change time GMC C-SERIES 1999 User Guide

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6-20
Rear Axle
When to Check and Change Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant and when to change it.
See ªScheduled Maintenance Servicesº in the
Maintenance Schedule.
How to Check Lubricant
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 ªRecommended Fluids and
Lubricantsº in the Maintenance Schedule.
Rear Axle Shift Motor (Option)
When to Check and Change Fluid
If you have an optional air-shift two-speed, controlled
traction, or locking differential type rear axle, a good
time to check the fluid level in the axle shift motor is
when the rear axle lubricant is checked. Use refrigerant
oil (shift motor only).
How to Check Fluid
Remove the plug on the front plate of the axle shift
motor, add enough fluid to raise the level to the bottom
of the filler plug hole, then replace the plug.
What to Use
Refer to your Maintenance Schedule to determine what
kind of lubricant to use.
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6-57
CAUTION:
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 wheel could come off and
cause an accident. When you change a wheel,
remove any rust or dirt from the places where the
wheel attaches to the vehicle. In an emergency,
you can use a cloth or paper towel to do this; but
be sure to use a scraper or wire brush later, if you
need to, to get all the rust or dirt off.
How Often to Check
Wheel tightness is so important you should have a
technician check nut tightness on all wheels with a
torque wrench every 1,000 miles (1 600 km).
When your vehicle is new or when a wheel or fastener is
new you should have a technician tighten the wheel
stud and rim clamp nuts, with a torque wrench, at
100, 500 and 1,000 miles (160, 800 and 1 600 km).
The reason for this is that the clamping system has to
seat before the fasteners will stay tightened.
Wheel Replacement
Replace any wheel that is bent, cracked or badly rusted.
If wheel nuts keep coming loose, replace the wheel.
If the wheel leaks air, replace it.
Your dealer will know the kind of wheel you need.
CAUTION:
A leaking wheel could fail without warning. A
wheel designed for tubeless tires could be leaking
because it is damaged. Don't use an inner tube or
some other thing to try to stop the leaking. Get a
new wheel of the proper type.
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6-74
Replacement Bulbs
It is recommended that you use an AC
type bulb
whenever you need to replace one.
Before you replace any bulbs, be sure that all lamps are
off and the engine isn't running.
Capacities and Specifications
Replacement part numbers listed in this section are
based on the latest information available at the time of
printing. They are subject to later change. If a part listed
here isn't the same as the part in your vehicle when it
was built, or if you have any questions, please contact
your GM Truck dealer.
Engine Identification and Data
Engine RPO LG5 LP4/L21
Engine Type 7.2L L6 7.4L V8
Fuel System HEUI SPFI
Firing Order
1
-5-3-6-2-41-8-4-3-6-5-7-2
Wheel Nut Torque
Refer to ªTightening the Wheel Nutsº in this section for
wheel nut torque information.
Cooling System Capacity
Model Quarts (Liters)
7.2L 32.0 (30.0). . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
with automatic transmission 30.0 (28.4). . . . . . . . . .
7.4L 25.0 (23.7). . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
with automatic transmission 23.0 (22.7). . . . . . . . . .
Above capacities (volumes) are approximate.
Crankcase Capacity
Capacities (volumes) shown are for normal refill. Add
oil as indicated when the oil filter element is changed.
Capacities given are approximate
-- keep level within
the operating range. Do not operate with fluid level
below the ADD line.
Engine
Capacity
-- Quarts (Liters)
7.2L 21 (19.0)*
7.4L 8 (7.5)
*Additional oil is required with auxiliary oil filter
systems. Make sure to add enough extra oil to fill the
auxiliary oil filter system. For vehicles equipped with
the LUBERFINER 750
-C, add 14 quarts (13.25 L).
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8-9
PUBLICATION FORM
NUMBEROrders will be mailed within 10 days of receipt. Please allow adequate time for postal
service. If further information is needed, write to the address shown below or call
1-800-551-4123. Material cannot be returned for credit without packing slip with return
information within 30 days of delivery. On returns, a re-stocking fee may be applied
against the original order. ORDER TOLL FREE
(NOTE: For Credit Card Holders Only)1-800-551-4123(Monday-Friday 8:00 AM ± 6:00 PM EST)
FAX Orders Only 1-313-865-5927
Service Manual
NOTE: Dealers and Companies please provide dealer or company name, and also the
name of the person to whose attention the shipment should be sent.
Mail completed order form to:
HELM, INCORPORATED
P.O. Box 07130
Detroit, MI 48207
For purchases outside U.S.A. please write to the above address for quotation.
1999$90.00
1999
$50.00
1999
$15.00
1999
$10.00
TOTAL MATERIAL
Michigan Purchasers
U.S. Order Processing$5.00
Canadian Postage
GRAND TOTAL
add 6% sales tax
(See Note Below)
GM-GMC-ORD99 *(Prices are subject to change without notice and without incurring
obligation. Allow ample time for delivery.)Note to Canadian Customers: All listed prices are quoted in U.S. funds. Canadian residents
are to make checks payable in U.S. funds. To cover Canadian postage, add $11.50 plus the
U.S. order processing.
(CUSTOMER'S NAME) (ATTENTION)
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AREA CODE
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Order payable to
Helm, Inc. (USA funds
only Ð
do not send cash.)
VISA
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Account
Number:
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CUSTOMER SIGNATURE
S
ITEM DESCRIPTIONNAME YEAR VEHICLE MODEL
QTY.PRICE
EACH*TOTAL
PRICE1
9
9
9
G
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9-9
Storage, Vehicle 6-42 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stuck: In Sand, Mud, Ice or Snow 5-37 . . . . . . . . . . . . . . . . . .
Sun Visors 2-48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Surge Tank, Coolant 5-29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Surge Tank Pressure Cap 6-22 . . . . . . . . . . . . . . . . . . . . . . . . .
Symbols, Vehicle v. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tape Player Care 3-12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Theft 2-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermostat 6-22 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tilt Steering Wheel 2-31 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tire Loading 6-48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tires 6-48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing a Flat 5-34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning 6-64 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dual Tire Operation 6-50 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inflation 6-49 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inflation Check 7-23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loading 6-48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure 6-49 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rims and Wheels 6-50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wheel Replacement 6-57 . . . . . . . . . . . . . . . . . . . . . . . . . . .
When It's Time for New 6-51 . . . . . . . . . . . . . . . . . . . . . . .
Top Strap 1-30 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Torque, Wheel Nut 6-52 , 6-74 . . . . . . . . . . . . . . . . . . . . . . . .
Towing Your Vehicle 5-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Trailer Brake Hand Control Valve 2
-39 . . . . . . . . . . . . . . . . . .
Trailer Connections 2-49 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission
Automatic 2
-20, 6-18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Automatic Transmission External Filter 6-19 . . . . . . . . . . .
Double-Clutching 2-22 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Filters 6-77 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid, Automatic 6-18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Capacity 6-75 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual 2-22, 6-19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual, Fluid 6-19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Third Gear Hold 2-21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using the Clutch 2-22 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Automatic 6-18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual 6-19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TTY Users 8-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Turn and Lane Change Indicator 2-33 . . . . . . . . . . . . . . . . . . .
Underbody Maintenance 6-65 . . . . . . . . . . . . . . . . . . . . . . . .
Vehicle
Control 4-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Damage Warnings iv. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Identification Number 6
-67 . . . . . . . . . . . . . . . . . . . . . . . . .
Loading 4-28 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage 6-42 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ventilation System 3-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Visors, Sun 2-48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltmeter 2-56 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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