended Fluids and Lubricants” in the Index.
639
ProCarManuals.com