transfer case GMC SIERRA 2020 Owner's Guide

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Service and Maintenance 449
Footnotes—Maintenance
Schedule Additional Required
Services - Severe
(1) Or every two years, whichever
comes first. More frequent
replacement may be needed if the
vehicle is driven in areas with heavy
traffic, poor air quality, areas with
high dust levels or are sensitive to
environmental allergens. Filter
replacement may also be needed if
you notice reduced airflow, windows
fogging up, or odors. Your local GM
Service location can help you
determine when it is the right time to
replace your filter.
(2) Or every four years, whichever
comes first. If driving in dusty
conditions, inspect the filter at each
oil change or more often as needed.
See Engine Air Cleaner/Filter 0344.
(3) Visually check all fuel and vapor
lines and hoses for proper
attachment, connection, routing, and
condition.
(4) Do not directly power wash the
transfer case and/or front/rear axle
output seals. High pressure water can overcome the seals and
contaminate the fluid. Contaminated
fluid will decrease the life of the
transfer case and/or drive axles and
should be replaced.
(5)
Or every five years, whichever
comes first. See Cooling System
0 346.
(6) Or every 10 years, whichever
comes first. Inspect for fraying,
excessive cracking, or damage;
replace, if needed.
(7) Replace brake fluid every five
years. See Brake Fluid 0357.
(8) Or every 12 months, whichever
comes first. See Wiper Blade
Replacement 0364.
(9) Or every 10 years, whichever
comes first. See Gas Strut(s)0365.
(10) Replace air conditioning
desiccant every seven years.Special Application
Services
. Vehicles with Dual Wheels:
Check dual wheel nut torque at
160, 1 600, and 10 000 km (100,
1,000, and 6,000 mi) of driving.
Repeat this service whenever a
tire/wheel is serviced or
removed.
. Severe Commercial Use
Vehicles Only: Lubricate chassis
components every oil change.
. Have underbody flushing service
performed. See “Underbody
Maintenance” inExterior Care
0 429.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
454 Service and Maintenance
UsageFluid/Lubricant
Front Axle (Four-Wheel Drive) and Rear Axle See your dealer.
Hydraulic Brake System (Vehicles with DOT 3 brake fluid) DOT 3 Hydraulic Brake Fluid (GM Part No. 19353126, in
Canada 19353127). See
Brake Fluid0357.
Hydraulic Brake System (Vehicles with DOT 4 brake fluid) DOT 4 Hydraulic Brake Fluid (GM Part No. 19299570, in
Canada 19299571). See
Brake Fluid0357.
Hydraulic Power Steering System (2500/3500 Series Only) GM Power Steering Fluid (GM Part No. 19329450, in Canada 19329451).
Key Lock Cylinders, Hood Hinges, Body Door Hinge Pins, Tailgate
Hinge and Linkage, Fuel Door Hinge, Tailgate Handle Pivot Points, Hinges, Latch Bolt, and Linkage Multi-Purpose Lubricant, Superlube (GM Part No. 12346241, in
Canada 10953474).
Transfer Case (Four-Wheel Drive) DEXRON-VI Automatic Transmission Fluid. Weatherstrip Conditioning Weatherstrip Lubricant. See your dealer.Weatherstrip Squeaks Synthetic Grease with Teflon, Superlube (GM Part No. 12371287).
Windshield Washer Automotive windshield washer fluid that meets regional freeze protection requirements.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Technical Data 461
ApplicationCapacities
Metric English
3500 Series Chassis Cab –Rear Tank 151.4 L 40.0 gal
Transfer Case Fluid (1500 Series Only) 1.5 L 1.6 qt
Transfer Case Fluid (2500 and 3500 Series Only) 2.3 L 2.4 qt
Wheel Nut Torque 190 Y140 lb ft
All capacities are approximate. When adding, be sure to fill to the approximate level, as recommended in this
manual. Recheck fluid level after filling.
*Engine cooling system capacity values are based on the entire cooling system and its components.
Engine Specifications
Engine VIN CodeSpark Plug Gap
2.7L L4 (L3B) K0.65–0.75 mm (0.026–0.030 in)
4.3L V6 (LV3) H0.95–1.10 mm (0.037–0.043 in)
5.3L V8 (L82) F0.95–1.10 mm (0.037–0.043 in)
5.3L V8 (L84) D0.95–1.10 mm (0.037–0.043 in)
6.2L V8 (L87) L0.95–1.10 mm (0.037–0.043 in)
6.6L V8 (L8T) 70.95–1.10 mm (0.037–0.043 in)
Spark plug gaps are preset by the manufacturer. Re-gapping the spark plug is not recommended and can damage
the spark plug.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13337776) - 2020 - CRC - 4/4/19
492 Index
Extender, Seat Belt . . . . . . . . . . . . . . 71
Exterior Cargo Lamps . . . . . . . . . . 171
Exterior Lamp Controls . . . . . . . . . 165
Exterior Lamps Off Reminder . . . 167
Exterior Lighting BatterySaver . . . . . . . . . . . . . . . . . . . . . . . . . 174
F
FanEngine . . . . . . . . . . . . . . . . . . . . . . . . 353
Filter, Engine Air Cleaner . . . . . . . . . . . 344
Flash-to-Pass . . . . . . . . . . . . . . . . . . . 168
Flashers, Hazard Warning . . . . . . 169
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . 405 Changing . . . . . . . . . . . . . . . . . . . . . 407
FlexFuel
E85 . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
Floor Console Storage . . . . . . . . . . 115
Floor Mats . . . . . . . . . . . . . . . . . . . . . . 438
Fluid Automatic Transmission . . . . . . 343
Brakes . . . . . . . . . . . . . . . . . . . . . . . . 357
Four-Wheel DriveTransfer Case . . . . . . . . . . . . . . . 227
Power Steering . . . . . . . . . . . . . . . 354
Washer . . . . . . . . . . . . . . . . . . . . . . . 354
Fog Lamps . . . . . . . . . . . . . . . . . . . . . 170 Folding Mirrors . . . . . . . . . . . . . . . . . . 43
Forward Collision Alert
(FCA) System . . . . . . . . . . . . . . . . . 268
Four-Wheel Drive . . . . . . . . . . 227, 361
Four-Wheel-Drive Light . . . . . . . . . 142
Frequency Statement Radio . . . . . . . . . . . . . . . . . . . . . . . . . 472
Front Axle . . . . . . . . . . . . . . . . . . . . . . 361
Front Fog Lamp Light . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Front Pedestrian Braking
(FPB) System . . . . . . . . . . . . . . . . . 272
Front Seats Adjustment . . . . . . . . . . . . . . . . . . . . . 55
Heated and Ventilated . . . . . . . . . . 61
Fuel
Additives . . . . . . . . . . . . . . . . . . . . . 282
Economy, Driving for Better . . . 186
Filling a Portable FuelContainer . . . . . . . . . . . . . . . . . . . 286
Filling the Tank . . . . . . . . . . 283, 285
Foreign Countries . . . . . . . . . . . . 281
Gauge . . . . . . . . . . . . . . . . . . . . . . . . 132
Low Fuel Warning Light . . . . . . . 146
Management, Active . . . . . . . . . . 219
Prohibited Fuels . . . . . . . . . . . . . . 281
Recommended . . . . . . . . . . 280, 281
Top Tier . . . . . . . . . . . . . . . . . . . . . . 280 Full-Size Spare Tire . . . . . . . . . . . . 418
Fuses
Engine Compartment FuseBlock . . . . . . . . . . . . . . . . . . . . . . . . 371
Fuses and Circuit Breakers . . . 370
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . 374, 376G
Garage Door Opener . . . . . . . . . . . 161
Programming . . . . . . . . . . . . . . . . . 161
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . 365
Gauges
Engine CoolantTemperature . . . . . . . . . . . . . . . . 134
Engine Oil Pressure . . . . . . . . . . 133
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Odometer . . . . . . . . . . . . . . . . . . . . . 132
Speedometer . . . . . . . . . . . . . . . . . 131
Tachometer . . . . . . . . . . . . . . . . . . . 132
Trip Odometer . . . . . . . . . . . . . . . . 132
Voltmeter . . . . . . . . . . . . . . . . . . . . . 135
Warning Lights and Indicators . . . . . . . . . . . . . . . . . . . 126
General Information Service and Maintenance . . . . . 440
Towing . . . . . . . . . . . . . . . . . . . . . . . . 287
Vehicle Care . . . . . . . . . . . . . . . . . . 328

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13337776) - 2020 - CRC - 4/4/19
Index 495
Maintenance Schedule (cont'd)Recommended Fluids and
Lubricants . . . . . . . . . . . . . . . . . . . 453
Transfer Case . . . . . . . . . . . . . . . . 227
Malfunction Indicator Lamp . . . . . 138
Manual Mirrors . . . . . . . . . . . . . . . . . . 41
Manual Mode . . . . . . . . . . . . . . . . . . . 224
Manual Windows . . . . . . . . . . . . . . . . 49
Memory Seats . . . . . . . . . . . . . . . . . . . 59
Messages Engine Power . . . . . . . . . . . . . . . . 156
Vehicle . . . . . . . . . . . . . . . . . . . . . . . 156
Vehicle Speed . . . . . . . . . . . . . . . . 156
Mirror
Rear Camera . . . . . . . . . . . . . . . . . . . 46
Mirrors Automatic Dimming . . . . . . . . . . . . . 44
Automatic DimmingRearview . . . . . . . . . . . . . . . . . . . . . . 46
Blind Spot . . . . . . . . . . . . . . . . . . . . . . 44
Convex . . . . . . . . . . . . . . . . . . . . . . . . . 40
Folding . . . . . . . . . . . . . . . . . . . . . . . . . 43
Heated . . . . . . . . . . . . . . . . . . . . . . . . . 44
Manual . . . . . . . . . . . . . . . . . . . . . . . . . 41
Manual Rearview . . . . . . . . . . . . . . . 46
Power . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Tilt in Reverse . . . . . . . . . . . . . . . . . . 45
Trailer Tow . . . . . . . . . . . . . . . . . . . . . . 41 Mirrors, Interior Rearview . . . . . . . . 46
Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 238
Driver Control . . . . . . . . . . . . . . . . . 238
Monitor System, Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 389
N
NavigationConnected Services . . . . . . . . . . 485
New Vehicle Break-In . . . . . . . . . . . 208
Noise Control System . . . . . . . . . . 362
O
Odometer . . . . . . . . . . . . . . . . . . . . . . . 132 Trip . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Off-Road . . . . . . . . . . . . . . . . . . . . . . . 191 Driving . . . . . . . . . . . . . . . . . . . . . . . . 191
Recovery . . . . . . . . . . . . . . . . . . . . . 190
Oil Engine . . . . . . . . . . . . . . . . . . . . . . . . 339
Engine Oil Life System . . . . . . . 341
Engine Oil Pressure Gauge . . . 133
Pressure Light . . . . . . . . . . . . . . . . 146
Older Children, Restraints . . . . . . . 85
Online Owner Center . . . . . . . . . . . 466
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . 476
OnStar Additional Information . . . . . . . . . . . . . . . . . . . . 479
OnStar Emergency . . . . . . . . . . . . . 478 OnStar Overview . . . . . . . . . . . . . . . 477
OnStar Security . . . . . . . . . . . . . . . . 479
Operating Mode
Overheated EngineProtection . . . . . . . . . . . . . . . . . . . 352
Operation Fog Lamps . . . . . . . . . . . . . . . . . . . 170
Outlets Power . . . . . . . . . . . . . . . . . . . . . . . . 122
Overheated Engine Protection Operating Mode . . . . 352
Overheating, Engine . . . . . . . . . . . . 351
Overview Instrument Panel . . . . . . . . . . . . . . . . 5
P
ParkShifting Out of . . . . . . . . . . . . . . . . 218
Park Assist . . . . . . . . . . . . . . . . . . . . . 257
Parking Brake and P (Park)
Mechanism Check . . . . . . . . . . 364
Extended . . . . . . . . . . . . . . . . . . . . . 219
Over Things That Burn . . . . . . . 219
Parking or Backing Assistance Systems . . . . . . . . . . 257
Passenger Airbag Status Indicator . . . . . . . . . . . . . . . . . . . . . . 137

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13337776) - 2020 - CRC - 4/4/19
Index 499
Traction Control/ElectronicStability Control . . . . . . . . . . . . . . . 235
Trailer Sway Control (TSC) . . . . . . . . . . 308
Tow Mirrors . . . . . . . . . . . . . . . . . . . . . 41
Towing . . . . . . . . . . . . . . . . . . . . . . . . 292
Trailer Towing
App . . . . . . . . . . . . . . . . . . . . . . . . . . . 310
Trailering App . . . . . . . . . . . . . . . . . . 310
Transfer Case . . . . . . . . . . . . . . . . . . 227
Transmission Automatic . . . . . . . . . . . . . . . . . . . . . 221
Fluid, Automatic . . . . . . . . . . . . . . 343
Transportation Program, Courtesy . . . . . . . . . . . . . . . . . . . . . . 469
Trip Odometer . . . . . . . . . . . . . . . . . . 132
Truck-Camper Loading
Information . . . . . . . . . . . . . . . . . . . . 206
Turn and Lane-Change Signals . . . . . . . . . . . . . . . . . . . . . . . . 170
Turn Signal
Bulb Replacement . . . . . . . . . . . . 368U
Underseat Storage . . . . . . . . . . . . . 114
Uniform Tire Quality Grading . . . 401
Universal Remote System . . . . . . 161Operation . . . . . . . . . . . . . . . . . . . . . 164
Programming . . . . . . . . . . . . . . . . . 161
Using This Manual . . . . . . . . . . . . . . . . 2
V
Vehicle Alarm System . . . . . . . . . . . . . . . . . . 37
Canadian Owners . . . . . . . . . . . . . . . 2
Control . . . . . . . . . . . . . . . . . . . . . . . 188
Identification Number (VIN) . . . 458
Load Limits . . . . . . . . . . . . . . . . . . . 200
Messages . . . . . . . . . . . . . . . . . . . . 156
Personalization . . . . . . . . . . . . . . . 157
Remote Start . . . . . . . . . . . . . . . . . . . 24
Security . . . . . . . . . . . . . . . . . . . . . . . . 37
Speed Messages . . . . . . . . . . . . . 156
Towing . . . . . . . . . . . . . . . . . . . . . . . . 424
Vehicle Ahead Indicator . . . . . . . . 143
Vehicle Care Tire Pressure . . . . . . . . . . . . . . . . . 387
Vehicle Data Recording and Privacy . . . . . . . . . . . . . . . . . . . . . . . . 474
Vehicle Security Steering Column Lock . . . . . . . . . . 38 Ventilation, Air . . . . . . . . . . . . . . . . . . 182
Visors . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Voltmeter Gauge . . . . . . . . . . . . . . . 135
W
Warning
Brake System Light . . . . . . . . . . . 140
Caution and Danger . . . . . . . . . . . . . 3
Lane Departure (LDW) . . . . . . . 276
Warning Lights, Gauges, and Indicators . . . . . . . . . . . . . . . . . . . . . 126
Warnings
Hazard Flashers . . . . . . . . . . . . . . 169
Washer Fluid . . . . . . . . . . . . . . . . . . . 354
Wheels Alignment and Tire Balance . . 403
Different Size . . . . . . . . . . . . . . . . . 401
Replacement . . . . . . . . . . . . . . . . . 403
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 398
Where to Put the Restraint . . . . . . 91
Windows . . . . . . . . . . . . . . . . . . . . . . . . 48
Manual . . . . . . . . . . . . . . . . . . . . . . . . . 49
Power . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Windshield
Replacement . . . . . . . . . . . . . . . . . 365
Wiper/Washer . . . . . . . . . . . . . . . . 120