1993 GMC SIERRA torque

D (Third Gear)
This is like
OD, but you never go into Overdrive. You should use D when
towing a trailer, carrying a heavy load, driving on steep hills, or for off-road
driving.
2 (Second Gear)
This position gives you more power but lower fuel economy. You can use
2
on hills. It can help control your speed as you go down steep mountain
roads, but then you would also want to use your brakes
off and on.
If you manually select 2, the transmission will drive in second gear. You may
use this feature for reducing torque to the rear wheels when you are trying
to
start your vehicle from a stop on slippery road surfaces.
1 (First Gear)
This position gives you even more power (but lower fuel econo\
my) than
2.
You can use it on very steep hills, or in deep snow or mud. If the selector
lever
is put in 1, the transmission won’t shift into first gear until the vehic\
le is
going slowly enough.
NWTIGE
If your rear wheels can’t rotate, don’t try to drive. This might happen if
you were stuck in very deep sand or mud or were up against a. solid
object. You could damage your transmission.
AWZ , <,*,~l,<.,. ...
Also, if you stop when going uphill, don’t hold your vehic there with only the
accelerator pedal.
This could overheat and damage ,the transmission. Use your
brakes or shii into P (Park) to hdd your vehicle in position on a hill.
.,$*’,,&:&> ._,, , . ~ ~ ,>&:a
2-23
ProCarManuals.com

Features & Controls
Propshaft Brake Burnish Procedure
If you have a 3500 HD Model, it is recommended that the propshaft mounted
parking brake be burnished as part of the new vehicle break in. The parking
brake
will work best after it has been burnished following these instructions.
Make
10 stops, using the parking brake foot pedal, from 20 mph (32 k\
m/h)
about 2
112 miles (4 km) apart. In between stops, drive the vehicle at 20
mph (32 kmlh).
Torque Lock
The parking brake should be set first whenever leaving the dri\
ver’s seat. If
you are parked on a hill and the transmission is placed in P (Park) before
the parking brake is set, the weight of the vehicle may put too much force
on the parking pawl in the transmission.
It may be difficult to pull the selector
lever out of
P (Park). This is called “torque lock.” To prevent this, the parking
brake should be set
BEFORE moving the selector lever to P (Park).
When preparing
to move the vehicle, the selector lever should be moved out
of
P (Park) BEFORE releasing the parking brake. Set the parking brake first,
then release the transmission from
P (Park), even on level surfaces.
If “torque lock” does occur, you may have to have another vehicle nudge
your vehicle uphill a little
to take some of the pressure off the transmission
while you pull the selector lever out of
P (Park).
Shifting Into P (Park) (Automatic Transmission Models Only)
1 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 suddenly.
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 N
(Neutral).
If you are parking on a hill, or if you’re pulling a trailer, also see
“Parking on Hills9’ or “Towing a Trailer” in the Index. I
2-30
ProCarManuals.com

AM470053
If there is no curb when you’re parking uphill, turn the wheels to the right.
If there is no curb when you’re parking uphill on the left side of a one-way
street, your wheels should be turned to the left.
Torque Lock (Automatic Transmission)
If you are parking on a hill and you don’t shift your tra\
nsmission into P
(Park) properly, the weight of the vehicle may put too much force on the
parking pawl in the transmission. You may find it difficult to pull the shift lever
out of
P (Park). This is called “torque lock.” To prevent torque lock, always
be sure to shift into
P (Park) before you leave the driver’s seat. To find out
how, see “Shifting Into
P (Park)” in the Index.
When you are ready to drive, move the shift lever out
of P (Park) BEFORE
you release the parking brake.
If “torque lock” does occur, you may need to have another vehicle push
yours a little uphill to take some of the pressure from the transmission,
so
you can pull the shift lever out of P (Park).
4-5 1
ProCarManuals.com

Incorrect wheel nuts or improperly tightened wheel nuts can cau\
se
the wheel to become loose and even come
off. This could lead to
i accident. Be sure to use the correct wheel nuts. If you have to
Stop somewhere as soon as you can and have tht; wts tightened
vvith a torque wrench to the proper torque.
. lace them, be sure to get the right kind. mGe+ . p+p+<.:,
For proper torque, see “Wheel Nut Torque” in the Index.
Put the wheel trim back on. For vehicles with plastic nut cap\
s, tighten the
caps until they are finger tight, then tighten them an additio\
nal one-half turn
with the ratchet. Remove any wheel
blocks.
ring a jack, a tire or other equipment in the passenger - I.
compartment of the vehicle cnvld cause injuy In a sudden stnn OW 4s
in collision, loose equipment
the proper place.
-
Storing the Jack and Tire
Storing Tire in Underbody Carrier
UNDERBODY SPARE TIRE MOUNTING
HOIST
CABLE
RETAINER
& RATCHET
=r/49q “UP/DOWN” MARKING
WHEEL WRENCH

SHAFT (CHISEL END)
TIRE
a>
SPARE VALVE STEM
(POINTED DOWN)
PB009
Put the tire on the ground at the rear of the vehicle, with the valve stem
pointed down.
5-3 1
ProCarManuals.com

Other Maintenance Items
Front Suspension and Steering Linkage
Your maintenance schedule will tell you how often to lubricate the fittings. See
“Recommended Fluids and Lubricants’’ in the Index for the proper lubricant to
use.
Front Wheel Bearings
Your vehicle has front wheel bearings that must be cleaned and repa\
cked.
Your maintenance schedule will tell you how often this must be done.
Front Shock Absorbers
The front shock absorbers of your vehicle do many things. They help the
vehicle ride smoothly and also control the travel
of the suspension system.
When the shock absorbers are serviced, any replacement shock absorber\
s
must be the same as the original equipment shock absorbers in both
extended length and strength.
1 NOTICE
If you use shock absomers that are nor me same as the original shock
I absorbers, the shock absorbers or suspension system could be da\
maged.
Wheel Nut Torque
For vehicles with dual wheels, when the vehicle, wheel or fast\
eners are new,
have the torque set at the first
100, 1,000 and 6,000 miles (160, 1600 and
9600 km). Use the torque specified in the appropriate Specification \
Chart later
in this section.
Single Belt Accessory Drive
If your new vehicle uses a serpentine belt, it is lighter, and more durable
than systems with several belts.
The belt runs over or around the pulleys
on the engine. A tensioner is used
to keep the belt tight at all times. The tensioner also makes replacing the
belt easier.
If you need to replace the belt, be sure to get the correct
replacement belt. Your dealership
or parts supplier can help you with this.
The Accessory Drive Belt Routing label on your vehicle will sh\
ow you how to
route the belt your vehicle uses.
6-5 1
ProCarManuals.com

Service & Appearance Cam
Tire lnspecfion and Rotation
To make your tires last longer, have them inspected and rotated at the
mileages recommended in the Maintenance Schedule. See “Scheduled
Maintenance Services” in the Index.
Q
-
-
K2655
Use this rotation pattern.
If your vehicle has front tires with different load ratings or tread designs (such
as all season
vs. onloff road) than the rear tires, don’t rotate your tires \
front
to rear.
After the tires have been rotated, adjust the front and rear \
inflation pressure
as shown on the CertificationRire label. Make certain that all wheel nuts are
properly tightened. See “Wheel Nut Torque”
in the Index.
A Rust or dirt on a wheel, or on the parts to which -it is fastened, can
make the wheel nuts become loose after a time. The wh.eel could
come
off and cause an accident. When you change- a- :wheel, remove
’ any -rust or dirt from places where the wheel attaches to the vehicle:
,: In an emergency, you can use a cloth or paper towel to do this; but
3 be sure to use a scraper or wire brush later, if you need- to, to get
-T all the rust or dirf off. See “Changing a Flat Tire” in the Index.
6-78
ProCarManuals.com

Specification Charts
Replacement Parts
Replacement part numbers listed in this section are based on the latest
information available at the time of printing, and are subject \
to change. If a
part listed in this manual is not the same as the part used \
in your vehicle
when it was built, or
if you have any questions, please contact your GM truck
dealer.
Engine Identification
Liter Produced Fuel VIN
Displacement Type
U.S. TBI N
V8 7.4 H.D.
us. Diesel F V8 6.5
H.D. U.S. Diesel J V8 6.2
L. D. us. Diesel C V8 6.2
US., Can.
TBI K V8
5.7
L. D. US., Can.
TBI H
V8 5.0
U.S. TBI 2 V6
4.3
Emissions
BY
System
Engine Code
*
*
*
*Light Duty Emissions with 8500 GVWR and below or:
Heavy Duty Emissions with 8501 GVWR and above.
TO035
Wheel Nut Torque
MODEL I DESCRIPTION I TORQUE I
C 1500 5 bolts (14mm) 120 ft. Ibs. (160 Nmm)
K 1500 & C-K 2500 6 bolts f14mm) 120 ft. Ibs. (1 60 N.m)
C-K
2500 (w/C6P) 8 bolts (14mm) 120 ft. Ibs. (160 Nmm)
C-K 3500 Single Rear Wheels 8 bolts (14mm) 120
ft. Ibs.
(1 60 N-m)
C3500 Dual Rear Wheels
8 bolts (14mm) 140 ft. Ibs. (190
N-m)
C3500 HD -Front
5 bolts (5/8 in.) 175 ft. Ibs. (240 Nsm)
TO040
--Rear
10 bolts (5/8 in.)
6-95
ProCarManuals.com

23. EXHAUST PRESSURE REGULATOR VALVE INSPECTION* -Check that
the valve works properly. Correct any binding. Inspect hoses fo\
r cracks, chafing or decay. Replace parts as needed.
24.
TIRE AND WHEEL ROTATION AND INSPECTION -For proper wear
and maximum tire life, rotate tires at the first
6,000 miles (1 0 000
kilometers) for Schedule I (t) or 7,500 miles (12 500 kilometers) for
Schedule
II (.) and then every 15,000 miles (25 000 kilometers)
thereafter. Follow the instructions and patterns shown in Section 6.
Check tires for uneven wear or damage.
If irregular or premature wear is
apparent, check wheel alignment. Also, check for damaged wheels.\
See
“Tires” in the Index for more information.
For dual wheels, whenever the vehicle, wheels, or fasteners are new,
have the wheel fastener torque set at the first 100,
1,000 and 6,000
miles (160, 1600 and 10
000 km).
For 3500 H.D. Models, block the tires opposite those being removed to
keep the vehicle from rolling.
25.
DRIVE AXLE SERVICE -Check readfront axle fluid level and add as
needed. Check constant velocity joints and axle seals for leaki\
ng.
Locking differential-Drain fluid at first oil change and refill. Check
fluid level and add as needed at subsequent oil changes.
In dusty
areas, or trailer towing applications drain fluid at every 15,0\
00 miles
(24 135 kilometers) and refill$
every oil change. In dusty areas, or trailer towing applications, drain
fluid every 15,000 miles
(24 135 kilometers) and refi1l.t
More frequent lubrication may be required on heavy-duty or off-road
use.
Standard differential -Check fluid level and add as needed at
26.
BRAKE SYSTEM INSPECTION -When the engine oil is changed,
inspect the lines and hoses for proper hookup, binding, leaks, \
cracks,
chafing, etc. Check the parking brake adjustment, and the fluid level in
the master cylinder.
A low fluid level can indicate worn disc brake pads
which may need to be sewiced.t
*An Emission Control Service
tA fluid
loss in these systems may indicate a problem. Have them
inspected and repaired at once.
7-2
1
ProCarManuals.com