2018 GMC SIERRA transmission

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
314 Driving and Operating
1500/2500/3500 Series Pickups–SAE J2807 Compliant
Vehicle Axle Ratio Maximum Trailer
Weight (c) GCWR (a)
5.3L V8 3.08 2 812 kg (6,200 lb) 5 443 kg (12,000 lb)
5.3L V8 –Gooseneck/Fifth Wheel 3.08 2 767 kg (6,100 lb) 5 443 kg (12,000 lb)
5.3L V8 –Conventional Trailer 3.424 173 kg (9,200 lb) 6 804 kg (15,000 lb)
5.3L V8 –Gooseneck/Fifth Wheel 3.42 4 082 kg (9,000 lb) 6 804 kg (15,000 lb)
5.3L V8, 8-speed automatic
transmission with Enhanced
Towing Package 3.42
4 899 kg (10,800 lb) 7 575 kg (16,700 lb)
5.3L V8 3.734 899 kg (10,800 lb) 7 575 kg (16,700 lb)
6.2L V8 –Conventional Trailer 3.234 128 kg (9,100 lb) 6 804 kg (15,000 lb)
6.2L V8 –Gooseneck/Fifth-Wheel
Trailer 3.23
3 901 kg (8,600 lb) 6 804 kg (15,000 lb)
6.2L V8 –Conventional Trailer 3.425 352 kg (11,800 lb) 8 029 kg (17,700 lb)
6.2L V8 –Gooseneck/Fifth-Wheel
Trailer 3.42
4 990 kg (11,000 lb) 8 029 kg (17,700 lb)
1500 Series 4WD Crew Cab Standard Box 5.3L V8 –Conventional Trailer 3.082 767 kg (6,100 lb) 5 443 kg (12,000 lb)
5.3L V8 –Gooseneck/Fifth-Wheel
Trailer 3.08
2 722 kg (6,000 lb) 5 443 kg (12,000 lb)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 315
1500/2500/3500 Series Pickups–SAE J2807 Compliant
Vehicle Axle Ratio Maximum Trailer
Weight (c) GCWR (a)
5.3L V8 –Conventional Trailer 3.424 128 kg (9,100 lb) 6 804 kg (15,000 lb)
5.3L V8 –Gooseneck/Fifth-Wheel
Trailer 3.42
3 674 kg (8,100 lb) 6 804 kg (15,000 lb)
5.3L V8 –8-speed automatic
transmission with Enhanced
Towing Package - Conventional
Trailer 3.42
4 853 kg (10,700 lb) 7 575 kg (16,700 lb)
5.3L V8, 8-speed automatic
transmission with Enhanced
Towing Package –Gooseneck/
Fifth Wheel Trailer 3.42
4 627 kg (10,200 lb) 7 575 kg (16,700 lb)
5.3L V8 –Conventional Trailer 3.734 853 kg (10,700 lb) 7 575 kg (16,700 lb)
5.3L V8 –Gooseneck/Fifth-Wheel
Trailer 3.73
4 627 kg (10,200 lb) 7 575 kg (16,700 lb)
6.2L V8 –Conventional Trailer 3.234 082 kg (9,000 lb) 6 804 kg (15,000 lb)
6.2L V8 –Gooseneck/Fifth-Wheel
Trailer 3.23
3 629 kg (8,000 lb) 6 804 kg (15,000 lb)
6.2L V8 –Conventional Trailer 3.425 307 kg (11,700 lb) 8 029 kg (17,700 lb)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
316 Driving and Operating
1500/2500/3500 Series Pickups–SAE J2807 Compliant
Vehicle Axle Ratio Maximum Trailer
Weight (c) GCWR (a)
6.2L V8 –Gooseneck/Fifth-Wheel
Trailer 3.42 4 627 kg (10,200 lb) 8 029 kg (17,700 lb)
1500 Series 4WD Crew Cab Short Box (b) 4.3L V6 3.42 3 175 kg (7,000 lb) 5 806 kg (12,800 lb)
5.3L V8 3.08 2 767 kg (6,100 lb) 5 443 kg (12,000 lb)
5.3L V8 3.42 4 128 kg (9,100 lb) 6 804 kg (15,000 lb)
5.3L V8, 8-speed automatic
transmission with Enhanced
Towing Package 3.42 4 853 kg (10,700 lb) 7 575 kg (16,700 lb)
5.3L V8 3.73 4 853 kg (10,700 lb) 7 575 kg (16,700 lb)
6.2L V8 3.23 4 128 kg (9,100 lb) 6 804 kg (15,000 lb)
6.2L V8 3.42 5 307 kg (11,700 lb) 8 029 kg (17,700 lb)
1500 Series 4WD Regular Cab Long Box 4.3L V6 –Conventional Trailer 3.423 357 kg (7,400 lb) 5 806 kg (12,800 lb)
4.3L V6 –Gooseneck/Fifth Wheel 3.42 3 311 kg (7,300 lb) 5 806 kg (12,800 lb)
5.3L V8 –Conventional Trailer 3.082 948 kg (6,500 lb) 5 443 kg (12,000 lb)
5.3L V8 –Gooseneck/Fifth Wheel 3.08 2 903 kg (6,400 lb) 5 443 kg (12,000 lb)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
330 Driving and Operating
.Black: Ground
Be sure to consult the aftermarket
electric brake controller owner ’s
manual to determine wire color
coding of the electric trailer brake
controller. The wire colors on the
brake controller may be different
from the vehicle.
The electric trailer brake controller
should be installed by your dealer or
a qualified service center.
Tow/Haul Mode
Pressing this button at the end of
the shift lever turns on and off the
Tow/Haul Mode.
This indicator light on the instrument
cluster comes on when the Tow/
Haul Mode is on.
Tow/Haul is a feature that assists
when pulling a heavy trailer or a
large or heavy load. See Tow/Haul
Mode 0271.
Tow/Haul is designed to be most
effective when the vehicle and
trailer combined weight is at least
75% of the vehicle's Gross
Combined Weight Rating (GCWR).
See “Weight of the Trailer” under
Trailer Towing 0307. Tow/Haul is
most useful under the following
driving conditions:
. When pulling a heavy trailer or a
large or heavy load through
rolling terrain.
. When pulling a heavy trailer or a
large or heavy load in
stop-and-go traffic. .
When pulling a heavy trailer or a
large or heavy load in busy
parking lots where improved low
speed control of the vehicle is
desired.
Operating the vehicle in Tow/Haul
when lightly loaded or with no trailer
at all will not cause damage.
However, there is no benefit to the
selection of Tow/Haul when the
vehicle is unloaded. Such a
selection when unloaded may result
in unpleasant engine and
transmission driving characteristics
and reduced fuel economy. Tow/
Haul is recommended only when
pulling a heavy trailer or a large or
heavy load.
Integrated Trailer Brake
Control System
The vehicle may have an Integrated
Trailer Brake Control (ITBC) system
for use with electric trailer brakes or
most electric over hydraulic trailer
brakes.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 341
Vehicle Care
General Information
General Information . . . . . . . . . . 342
California Proposition65 Warning . . . . . . . . . . . . . . . . . 343
California Perchlorate Materials Requirements . . . . . 343
Accessories and Modifications . . . . . . . . . . . . . . . . 343
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 344
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 344
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 345
Engine Oil . . . . . . . . . . . . . . . . . . . . 350
Engine Oil Life System . . . . . . . 353
Automatic Transmission Fluid (6-Speed Transmission) . . . . . 354
Automatic Transmission Fluid (8-Speed Transmission) . . . . . 357
Engine Air Cleaner/Filter . . . . . . 358
Cooling System . . . . . . . . . . . . . . 359
Engine Overheating . . . . . . . . . . 363
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . 364
Engine Fan . . . . . . . . . . . . . . . . . . . 365 Power Steering Fluid (1500
Series) . . . . . . . . . . . . . . . . . . . . . . 365
Power Steering Fluid (2500/ 3500 Series) . . . . . . . . . . . . . . . . 365
Washer Fluid . . . . . . . . . . . . . . . . . 366
Brakes . . . . . . . . . . . . . . . . . . . . . . . 367
Brake Fluid . . . . . . . . . . . . . . . . . . . 368
Battery - North America . . . . . . 369
Four-Wheel Drive . . . . . . . . . . . . . 370
Front Axle . . . . . . . . . . . . . . . . . . . . 370
Rear Axle . . . . . . . . . . . . . . . . . . . . 371
Noise Control System . . . . . . . . 373
Starter Switch Check . . . . . . . . . 374
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 374
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . 374
Park Brake and P (Park) Mechanism Check . . . . . . . . . . 375
Wiper Blade Replacement . . . . 375
Windshield Replacement . . . . . 376
Gas Strut(s) . . . . . . . . . . . . . . . . . . 376
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 377
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 378
Halogen Bulbs . . . . . . . . . . . . . . . . 378 High Intensity Discharge (HID)
Lighting . . . . . . . . . . . . . . . . . . . . . 378
LED Lighting . . . . . . . . . . . . . . . . . 378
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 378
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . 380
Electrical System
High Voltage Devices andWiring . . . . . . . . . . . . . . . . . . . . . . . 380
Electrical System Overload . . . 380
Fuses and Circuit Breakers . . . 381
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 381
Instrument Panel Fuse Block (Right) . . . . . . . . . . . . . . . . . . . . . . 385
Instrument Panel Fuse Block (Left) . . . . . . . . . . . . . . . . . 386
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 389
All-Season Tires . . . . . . . . . . . . . . 389
Winter Tires . . . . . . . . . . . . . . . . . . 390
Low-Profile Tires . . . . . . . . . . . . . 390
All-Terrain Tires . . . . . . . . . . . . . . . 391
Tire Sidewall Labeling . . . . . . . . 391
Tire Designations . . . . . . . . . . . . . 393

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
346 Vehicle Care
1. Positive (+) Terminal. SeeJump Starting - North America
0426.
2. Battery - North America 0369.
3. Coolant Surge Tank and Pressure Cap. See Cooling
System 0359.
4. Engine Air Cleaner/Filter 0358.
5. Automatic Transmission Dipstick (If Equipped). See
“How to Check Automatic
Transmission Fluid” under
Automatic Transmission Fluid
(6-Speed Transmission) 0354
or Automatic Transmission
Fluid (8-Speed Transmission)
0 357. 6. Remote Negative (–) Location.
See Jump Starting - North
America 0426.
7. Engine Cooling Fans (Out of View). See Cooling System
0 359.
8. Engine Oil Fill Cap. See “When
to Add Engine Oil” under
Engine Oil 0350.
9. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil 0350. 10. Brake Fluid Reservoir. See
Brake Fluid 0368.
11. Windshield Washer Fluid Reservoir. See “Adding Washer
Fluid” under Washer Fluid
0 366.
12. Engine Compartment Fuse
Block 0381.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
348 Vehicle Care
1. Positive (+) Terminal. SeeJump Starting - North America
0426.
2. Battery - North America 0369.
3. Coolant Surge Tank and Pressure Cap. See Cooling
System 0359.
4. Engine Air Cleaner/Filter 0358.
5. Automatic Transmission Dipstick (If Equipped). See
“How to Check Automatic
Transmission Fluid” under
Automatic Transmission Fluid
(6-Speed Transmission) 0354
or Automatic Transmission
Fluid (8-Speed Transmission)
0 357. 6. Remote Negative (–) Location
(Out of View). See Jump
Starting - North America 0426.
7. Engine Cooling Fans (Out of View). See Cooling System
0 359.
8. Engine Oil Fill Cap. See “When
to Add Engine Oil” under
Engine Oil 0350.
9. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil 0350. 10. Windshield Washer Fluid
Reservoir. See “Adding Washer
Fluid” under Washer Fluid
0 366.
11. Brake Fluid Reservoir. See Brake Fluid 0368.
12. Engine Compartment Fuse
Block 0381.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
350 Vehicle Care
1. Positive (+) Terminal. SeeJump Starting - North America
0426.
2. Battery - North America 0369.
3. Coolant Surge Tank and Pressure Cap. See Cooling
System 0359.
4. Engine Air Cleaner/Filter 0358.
5. Automatic Transmission Dipstick (If Equipped). See
“How to Check Automatic
Transmission Fluid” under
Automatic Transmission Fluid
(6-Speed Transmission) 0354
or Automatic Transmission
Fluid (8-Speed Transmission)
0 357.
6. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil 0350.
7. Engine Oil Fill Cap. See “When
to Add Engine Oil” under
Engine Oil 0350.
8. Engine Cooling Fan (Out of View). See Cooling System
0 359. 9. Remote Negative (–) Location.
See Jump Starting - North
America 0426.
10. Power Steering Fluid Reservoir. See Power Steering
Fluid (1500 Series) 0365 or
Power Steering Fluid (2500/
3500 Series) 0365.
11. Windshield Washer Fluid Reservoir. See “Adding Washer
Fluid” under Washer Fluid
0 366.
12. Brake Fluid Reservoir. See Brake Fluid 0368.
13. Auxiliary Battery (If Equipped). SeeBattery - North America
0 369.
14. Engine Compartment Fuse
Block 0381.
If the vehicle has a diesel engine
and/or an Allison Transmission, see
the Duramax diesel supplement.
For an eAssist vehicle, see the
Silverado/Sierra supplement.Engine Oil
For diesel engine vehicles, see
“Engine Oil” in the Duramax diesel
supplement.
To ensure proper engine
performance and long life, careful
attention must be paid to engine oil.
Following these simple, but
important steps will help protect
your investment:
. Use engine oil approved to the
proper specification and of the
proper viscosity grade. See
“Selecting the Right Engine Oil”
in this section.
. Check the engine oil level
regularly and maintain the
proper oil level. See “Checking
Engine Oil” and“When to Add
Engine Oil” in this section.
. Change the engine oil at the
appropriate time. See Engine Oil
Life System 0353.
. Always dispose of engine oil
properly. See “What to Do with
Used Oil” in this section.