transfer case GMC YUKON 1999 Owner's Guide

Long Trip/Highway Scheduled Maintenance
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The services shown in this schedule up to 100,000 miles
(166 000 km) should be performed after 100,000 miles
(166 000 km) at the same intervals. The services shown
at 150,000 miles (240 000 km) should be performed at
the same interval after 150,000 miles (240 000 km).
See ªOwner Checks and Servicesº and ªPeriodic
Maintenance Inspectionsº following.
Footnotes
 The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to the
completion of the vehicle's useful life. We, however,
urge that all recommended maintenance services be
performed at the indicated intervals and the maintenance
be recorded.# Lubricate the front suspension, kingpin bushings,
steering linkage, transmission shift linkage, transfer case
shift linkage, parking brake cable guides, front axle
propshaft spline and brake pedal springs. Ball joints and
kingpin bushings should not be lubricated unless their
temperature is 10F (
-12C) or higher, or they
could be damaged.
+ A good time to check your brakes is during tire
rotation. See ªBrake System Inspectionº under ªPeriodic
Maintenance Inspectionsº in Part C of this schedule.
** Drive axle service (see ªRecommended Fluids and
Lubricantsº in the Index for proper lubricant to use):

Locking Differential
-- Drain fluid and refill at first
engine oil change. At subsequent oil changes, check
fluid level and add fluid as needed.

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7-40 Drive Axle Service
Check rear/front axle fluid level and add as needed.
Check constant velocity joints and axle seals for leaking.
Transfer Case (Four-Wheel Drive)
Inspection
Every 12 months or at oil change intervals, check front
axle and transfer case and add lubricant when necessary.
Check vent hose at transfer case for kinks and proper
installation. More frequent lubrication may be required
on off
-road use.
Brake System Inspection
Inspect the complete system. Inspect brake lines and
hoses for proper hook
-up, binding, leaks, cracks,
chafing, etc. Inspect disc brake pads for wear and rotors
for surface condition. Also inspect drum brake linings
for wear and cracks. Inspect other brake parts, including
drums, wheel cylinders, calipers, parking brake, etc.
Check parking brake adjustment. You may need to have
your brakes inspected more often if your driving habits
or conditions result in frequent braking.

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USAGEFLUID/LUBRICANT
Front AxleSAE 80W-90 Axle Lubricant (GM
Part No. 1052271 or equivalent).
Rear Axle
(Locking
Differential)SAE 80W-90 Axle Lubricant;
use only GM Part No. 1052271.
Do not add friction modifier.
Automatic
Transfer CaseAutomatic Transfer Case Fluid
(GM Part No. 12378396).
Front Axle
Propshaft Spline
and Universal
JointsChassis Lubricant (GM Part
No. 12377985 or equivalent) or
lubricant meeting requirements of
NLGI # 2, Category LB
or GC
-LB.
Hood Latch
Assembly,
Secondary Latch,
Pivots, Spring
Anchor and
Release PawlLubriplate
Lubricant Aerosol
(GM Part No. 12346293 or
equivalent) or lubricant meeting
requirements of NLGI # 2,
Category LB or GC
-LB.
USAGEFLUID/LUBRICANT
Hood and Door
HingesMulti-Purpose Lubricant,
Superlube
(GM Part
No. 12346241 or equivalent).
Body Door
Hinge Pins,
Tailgate Hinge
and Linkage,
Folding Seat and
Fuel Door HingeMulti-Purpose Lubricant,
Superlube
(GM Part
No. 12346241 or equivalent).
Outer Tailgate
Handle Pivot
PointsMulti-Purpose Lubricant,
Superlube
(GM Part
No. 12346241 or equivalent).
Weatherstrip
ConditioningDielectric Silicone Grease (GM
Part No. 12345579 or equivalent).
Weatherstrip
SqueaksSynthetic Grease with Teflon,
Superlube
(GM Part
No. 12371287 or equivalent).

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CURRENT PUBLICATIONS FOR 1999 GMC
SERVICE MANUALS
Service Manuals have the diagnosis and repair information
on engines, transmission, axle, suspension, brakes,
electrical, steering, body, etc.
RETAIL SELL PRICE: $90.00
TRANSMISSION, TRANSAXLE, TRANSFER CASE
UNIT REPAIR MANUAL
This manual provides information on unit repair service
procedures, adjustments and specifications for the
1999 GM transmissions, transaxles and transfer cases.
RETAIL SELL PRICE: $50.00
SERVICE BULLETINS
Service Bulletins give technical service information needed
to knowledgeably service General Motors cars and trucks.
Each bulletin contains instructions to assist in the
diagnosis and service of your vehicle.OWNER'S INFORMATION
Owner publications are written directly for Owners and
intended to provide basic operational information about the
vehicle. The owner's manual will include the Maintenance
Schedule for all models.
In-Portfolio: Includes a Portfolio, Owner's Manual and
Warranty Booklet.
RETAIL SELL PRICE: $15.00
Without Portfolio: Owner's Manual only.
RETAIL SELL PRICE: $10.00
CURRENT & PAST MODEL ORDER FORMS
Service Publications are available for current and past
model GM vehicles. To request an order form, please
specify year and model name of the vehicle.
PLEASE COMPLETE THE ORDER FORM SHOWN ON
THE FOLLOWING PAGE AND MAIL TO:
Helm, Incorporated
P.O. Box 07130
Detroit, MI 48207OR ORDER TOLL FREE: 1-800-551-4123
Monday-Friday 8:00 AM ± 6:00 PM Eastern Time
For Credit Card Orders Only (VISA±MasterCard±Discover)
1999 GMC SERVICE PUBLICATIONS ORDERING INFORMATION
The following publications covering the operation and servicing of your vehicle can be purchased by filling out
the Service Publication Order Form in this book and mailing it in with your check, money order,
or credit card information to Helm, Incorporated (address below.)

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9-5
Gages
Engine Coolant Temperature 2-76 . . . . . . . . . . . . . . . . . . . .
Engine Oil Pressure 2-79 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel 2-82 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Speedometer 2-71 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tachometer 2-71 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltmeter 2-74 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GAWR 4-44 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gear Positions, Automatic Transmission 2-25 . . . . . . . . . . . . .
Glove Box 2-55 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GM Mobility Program for Persons with Disabilities 8-5 . . . . .
GM Vehicle Care/Appearance Materials 6-54 . . . . . . . . . . . . .
Gross Axle Weight Rating 4-44 . . . . . . . . . . . . . . . . . . . . . . . .
Gross Vehicle Weight Rating 4-43 . . . . . . . . . . . . . . . . . . . . . .
Guide en Fran†ais ii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GVWR 4
-43 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Halogen Bulbs 6-34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hazard Warning Flashers 5-2 . . . . . . . . . . . . . . . . . . . . . . . . . .
Head Restraints 1-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Headlamp Delay 2-48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Headlamps 2-46, 6-34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bulb Replacement 6-34, 6-61 . . . . . . . . . . . . . . . . . . . . . . .
High/Low Beam Changer 2-41 . . . . . . . . . . . . . . . . . . . . . .
On Reminder 2-47 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wiring 6-56 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hearing Impaired, Customer Assistance 8-4 . . . . . . . . . . . . . .
Heated Front Seats 1-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Heated Rear Seats 1-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Heating 3-2, 3-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
High-Beam Headlamps 2-41 . . . . . . . . . . . . . . . . . . . . . . . . . .
Highway Hypnosis 4-36 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hill and Mountain Roads 4-36 . . . . . . . . . . . . . . . . . . . . . . . . .
Hitches, Trailer 4-48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hood, Checking Things Under 6
-8 . . . . . . . . . . . . . . . . . . . . .
Hood Release 6-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Horn 2-39 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hydroplaning 4-32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ignition Positions 2-21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ignition Transmission Lock Check 7-38 . . . . . . . . . . . . . . . . .
Inflation, Tire 6-40 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inside Rearview Mirror 2-51 . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspections 7-39 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake System 7-40 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Drive Axle 7-40 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Cooling System 7-39 . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust System 7-39 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steering 7-39 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Suspension 7-39 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Throttle System 7-39 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transfer Case (Four-Wheel Drive) 7-40 . . . . . . . . . . . . . . .
Instrument Panel 2-68 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brightness Control 2-49 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning 6-49 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cluster 2-70 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuse Block 6-57 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interior Lamps 2-49 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Jack, Tire 5-20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Jump Starting 5-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Key Lock Cylinder Service 7-36 . . . . . . . . . . . . . . . . . . . . . .
Keyless Entry System 2-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Keys 2-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Tire-Loading Information Label 4-43 . . . . . . . . . . . . . . . . . . .
Tires 6-39 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Alignment and Balance 6-45 . . . . . . . . . . . . . . . . . . . . . . . .
Buying New 6-43 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chains 6-46 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing a Flat 5-19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning 6-52 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inflation 6-40 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inflation Check 7-35 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Rotation 6-41 . . . . . . . . . . . . . . . . . . . . . . . .
Loading 4-43 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure 6-40 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Temperature 6-44 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Traction 6-44 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Treadwear 6-44 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Uniform Quality Grading 6-44 . . . . . . . . . . . . . . . . . . . . . . .
Used Wheel Replacement 6-46 . . . . . . . . . . . . . . . . . . . . . .
Wear Indicators 6-42 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wheel Replacement 6-45 . . . . . . . . . . . . . . . . . . . . . . . . . . .
When It's Time for New 6-42 . . . . . . . . . . . . . . . . . . . . . . .
Top Strap 1-46 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Torque Lock 2-35 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Torque, Wheel Nut 5-29, 6-63 . . . . . . . . . . . . . . . . . . . . . . . . .
Towing
From the Front 5
-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
From the Rear 5-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recreational Vehicle 4-42 . . . . . . . . . . . . . . . . . . . . . . . . . .
Trailer 4-45 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Your Vehicle 5-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Trailer
Brakes 4
-49 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Driving on Grades 4-51 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Driving with 4-49 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Cooling When Towing 4-53 . . . . . . . . . . . . . . . . . . .
Hitches 4-48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance When Towing 4-53 . . . . . . . . . . . . . . . . . . . . .
Parking on Hills 4-52 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Safety Chains 4-48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tongue Weight 4-47 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Total Weight on Tires 4-48 . . . . . . . . . . . . . . . . . . . . . . . . . .
Towing 4-45 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Turn Signals 4-51 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Weight 4-46 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wiring Harness 4-53 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transfer Case 6-21, 7-41 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transfer Case, Automatic 2-28 . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission Fluid, Automatic 6-17, 7-41 . . . . . . . . . . . . . . .
Transmitter, Keyless Entry 2-6 . . . . . . . . . . . . . . . . . . . . . . . . .
Transmitter, Universal 2-63 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transportation, Courtesy 8-8 . . . . . . . . . . . . . . . . . . . . . . . . . .
Trip Odometer 2-71 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TTY Users 8-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Turn Signal and Lane Change Signals 2-40 . . . . . . . . . . . . . . .
Turn Signals When Towing a Trailer 4-51 . . . . . . . . . . . . . . . .
Underbody Maintenance 6-53 . . . . . . . . . . . . . . . . . . . . . . . .
Underhood Fuse/Relay Center 6-59 . . . . . . . . . . . . . . . . . . . . .
Universal Transmitter 2-63 . . . . . . . . . . . . . . . . . . . . . . . . . . . .