2006 GMC Sierra Owners Manual

important information about towing a trailer with your vehicle. To identify the trailering capacity of your vehicle, you should read the information in “Weight of the Trailer” that appears later in this section. Trailering is different than just driving your vehicle by itself. Trailering means changes in acceleration, braking, handling, durability and fuel economy. Successful, safe trailering takes correct equipment, and it has to be used properly. That’s the reason for this part. In it are many time-tested, important trailering tips and safety rules. Many of these are important for your safety and that of your passengers. So please read this section carefully before you pull a trailer.

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If You Do Decide To Pull A Trailer If you do, here are some important points:

There are many different laws, including speed limit restrictions, having to do with trailering. Make sure your rig will be legal, not only where you live but also where you’ll be driving. A good source for this information can be state or provincial police.

(cid:127) Consider using a sway control. See “Hitches” later in

this section.

(cid:127) Don’t tow a trailer at all during the first

500 miles (800 km) your new vehicle is driven. Your engine, axle or other parts could be damaged. Then, during the first 500 miles (800 km) that you tow a trailer, don’t drive over 50 mph (80 km/h) and don’t make starts at full throttle. This helps your engine and other parts of your vehicle wear in at the heavier loads. If you have an automatic transmission, you can tow in DRIVE (D). You may want to shift the transmission to THIRD (3) or, if necessary, a lower gear selection if the transmission shifts too often, such as under heavy loads and/or hilly conditions. If you have a manual transmission and you are towing a trailer, it’s better not to use the highest gear. See Tow/Haul Mode Light on page 3-50.

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Three important considerations have to do with weight:

The weight of the trailer The weight of the trailer tongue The weight on your vehicle’s tires

Tow/Haul Mode Tow/Haul is a feature on automatic transmission equipped vehicles that assists when pulling a heavy trailer or a large or heavy load. See Tow/Haul Mode on page 2-31 for more information. Tow/Haul is designed to be most effective when the vehicle and trailer combined weight is at least 75 percent of the vehicle’s Gross Combined Weight Rating (GCWR). See “Weight of the Trailer” later in the section. Tow/Haul is most useful under the following driving conditions: (cid:127) When pulling a heavy trailer or a large or heavy load

through rolling terrain.

(cid:127) When pulling a heavy trailer or a large or heavy load

in stop and go traffic.

(cid:127) 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.

(cid:127) (cid:127) (cid:127) (cid:127) (cid:127) (cid:127) 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. Weight of the Trailer How heavy can a trailer safely be? It depends on how you plan to use your rig. For example, speed, altitude, road grades, outside temperature and how much your vehicle is used to pull a trailer are all important. It can also depend on any special equipment that you have on your vehicle, and the amount of tongue weight the vehicle can carry. See “Weight of the Trailer Tongue” later in this section for more information.

Maximum trailer weight is calculated assuming only the driver is in the tow vehicle and it has all the required trailering equipment. The weight of additional optional equipment, passengers and cargo in the tow vehicle must be subtracted from the maximum trailer weight. Above the 5,000 lb (2 268 kg) trailer rating, the handling/trailering suspension is required on C-1500 models and the handling/trailering or off-road suspension is required on K-1500 models. Use one of the following charts to determine how much your vehicle can weigh, based upon your vehicle model and options.

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Vehicle* C-1500 Regular Cab Short Box (2WD)* 4300 V6 (Auto) 4300 V6 (Manual)

Axle Ratio Maximum Trailer Weight

3.23
3.23
3.23
3.73
3.23
3.73
3.23
3.73

5,000 lbs (2 268 kg) 4,000 lbs (1 814 kg) 6,400 lbs (2 903 kg) 7,400 lbs (3 357 kg) 4,400 lbs (1 996 kg) 5,400 lbs (2 449 kg) 7,400 lbs (3 357 kg) 8,400 lbs (3 810 kg)

4800 V8 (Auto)

4800 V8 (Manual)

5300 V8

GCWR

9,500 lbs (4 309 kg) 8,500 lbs (3 855 kg) 11,000 lbs (4 994 kg) 12,000 lbs (5 443 kg) 9,000 lbs (4 082 kg) 10,000 lbs (4 535 kg) 12,000 lbs (5 443 kg) 13,000 lbs (5 897 kg)

* Fifth-wheel or gooseneck kingpin weight 15 percent to 25 percent of trailer weight up to 1,500 lbs (680 kg) maximum.

Vehicle* C-1500 Extended Cab Short Box (2WD)*

Axle Ratio Maximum Trailer Weight

GCWR

4300 V6 (Auto)

4300 V6 (Manual)

4800 V8 (Auto)

4800 V8 (Manual)

5300 V8

3.23
3.73
3.23
3.23
3.73
3.23
3.73
3.23
3.73

4,600 lbs (2 087 kg) 5,100 lbs (2 313 kg) 3,600 lbs (1 633 kg) 5,900 lbs (2 676 kg) 6,900 lbs (3 130 kg) 3,900 lbs (1 769 kg) 4,900 lbs (2 222 kg) 6,900 lbs (3 130 kg) 7,900 lbs (3 583 kg)**

9,500 lbs (4 309 kg) 10,000 lbs (4 536 kg) 8,500 lbs (3 859 kg) 11,000 lbs (4 990 kg) 12,000 lbs (5 443 kg) 9,000 lbs (4 086 kg) 10,000 lbs (4 540 kg) 12,000 lbs (5 443 kg) 13,000 lbs (5 897 kg)

* Fifth-wheel or gooseneck kingpin weight 15 percent to 25 percent of trailer weight up to 1,500 lbs (680 kg) maximum. **Maximum 8,000 lbs (3 628 kg) for fifth-wheel or gooseneck.

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Vehicle* C-1500 HD (2WD)*

Axle Ratio Maximum Trailer Weight

GCWR

6000 V8

14,000 lbs (6 350 kg) 16,000 lbs (7 257 kg) * Fifth-wheel or gooseneck kingpin weight 15 percent to 25 percent of trailer weight up to 2,500 lbs (1 133 kg) maximum.

8,300 lbs (3 765 kg) 10,300 lbs (4 672 kg)

3.73
4.10

Axle Ratio Maximum Trailer Weight

GCWR

Vehicle* C-1500 Crew Cab (2WD)*

5300 V8

6000 V8
Fifth-wheel or gooseneck trailering is neither designed nor intended for this vehicle

6,700 lbs (3 039 kg) 7,700 lbs (3 493 kg) 10,100 lbs (4 581 kg)

Axle Ratio Maximum Trailer Weight

GCWR

Vehicle* C-1500 Regular Cab Long Box (2WD)* 4300 V6 (Auto) 4300 V6 (Manual)

4800 V8 (Auto)

4800 V8 (Manual)

5300 V8

4,800 lbs (2 177 kg) 3,800 lbs (1 724 kg) 6,200 lbs (2 812 kg) 7,200 lbs (3 266 kg) 4,200 lbs (1 905 kg) 5,200 lbs (2 359 kg) 7,200 lbs (3 266 kg) 8,200 lbs (3 719 kg)

3.23
3.73
3.73

3.23
3.23
3.23
3.73
3.23
3.73
3.23
3.73

12,000 lbs (5 443 kg) 13,000 lbs (5 897 kg) 15,500 lbs (7 031 kg)

9,500 lbs (4 313 kg) 8,500 lbs (3 859 kg) 11,000 lbs (4 994 kg) 12,000 lbs (5 448 kg) 9,000 lbs (4 086 kg) 10,000 lbs (4 540 kg) 12,000 lbs (5 448 kg) 13,000 lbs (5 902 kg)

* Fifth-wheel or gooseneck kingpin weight 15 percent to 25 percent of trailer weight up to 1,500 lbs (680 kg) maximum.

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Vehicle* C-1500 Extended Cab Long Box (2WD)*

Axle Ratio Maximum Trailer Weight

GCWR

4800 V8 (Auto)

4800 V8 (Manual)

5300 V8

3.23
3.73
3.23
3.73
3.42
3.73

5,800 lbs (2 631 kg) 6,800 lbs (3 084 kg) 3,800 lbs (1 724 kg) 4,800 lbs (2 177 kg) 6,800 lbs (3 084 kg) 7,800 lbs (3 538 kg)

11,000 lbs (4 994 kg) 12,000 lbs (5 448 kg) 9,000 lbs (4 086 kg) 10,000 lbs (4 540 kg) 12,000 lbs (5 448 kg) 13,000 lbs (5 902 kg)

* Fifth-wheel or gooseneck kingpin weight 15 percent to 25 percent of trailer weight up to 1,500 lbs (680 kg) maximum.

Vehicle* K-1500 Regular Cab Short Box (4WD) 4300 V6 (Auto) 4300 V6 (Manual)

Axle Ratio Maximum Trailer Weight

3.73
3.73
3.42
3.73
4.10
3.42
3.73
4.10
3.42
3.73
4.10

5,100 lbs (2 313 kg) 4,100 lbs (1 860 kg) 7,100 lbs (3 221 kg) 7,100 lbs (3 221 kg) 8,100 lbs (3 674 kg) 5,100 lbs (2 313 kg) 5,100 lbs (2 313 kg) 6,100 lbs (2 767 kg) 8,100 lbs (3 674 kg) 8,000 lbs (3 674 kg) 9,100 lbs (4 128 kg)

4800 V8 (Auto)

4800 V8 (Manual)

5300 V8

GCWR

10,000 lbs (4 540 kg) 9,000 lbs (4 086 kg) 12,000 lbs (5 448 kg) 12,000 lbs (5 448 kg) 13,000 lbs (5 902 kg) 10,000 lbs (4 540 kg) 10,000 lbs (4 540 kg) 11,000 lbs (4 994 kg) 13,000 lbs (5 902 kg) 13,000 lbs (5 902 kg) 14,000 lbs (6 356 kg)

* Fifth-wheel or gooseneck kingpin weight 15 percent to 25 percent of trailer weight up to 1,500 lbs (680 kg) maximum.

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Vehicle* K-1500 Extended Cab Short Box (4WD)*

Axle Ratio Maximum Trailer Weight

GCWR

4800 V8 (Auto)

4800 V8 (Manual)

6,700 lbs (3 039 kg) 6,700 lbs (3 039 kg) 7,700 lbs (3 493 kg)** 4,700 lbs (2 132 kg) 4,700 lbs (2 132 kg) 5,700 lbs (2 585 kg) 7,700 lbs (3 493 kg)** 7,700 lbs (3 493 kg)** 8,700 lbs (3 946 kg)** ** Maximum weight 7,700 lbs. (3 492 kg) for fifth-wheel or gooseneck. K-1500 HD (4WD)*

3.42
3.73
4.10
3.42
3.73
4.10
3.42
3.73
4.10

5300 V8

12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg) 13,000 lbs (5 897 kg) 10,000 lbs (4 535 kg) 10,000 lbs (4 535 kg) 11,000 lbs (4 990 kg) 13,000 lbs (5 897 kg) 13,000 lbs (5 897 kg) 14,000 lbs (6 350 kg)

6000 V8

3.73
4.10

7,900 lbs (3 583 kg) 9,900 lbs (4 491 kg)

14,000 lbs (6 350 kg) 16,000 lbs (7 257 kg)

Axle Ratio Maximum Trailer Weight

GCWR

Vehicle* K-1500 Crew Cab (4WD)*

5300 V8

3.42
3.73
4.10
4.10

7,400 lbs (3 357 kg) 7,400 lbs (3 357 kg) 8,400 lbs (3 810 kg) 9,800 lbs (4 445 kg)

13,000 lbs (5 897 kg) 13,000 lbs (5 897 kg) 14,000 lbs (6 350 kg) 15,500 lbs (7 031 kg)

6000 V8** *Fifth-wheel or gooseneck trailering is neither designed nor intended for this vehicle. **Trailer tongue weight should be 10 to 15 percent of total loaded trailer weight up to 1,200 lbs (544 kg) on models with NHT Enhanced Trailering Performance.

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Vehicle* K-1500 Regular Cab Long Box (4WD)* 4300 V6 (Auto) 4300 V6 (Manual)

Axle Ratio Maximum Trailer Weight

3.73
3.73
3.42
3.73
4.10
3.42
3.73
4.10
3.42
3.73
4.10

5,000 lbs (2 268 kg) 4,000 lbs (1 814 kg) 6,900 lbs (3 130 kg) 6,900 lbs (3 130 kg) 7,900 lbs (3 583 kg) 4,900 lbs (2 223 kg) 4,900 lbs (2 223 kg) 5,900 lbs (2 676 kg) 7,900 lbs (3 583 kg) 7,900 lbs (3 583 kg) 8,900 lbs (4 037 kg)**

4800 V8 (Auto)

4800 V8 (Manual)

5300 V8

GCWR

10,000 lbs (4 536 kg) 9,000 lbs (4 082 kg) 12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg) 13,000 lbs (5 897 kg) 10,000 lbs (4 536 kg) 10,000 lbs (4 536 kg) 11,000 lbs (4 990 kg) 13,000 lbs (5 897 kg) 13,000 lbs (5 897 kg) 14,000 lbs (6 350 kg)

*Fifth-wheel or gooseneck kingpin weight 15 percent to 25 percent of trailer weight up to 1,500 lbs (680 kg) maximum. **Maximum weight 8,900 lbs (4 036 kg) for fifth-wheel and gooseneck.

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Vehicle* K-1500 Extended Cab Long Box (4WD)*

Axle Ratio Maximum Trailer Weight

GCWR

4800 V8

4800 V8 (Manual)

5300 V8

3.42
3.73
4.10
3.42
3.73
4.10
3.42
3.73
4.10

6,500 lbs (2 948 kg) 6,500 lbs (2 948 kg) 7,500 lbs (3 402 kg) 4,500 lbs (2 041 kg) 4,500 lbs (2 041 kg) 5,500 lbs (2 495 kg) 7,500 lbs (3 402 kg)** 7,500 lbs (3 402 kg)** 8,500 lbs (3 856 kg)**

12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg) 13,000 lbs (5 897 kg) 10,000 lbs (4 536 kg) 10,000 lbs (4 536 kg) 11,000 lbs (4 990 kg) 13,000 lbs (5 897 kg) 13,000 lbs (5 897 kg) 14,000 lbs (6 350 kg)

*Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 1,500 lbs (680 kg) maximum. **Maximum weight 6,800 lbs (3 084 kg) for fifth-wheel and gooseneck.

Vehicle* C-2500 Regular Cab Long Box HD (2WD)* 6000 V8

Axle Ratio Maximum Trailer Weight

GCWR

8100 V8

6.6L V8 Diesel

4.10
3.73
4.10
3.73

10,500 lbs (4 763 kg) 12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg)

16,000 lbs (7 257 kg) 20,000 lbs (9 072 kg) 22,000 lbs (9 979 kg) 22,000 lbs (9 979 kg)

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Axle Ratio Maximum Trailer Weight

GCWR

Vehicle* C-2500 Extended Cab Short Box HD (2WD)* 6000 V8

8100 V8

6.6L V8 Diesel *Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,000 lbs (1 361 kg) maximum. Fifth-wheel or gooseneck GCWR for 6.6L V8 Diesel 2500 HD series models is 23,200 lbs (10 523 kg).

10,200 lbs (4 627 kg) 12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg)

16,000 lbs (7 257 kg) 20,000 lbs (9 072 kg) 22,000 lbs (9 979 kg) 22,000 lbs (9 979 kg)

Vehicle* C-2500 Extended Cab Long Box HD (2WD)* 6000 V8

Axle Ratio Maximum Trailer Weight

GCWR

8100 V8

8100 V8

6.6L V8 Diesel C-2500 Crew Cab Short Box HD (2WD) 6000 V8

10,100 lbs (4 581 kg) 12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg)

16,000 lbs (7 257 kg) 20,000 lbs (9 072 kg) 22,000 lbs (9 979 kg) 22,000 lbs (9 979 kg)

10,100 lbs (4 581 kg) 12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg)

16,000 lbs (7 257 kg) 20,000 lbs (9 072 kg) 22,000 lbs (9 979 kg) 22,000 lbs (9 979 kg)

4.10
3.73
4.10
3.73

4.10
3.73
4.10
3.73

4.10
3.73
4.10
3.73

6.6L V8 Diesel *Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,000 lbs (1 361 kg) maximum.

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Axle Ratio Maximum Trailer Weight

GCWR

Vehicle* C-2500 Crew Cab Long Box HD (2WD) 6000 V8

8100 V8

4.10
3.73
4.10
3.73

10,000 lbs (4 536 kg) 12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg)

16,000 lbs (7 257 kg) 20,000 lbs (9 072 kg) 22,000 lbs (9 979 kg) 22,000 lbs (9 979 kg)

6.6L V8 Diesel *Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,000 lbs (1 361 kg) maximum.

Vehicle* K-1500 HD (4WD)*

6000 V8

Axle Ratio Maximum Trailer Weight

GCWR

3.73
4.10

7,900 lbs (3 583 kg) 9,900 lbs (4 491 kg)

14,000 lbs (6 350 kg) 16,000 lbs (7 257 kg)

*Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,000 lbs (1 361 kg) maximum.

Axle Ratio Maximum Trailer Weight

GCWR

Vehicle* K-2500 Regular Cab Long Box HD (4WD)* 6000 V8

8100 V8

4.10
3.73
4.10
3.73

10,300 lbs (4 672 kg) 12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg)

6.6L V8 Diesel *Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,000 lbs (1 361 kg) maximum. Fifth-wheel or gooseneck GCWR for 6.6L V8 Diesel 2500 HD series models is 23,200 lbs (10 523 kg).

16,000 lbs (7 257 kg) 20,000 lbs (9 072 kg) 22,000 lbs (9 979 kg) 22,000 lbs (9 979 kg)

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Axle Ratio Maximum Trailer Weight

GCWR

Vehicle* K-2500 Extended Cab Short Box HD (4WD)* 6000 V8

8100 V8

6.6L V8 Diesel *Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,000 lbs (1 361 kg) maximum. Fifth-wheel or gooseneck GCWR for 6.6L V8 Diesel 2500 HD series models is 23,200 lbs (10 523 kg).

10,000 lbs (4 536 kg) 12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg)

16,000 lbs (7 257 kg) 20,000 lbs (9 072 kg) 22,000 lbs (9 979 kg) 22,000 lbs (9 979 kg)

Vehicle* K-2500 Extended Cab Long Box HD (4WD)* 6000 V8

Axle Ratio Maximum Trailer Weight

GCWR

8100 V8

8100 V8

6.6L V8 Diesel K-2500 Crew Cab Short Box HD (4WD)* 6000 V8

9,900 lbs (4 490 kg) 12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg)

16,000 lbs (7 257 kg) 20,000 lbs (9 072 kg) 22,000 lbs (9 979 kg) 22,000 lbs (9 979 kg)

9,800 lbs (4 445 kg) 12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg)

16,000 lbs (7 257 kg) 20,000 lbs (9 072 kg) 22,000 lbs (9 979 kg) 22,000 lbs (9 979 kg)

4.10
3.73
4.10
3.73

4.10
3.73
4.10
3.73

4.10
3.73
4.10
3.73

6.6L V8 Diesel *Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,000 lbs (1 361 kg) maximum.

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Vehicle* K-2500 Crew Cab Long Box HD (4WD) 6000 V8

Axle Ratio Maximum Trailer Weight

GCWR

8100 V8

16,000 lbs (7 257 kg) 20,000 lbs (9 072 kg) 22,000 lbs (9 979 kg) 6.6L V8 Diesel 22,000 lbs (9 979 kg) * Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,000 lbs (1 361 kg) maximum.

9,700 lbs (4 400 kg) 12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg) 12,000 lbs (5 443 kg)

4.10
3.73
4.10
3.73

GCWR

4.10
4.10
3.73
3.73

9,700 lbs (4 400 kg)

Axle Ratio Maximum Trailer Weight

Vehicle* C-3500 Extended Cab (2WD) 6000 V8
8100 V8
6.6L V8 Diesel (Manual) 6.6L V8 Diesel (Auto) C-3500 Crew Cab (2WD)* 6000 V8
8100 V8
6.6L V8 Diesel (Manual) 6.6L V8 Diesel (Auto) *Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,500 lbs (1 587 kg) maximum. ** Limited to 12,000 lbs (5 443 kg) with weight distributing hitch.

12,000 lbs (5 543 kg)** 12,000 lbs (5 543 kg)** 12,000 lbs (5 443 kg)

12,000 lbs (5 443 kg)** 12,000 lbs (5 443 kg)** 12,000 lbs (5 443 kg)

9,500 lbs (4 309 kg)

4.10
4.10
3.73
3.73

16,000 lbs (7 257 kg) 22,000 lbs (9 979 kg) 23,500 lbs (10 659 kg) 23,500 lbs (10 659 kg)

16,000 lbs (7 257 kg) 22,000 lbs (9 979 kg) 23,500 lbs (10 659 kg) 23,500 lbs (10 659 kg)

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Vehicle* K-3500 Regular Cab (4WD) 6000 V8 Dual Rear Wheel 6000 V8 Single Rear Wheel 8100 V8 Dual Rear Wheel 8100 V8 Single Rear Wheel 6.6L V8 Dual Rear Wheel (Auto) 6.6L V8 Dual Rear Wheel (Manual) 6.6L V8 Single Rear Wheel

Axle Ratio Maximum Trailer Weight

GCWR

4.10

4.10

4.10

4.10

3.73

3.73

3.73

9,800 lbs (4 445 kg)

16,000 lbs (7 257 kg)

10,000 lbs (4 536 kg)

16,000 lbs (7 257 kg)

15,400 lbs (6 985 kg)

22,000 lbs (9 979 kg)

15,600 lbs (7 067 kg)

22,000 lbs (9 979 kg)

16,700 lbs (7 575 kg)

23,500 lbs (10 659 kg)

16,700 lbs (7 575 kg)

23,500 lbs (10 659 kg)

15,400 lbs (6 985 kg)

22,000 lbs (9 979 kg)

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4.10

4.10

4.10

GCWR

9,600 lbs (4 354 kg)

9,400 lbs (4 264 kg)

Axle Ratio Maximum Trailer Weight

Vehicle* K-3500 Extended Cab (4WD)* 6000 V8 Dual Rear Wheel 6000 V8 Single Rear Wheel 8100 V8 Dual Rear Wheel 8100 V8 Single Rear Wheel 6.6L V8 Diesel Dual Rear Wheel (Manual) 6.6L V8 Diesel Dual Rear Wheel (Auto) 6.6L V8 Diesel Single Rear Wheel * Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,500 lbs (1 587 kg) maximum. Fifth-wheel or gooseneck GCWR for 6.6L V8 Diesel 3500 SRW series models is 23,200 lbs (10 523 kg).

16,300 lbs (7 394 kg)

15,000 lbs (6 804 kg)

15,000 lbs (6 804 kg)

16,300 lbs (7 394 kg)

15,000 lbs (6 804 kg)

4.10

3.73

3.73

3.73

16,000 lbs (7 257 kg)

16,000 lbs (7 257 kg)

22,000 lbs (9 979 kg)

22,000 lbs (9 979 kg)

22,000 lbs (9 979 kg)

23,500 lbs (10 659 kg)

23,500 lbs (10 659 kg)

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16,000 lbs (7 264 kg)

16,000 lbs (7 264 kg)

4.10

4.10

4.10

GCWR

9,400 lbs (4 264 kg)

9,200 lbs (4 173 kg)

12,000 lbs (5 443 kg)

Axle Ratio Maximum Trailer Weight

Vehicle* K-3500 Crew Cab (4WD)* 6000 V8 Dual Rear Wheel 6000 V8 Single Rear Wheel 8100 V8 Dual Rear Wheel 8100 V8 Single Rear Wheel 6.6L V8 Diesel Single Rear Wheel (Auto) 6.6L V8 Diesel Single Rear Wheel (Manual) 6.6L V8 Diesel Dual Rear Wheel (Auto) 6.6L V8 Diesel Dual Rear Wheel (Manual) *Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,500 lbs (1 587 kg) maximum. Fifth-wheel or gooseneck GCWR for 6.6L V8 Diesel 3500 SRW series models is 23,200 lbs (10 523 kg).

12,000 lbs (5 443 kg)

12,000 lbs (5 443 kg)

12,000 lbs (5 443 kg)

12,000 lbs (5 443 kg)

12,000 lbs (5 443kg)

4.10

3.73

3.73

3.73

3.73

22,000 lbs (9 979 kg)

22,000 lbs (9 979 kg)

22,000 lbs (9 979 kg)

22,000 lbs (9 979 kg)

23,500 lbs (10 659 kg)

23,500 lbs (10 659 kg)

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The Gross Combination Weight Rating (GCWR) is the total allowable weight of the completely loaded vehicle and trailer including any passengers, cargo, equipment and conversions. The GCWR for your vehicle should not be exceeded. You can ask your dealer for our trailering information or advice, or you can write us at the address listed in your Warranty and Owner Assistance Information Booklet. In Canada, write to:

General Motors of Canada Limited Customer Communications Centre, 163-005
1908 Colonel Sam Drive Oshawa, Ontario L1H 8P7

Weight of the Trailer Tongue The tongue load (A) of any trailer is an important weight to measure because it affects the total or gross weight of your vehicle. The Gross Vehicle Weight (GVW) includes the curb weight of the vehicle, any cargo you may carry in it, and the people who will be riding in the vehicle. If you have a lot of options, equipment, passengers or cargo in your vehicle, it will reduce the tongue weight your vehicle can carry, which will also reduce the trailer weight your vehicle can tow. And if you will tow a trailer, you must add the tongue load to the GVW because your vehicle will be carrying that weight, too. See Loading Your Vehicle on page 4-48 for more information about your vehicle’s maximum load capacity.

The trailer tongue weight (A) should be 10 percent to 15 percent of the total loaded trailer weight, up to a maximum of 600 lbs (272 kg) for the 1500 or 2500 series, and up to a maximum of 750 lbs (340 kg) for the 2500 HD or 3500 series with a weight carrying hitch. The trailer tongue weight (A) should be 10 percent to 15 percent of the total loaded trailer weight, up to a maximum of 1,000 lbs (453 kg) for the 1500 series and up to a maximum of 1,500 lbs (680 kg) for the 2500, 2500 HD or 3500 series with a weight distributing hitch. Fifth wheel or gooseneck kingpin weight should be 15 to 25 percent of the trailer weight up to the maximum amount specified in the trailering chart for your vehicle. See “Weight of the Trailer”, and “Fifth-Wheel and Gooseneck Trailering” in this section.

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Do not exceed the maximum allowable tongue weight for your vehicle. Choose the shortest hitch extension that will position the hitch ball closest to the vehicle. This will help reduce the effect of trailer tongue weight on the rear axle. After you have loaded the trailer, weigh the trailer and then the tongue separately, to see if the weights are proper. If they are not, you may be able to get them right by moving some items around in the trailer. Trailering may be limited by the vehicle’s ability to carry tongue weight. Tongue weight cannot cause the vehicle to exceed the GVWR (Gross Vehicle Weight Rating) or the RGAWR (Rear Gross Axle Weight Rating). The effect of additional weight may reduce your trailering capacity more than the total of the additional weight.

Consider the following example: A vehicle model base weight is 5,500 lbs (2 495 kg); 2,800 lbs (1 270 kg) at the front axle and 2,700 lbs (1 225 kg) at the rear axle. It has a GVWR of 7,200 lbs (3 266 kg), a RGAWR of 4,000 lbs (1 814 kg) and a GCWR (Gross Combination Weight Rating) of 14,000 lbs (6 350 kg). The trailer rating should be:

You can expect tongue weight to be at least 10 percent of trailer weight (850 lbs (386 kg)) and because the weight is applied well behind the rear axle, the effect on the rear axle will be greater than just the weight itself, as much as 1.5 times as much. The weight at the rear axle could be 850 lbs (386 kg) X 1.5 = 1,275 lbs (578 kg). Since the rear axle already weighs 2,700 lbs (1 225 kg), adding 1,275 lbs (578 kg) brings the total to 3,975 lbs (1 803 kg). This is very close to, but within the limit for RGAWR as well. The vehicle is set to trailer up to 8,500 lbs (3 856 kg).

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But let’s say your specific vehicle is equipped with some of the latest options and you have a front seat passenger and two rear seat passengers with some luggage and gear in the vehicle as well. You may add 300 lbs (136 kg) to the front axle weight and 400 lbs (181 kg) to the rear axle weight. Your vehicle now weighs:

Weight is still below 7,200 lbs (3 266 kg) and you may think that you should subtract 700 additional pounds (318 kg) from your trailering capacity to stay within GCWR limits. Your maximum trailer would only be 7,800 lbs (3 538 kg). You may go further and think you must limit tongue weight to less than 1,000 lbs (454 kg) to avoid exceeding GVWR. But, you must still consider the effect on the rear axle. Because your rear axle now weighs 3,100 lbs (1 406 kg), you can only put 900 lbs (408 kg) on the rear axle without exceeding RGAWR. The effect of tongue weight is about 1.5 times the actual weight. Dividing the 900 lbs (408 kg) by 1.5 leaves you with being able to handle only 600 lbs (272 kg) of tongue weight.

Since tongue weight is usually at least 10 percent of total loaded trailer weight, you can expect that the largest trailer your vehicle can properly handle is 6,000 lbs (2 721 kg). It is important that you make sure your vehicle does not exceed any of its ratings — GCWR, GVWR, RGAWR, Maximum Trailer Rating or Tongue Weight. The only way to be sure you are not exceeding any of these ratings is to weigh your vehicle and trailer. Total Weight on Your Vehicle’s Tires Be sure your vehicle’s tires are inflated to the upper limit for cold tires. You’ll find these numbers on the Certification label at the rear edge of the driver’s door or see Loading Your Vehicle for more information. Then be sure you don’t go over the GVW limit for your vehicle, or the GAWR, including the weight of the trailer tongue. If you use a weight distributing hitch, make sure you don’t go over the rear axle limit before you apply the weight distribution spring bars. Hitches It’s important to have the correct hitch equipment. Crosswinds, large trucks going by and rough roads are a few reasons why you’ll need the right hitch.

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If you use a step-bumper hitch, the bumper could be damaged in sharp turns. Make sure there is ample room when turning to avoid contact between the trailer and the bumper. If you will be pulling a trailer that, when loaded, will weigh more than 5,000 lbs (2 270 kg) be sure to use a properly mounted weight-distributing hitch and sway control of the proper size. This equipment is very important for proper vehicle loading and good handling when driving. Always use a sway control if the trailer will weigh more than these limits. You can ask a hitch dealer about sway controls. Fifth Wheel and Gooseneck Trailering Notice: Pulling a fifth-wheel trailer with a vehicle that is equipped with the SS trim package could damage the vehicle. Do not pull a fifth-wheel trailer with a vehicle equipped with the SS trim package. Fifth wheel and gooseneck trailers can be used with many pickup models. These trailers place a larger percentage of the weight (kingpin weight) on the tow vehicle than conventional trailers. Make sure this weight does not cause the vehicle to exceed GAWR or GVWR.

Weight Distributing Hitches and Weight Carrying Hitches

A: Body to Ground Distance

B: Front of Vehicle When using a weight-distributing hitch, the hitch must be adjusted so the distance (A) remains the same both before and after coupling the trailer to the tow vehicle.

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Fifth wheel or gooseneck kingpin weight should be 15 to 25 percent of the trailer weight up to the maximum amount specified in the trailering chart for your vehicle. See “Weight of the Trailer” in this section for more information. The hitch should be located in the pickup bed so that its centerline is over or slightly in front of the rear axle. Take care that it is not so far forward that it will contact the back of the cab in sharp turns. This is especially important for short box pickups. Trailer pin box extensions and sliding fifth wheel hitch assemblies can help this condition. There should be at least six inches of clearance between the top of the pickup box and the bottom of the trailer shelf that extends over the box. Make sure the hitch is attached to the tow vehicle frame rails. Do not use the pickup box for support.

Safety Chains You should always attach chains between your vehicle and your trailer. Cross the safety chains under the tongue of the trailer to help prevent the tongue from contacting the road if it becomes separated from the hitch. Instructions about safety chains may be provided by the hitch manufacturer or by the trailer manufacturer. If you are towing a trailer up to 5,000 lbs (2 271 kg) with a factory-installed step bumper, you may attach the safety chains to the attaching points on the bumper. If you are towing a trailer up to your vehicle’s trailer rating limit you may attach the safety chains to the attaching point on the hitch platform. If you are towing with an aftermarket hitch follow the trailer or hitch manufacturer’s recommendation for attaching safety chains. Always leave just enough slack so you can turn with your rig. Never allow safety chains to drag on the ground.

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Trailer Brakes If your trailer weighs more than 2,000 lbs (900 kg) loaded, then it needs its own brakes – and they must be adequate. Be sure to read and follow the instructions for the trailer brakes so you’ll be able to install, adjust and maintain them properly. Your trailer brake system can tap into the vehicle’s hydraulic brake system only if:

The trailer parts can withstand 3,000 psi (20 650 kPa) of pressure. The trailer’s brake system will use less than 0.02 cubic inch (0.3 cc) of fluid from your vehicle’s master cylinder. Otherwise, both braking systems won’t work well. You could even lose your brakes.

If everything checks out this far, make the brake tap at the port on the master cylinder that sends the fluid to the rear brakes. But don’t use copper tubing for this. If you do, it will bend and finally break off. Use steel brake tubing.

Driving with a Trailer

{CAUTION:

If you have a rear-most window open and you pull a trailer with your vehicle, carbon monoxide (CO) could come into your vehicle. You cannot see or smell CO. It can cause unconsciousness or death. See Engine Exhaust on page 2-57. To maximize your safety when towing a trailer: (cid:127) Have your exhaust system inspected for leaks, and make necessary repairs before starting on your trip.

(cid:127) Keep the rear-most windows closed.

If exhaust does come into your vehicle through a window in the rear or another opening, drive with your front, main heating or cooling system on and with the fan on any speed. This will bring fresh, outside air into your vehicle. Do not use the climate control setting for maximum air because it only recirculates the air inside your vehicle. See Climate Control System on page 3-21.

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(cid:127) (cid:127) (cid:127) Towing a trailer requires a certain amount of experience. Before setting out for the open road, you’ll want to get to know your rig. Acquaint yourself with the feel of handling and braking with the added weight of the trailer. And always keep in mind that the vehicle you are driving is now a good deal longer and not nearly as responsive as your vehicle is by itself. Before you start, check all trailer hitch parts and attachments, safety chains, electrical connector, lamps, tires and mirror adjustment. If the trailer has electric brakes, start your vehicle and trailer moving and then apply the trailer brake controller by hand to be sure the brakes are working. This lets you check your electrical connection at the same time. During your trip, check occasionally to be sure that the load is secure, and that the lamps and any trailer brakes are still working. While towing a trailer or when exposed to long periods of sunshine, the floor of the truck bed may become very warm. Avoid putting items in the truck bed that might be affected by high ambient temperatures.

Following Distance Stay at least twice as far behind the vehicle ahead as you would when driving your vehicle without a trailer. This can help you avoid situations that require heavy braking and sudden turns. Passing You’ll need more passing distance up ahead when you’re towing a trailer. And, because you’re a good deal longer, you’ll need to go much farther beyond the passed vehicle before you can return to your lane. Backing Up Hold the bottom of the steering wheel with one hand. Then, to move the trailer to the left, just move that hand to the left. To move the trailer to the right, move your hand to the right. Always back up slowly and, if possible, have someone guide you.

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Making Turns Notice: Making very sharp turns while trailering could cause the trailer to come in contact with the vehicle. Your vehicle could be damaged. Avoid making very sharp turns while trailering. When you’re turning with a trailer, make wider turns than normal. Do this so your trailer won’t strike soft shoulders, curbs, road signs, trees or other objects. Avoid jerky or sudden maneuvers. Signal well in advance. Turn Signals When Towing a Trailer The arrows on your instrument panel will flash whenever you signal a turn or lane change. Properly hooked up, the trailer lamps will also flash, telling other drivers you’re about to turn, change lanes or stop. When towing a trailer, the arrows on your instrument panel will flash for turns even if the bulbs on the trailer are burned out. Thus, you may think drivers behind you are seeing your signal when they are not. It’s important to check occasionally to be sure the trailer bulbs are still working. Driving On Grades Reduce speed and shift to a lower gear before you start down a long or steep downgrade. If you don’t shift down, you might have to use your brakes so much that they would get hot and no longer work well.

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If you have an automatic transmission, you can tow in DRIVE (D). You may want to shift the transmission to a lower gear selection if the transmission shifts too often (e.g., under heavy loads and/or hilly conditions). You may also want to activate the tow/haul mode if the transmission shifts too often. See Tow/Haul Mode Light on page 3-50. If you have a 5-speed manual transmission and you are towing a trailer, it’s better not to use FIFTH (5) gear. Just drive in FOURTH (4) gear (or, as you need to, a lower gear). If you have a 6-speed manual transmission and you are towing a trailer, it’s better not to use SIXTH (6) gear. Drive in FIFTH (5) gear (or, as you need to, a lower gear). When towing at high altitude on steep uphill grades, consider the following: Engine coolant at or near sea level will boil at a lower temperature than at higher altitudes. If you turn your engine off immediately after towing at high altitude on steep uphill grades, your vehicle may show signs similar to engine overheating. To avoid this, let the engine run while parked, preferably on level ground, with the automatic transmission in PARK (P) for at least five minutes before turning the engine off. For manual transmissions, let the engine run while parked, preferably on level ground, with the transmission out of gear and the parking brake applied, for at least five minutes before turning the engine off. If you do get the overheat warning, see Engine Overheating on page 5-37.

Parking on Hills

{CAUTION:

You really should not park your vehicle, with a trailer attached, on a hill. If something goes wrong, your rig could start to move. People can be injured, and both your vehicle and the trailer can be damaged.

But if you ever have to park your rig on a hill, here’s how to do it: 1. Apply your regular brakes, but don’t shift into PARK (P) yet for an automatic transmission, or into gear for a manual transmission.

2. Have someone place chocks under the trailer

wheels.

3. When the wheel chocks are in place, release the regular brakes until the chocks absorb the load.

4. Reapply the regular brakes. Then apply your parking brake and shift into PARK (P) for an automatic transmission, or REVERSE (R) for a manual transmission.

{CAUTION:

It can be dangerous to get out of your vehicle if the shift lever is not fully in PARK (P) 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 will not move, even when you are on fairly level ground, use the steps that follow. Always put the shift lever fully in PARK (P) with the parking brake firmly set. If the transfer case on four-wheel-drive vehicles is in NEUTRAL, your vehicle will be free to roll, even if your shift lever is in PARK (P). So, be sure the transfer case is in a drive gear — not in NEUTRAL.

5. If you have a four-wheel-drive vehicle, be sure the

transfer case is in a drive gear and not in NEUTRAL.

6. Release the regular brakes.

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When You Are Ready to Leave After Parking on a Hill 1. Apply your regular brakes and hold the pedal down

while you: (cid:127) Start your engine (cid:127) Shift into a gear (cid:127) Release the parking brake

2. Let up on the brake pedal. 3. Drive slowly until the trailer is clear of the chocks. 4. Stop and have someone pick up and store the

chocks.

Maintenance When Trailer Towing Your vehicle will need service more often when you’re pulling a trailer. See Scheduled Maintenance (Gasoline Engine) on page 6-4 for more information. Things that are especially important in trailer operation are automatic transmission fluid (don’t overfill), engine oil, axle lubricant, belt, cooling system and brake system. Each of these is covered in this manual, and the Index will help you find them quickly. If you’re trailering, it’s a good idea to review these sections before you start your trip. Check periodically to see that all hitch nuts and bolts are tight.

4-92

Trailer Wiring Harness Your vehicle is equipped with one of the following wiring harnesses for towing a trailer or hauling a slide-in camper. Basic Trailer Wiring All regular, extended cab and crew cab pickups have an eight-wire trailer towing harness.

For vehicles not equipped with heavy duty trailering, the harness is clipped to the vehicle’s frame behind the spare tire mount. The harness requires the installation of a trailer connector, which is available through your dealer.

If your trailer is equipped with electric brakes, you can get a jumper harness (electric trailer brake control) with a trailer battery feed fuse from your dealer. If you need to tow a light-duty trailer with a standard four-way round pin connector, you can also get an adapter form your dealer. Heavy-DutyTrailer Wiring Harness Package

The eight-wire harness contains the following trailer circuits: (cid:127) Yellow: Left Stop/Turn Signal (cid:127) Dark Green: Right Stop/Turn Signal (cid:127) Brown: Taillamps (cid:127) White: Ground

Light Green: Back-up Lamps Light Blue: CHMSL* (cid:127) Red: Battery Feed** (cid:127) Dark Blue: Trailer Brake * The Center High-Mounted Stoplamp (CHMSL) wire is tied next to the trailer wiring harness for use with a trailer, slide-in camper or cap. **If you are charging a remote (non-vehicle) battery, turn on the headlamps to boost the vehicle system voltage and properly charge the battery.

For vehicles equipped with heavy duty trailering, the harness is connected to the trailer plug mounted to the hitch platform.

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(cid:127) (cid:127) Camper/Fifth-Wheel Trailer Wiring Package The eight-wire camper harness is located under the front edge of the pickup box on the driver’s side of the vehicle, attached to the frame bracket. A connector will have to be added to the wiring harness which connects to the camper. The eight-wire harness contains the following camper/trailer circuits: (cid:127) Yellow: Left Stop/Turn Signal (cid:127) Dark Green: Right Stop/Turn Signal (cid:127) Brown: Taillamps (cid:127) White: Ground

Light Green: Back-up Lamps Light Blue: Center High-Mounted Stoplamp (CHMSL) (cid:127) Red: Battery Feed (cid:127) Dark Blue: Trailer Brake

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If your vehicle is equipped with the “Heavy-Duty Trailering” option, please refer to “Heavy-Duty Trailer Wiring Package” earlier in this section. When the camper-wiring harness is ordered without the heavy-duty trailering package, an eight-wire harness with a seven-pin connector and separate CHMSL connector are located at the rear of the vehicle and are tied to the vehicle’s frame.

(cid:127) (cid:127) Electric Brake Control Jumper

{CAUTION:

Be sure to use only the correct trailer brake harness, the one intended for use on your vehicle. If you use some other trailer brake harness, even if it seems to fit, your trailer brakes may not work at all. You could have a crash in which you or others could be injured. Use only the trailer brake harness intended for your vehicle. If it is no longer available to you, be sure to get a proper replacement from your dealer.

This harness is included with your vehicle as part of the heavy-duty trailer wiring package. This harness is for an electric brake controller and includes a trailer battery feed fuse. It should be installed by your dealer or a qualified service center.

4-95

Auxiliary Battery The auxiliary battery provision can be used to supply electrical power to additional equipment that you may choose to add, such as a slide-in camper.

If your vehicle has this provision, this relay will be located on the passenger’s side of the vehicle, next to the auxiliary battery.

When using this provision, connection should only be made to the upper stud (A) of the relay. Do not make connections to the lower stud (B) of the relay. The auxiliary battery circuit is protected by a megafuse located behind the auxiliary battery. Be sure to follow the proper installation instructions that are included with any electrical equipment that you install.

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Notice: Leaving electrical equipment on for extended periods will drain the battery. Always turn off electrical equipment when not in use and do not use equipment that exceeds the maximum amperage rating for the auxiliary battery provision. Power Winches If you wish to use a power winch on your vehicle, only use it when your vehicle is stationary or anchored.

Trailer Recommendations You must subtract your hitch loads from the CWR for your vehicle. Weigh your vehicle with the trailer attached, so that you won’t go over the GVWR or GAWR. If you are using a weight-distributing hitch, weigh the vehicle without the spring bars in place. You’ll get the best performance if you spread out the weight of your load the right way, and if you choose the correct hitch and trailer brakes. For more information, see Towing a Trailer on page 4-67.

Power Take-Off (PTO) Before using a Power Take-Off (PTO), if equipped, refer to the manufacturer’s or installer’s instructions. To engage a PTO on a vehicle with a manual transmission do the following: 1. Hold the clutch pedal down. 2. Set the parking brake. 3. Shift the transmission into NEUTRAL. 4. Engage the PTO. Refer to the manufacturer’s or installer’s for instructions on electrically engaged PTOs.

5. For mobile operations, shift the transmission into the gear you want, apply the regular brakes and release the parking brake. For stationary operations, leave the parking brake applied.

6. Release the clutch and regular brakes as you normally would. When the clutch is released, the PTO will start.

7. Turn the PTO rotary switch to ON.

To engage a PTO on a vehicle with an automatic transmission do the following: 1. For stationary use shift the transmission into

PARK (P).

2. Turn the PTO rotary switch ON. 3. If the engine speed is below the PTO engage speed limit, the PTO will start. The blinking LED on the PTO control switch indicates PTO engage is requested. When PTO engages the LED will switch from blinking to a steady light.

To use PTO speed control in Preset Mode (Factory Setting) do the following: 1. Engage the PTO. 2. Select PARK (P) or NEUTRAL (N) range. Apply

the parking brake if NEUTRAL (N) is selected. Torque Converter Clutch (TCC) is not available in NEUTRAL (N) and is available only in PARK (P) when engine speed is above 1,100 rpm.

3. Make sure your foot is off the brake pedal (and

off the clutch on vehicles equipped with a manual transmission).

4. Select the desired engine speed for PTO operation.

Read the following preset mode information regarding operation.

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Preset Mode: PTO speed control mode is used for stationary applications. (PTO will remain engaged while mobile in the preset mode, however PTO set and resume speed controls will be inoperative.) This mode provides a default standby speed of 800 or 850 rpm (depending on the engine/transmission combination) and two default PTO control speeds which follow: 1. PTO Set Speed of 1,250 rpm, or 2. PTO Resume Speed of 1,700 rpm. Please note that the standby speed (800/850 rpm) is not to be used as a PTO control speed. Vehicles not equipped with cruise control will not have the resume speed capability. To use PTO speed control in variable mode (while mobile) do the following: 1. Engage the PTO. 2. Vehicle speed must be greater than 5 mph. 3. Make sure your foot is off the brake pedal (and

off the clutch for vehicles equipped with a manual transmission).

4. Select the desired engine speed by using the foot

pedal, and select SET on the PTO switch or the cruise control.

To use PTO speed control in variable mode (while stationary) do the following: 1. Engage the PTO. 2. Vehicle speed must be less than 5 mph. 3. Make sure your foot is off the brake pedal (and

off the clutch for vehicles equipped with a manual transmission).

4. Select the desired engine speed by using the foot

pedal, and select SET on the PTO switch or the cruise control.

Variable Mode: PTO speed control mode can be used for both stationary and mobile applications. This mode allows PTO to be controlled in a fashion similar to how cruise control sets vehicle speed. The operator can set to an rpm (between 800 and 2,200) with the cruise control feature or with the SET position on the PTO switch. The operator is then able to increase rpm in increments of 100, or “tap up” with the resume position on the cruise control. The operator can also decrease rpm in increments of 100 with the SET switch on the PTO or the cruise control. Vehicles not equipped with cruise control will not have the “tap up” capability.

4-98

All engine speed values listed above are factory preset values. With the exception of the TCC lockup speed (1,100 rpm) and the “tap” increment (100 rpm), all of these values are programmable and can be adjusted by your dealer or body upfitter. If the PTO software settings do not match the settings shown here, then they may have already been altered in order to satisfy the requirements of the installed PTO system and body equipment. When the PTO switch is turned on, the engine is limited to 2,200 rpms. If there are no accessories installed on the vehicle, make sure the PTO switch is turned off.

Step-Bumper Pad Your vehicle has a rear step bumper with a rear step pad at the center of the bumper.

If you will be using the bumper to tow a trailer, and your step-bumper has three cutout circles, you must push out the center cutout circle to install the trailer ball.

If your step-bumper has only one cutout circle, you will have to cut out the circle, then remove it to install the trailer ball.

4-99

✍ NOTES

4-100

Section 5

Service and Appearance Care

Service ............................................................5-4
Accessories and Modifications ..........................5-4
California Proposition 65 Warning .....................5-4
Doing Your Own Service Work .........................5-5
Adding Equipment to the Outside of

Your Vehicle ..............................................5-5
Fuel ................................................................5-5
Gasoline Octane ............................................5-6
Gasoline Specifications ....................................5-6
California Fuel ...............................................5-7
Additives .......................................................5-7
Fuel E85 (85% Ethanol) ..................................5-8
Fuels in Foreign Countries ...............................5-9
Filling the Tank ............................................5-10
Filling a Portable Fuel Container .....................5-11
Checking Things Under the Hood ....................5-12
Hood Release ..............................................5-13
Engine Compartment Overview .......................5-14
Engine Oil (Gasoline Engine) ..........................5-20
Engine Oil Life System (Gasoline Engine) ........5-23
Engine Air Cleaner/Filter (Gasoline Engines) .......5-25
Automatic Transmission Fluid

(Except Allison Transmission®) ....................5-28

Automatic Transmission Fluid

(Allison Transmission®) ...............................5-30
Manual Transmission Fluid .............................5-33
Hydraulic Clutch ...........................................5-34
Engine Coolant .............................................5-35
Coolant Surge Tank Pressure Cap ..................5-37
Engine Overheating .......................................5-37
Overheated Engine Protection Operating Mode

(V8 Engines Only) ......................................5-39
Cooling System ............................................5-40
Engine Fan Noise .........................................5-45
Power Steering Fluid .....................................5-45
Windshield Washer Fluid ................................5-46
Brakes ........................................................5-47
Battery ........................................................5-51
Jump Starting ...............................................5-52
Rear Axle .......................................................5-58
Four-Wheel Drive ............................................5-59
Front Axle ......................................................5-60
Noise Control System .....................................5-62

Tampering with Noise Control System

Prohibited .................................................5-62

5-1

Section 5

Service and Appearance Care

Bulb Replacement ..........................................5-63
Halogen Bulbs ..............................................5-63
Headlamps ..................................................5-63
Front Turn Signal, Sidemarker and

Daytime Running Lamps .............................5-64
Roof Marker Lamps ......................................5-66
Center High-Mounted Stoplamp (CHMSL)

and Cargo Lamp ........................................5-67

Pickup Box Identification and Fender

Marker Lamps ...........................................5-68

Taillamps, Turn Signal, Stoplamps and

Back-up Lamps .........................................5-68
Replacement Bulbs .......................................5-70
Windshield Wiper Blade Replacement ..............5-71
Tires ..............................................................5-72
Tire Sidewall Labeling ...................................5-73
Tire Terminology and Definitions .....................5-76
Inflation - Tire Pressure .................................5-79
Dual Tire Operation .......................................5-80
Tire Inspection and Rotation ...........................5-81
When It Is Time for New Tires .......................5-83
Buying New Tires .........................................5-84
Different Size Tires and Wheels ......................5-85

Uniform Tire Quality Grading ..........................5-86
Wheel Alignment and Tire Balance ..................5-87
Wheel Replacement ......................................5-87
Tire Chains ..................................................5-89
If a Tire Goes Flat ........................................5-90
Changing a Flat Tire .....................................5-91
Removing the Spare Tire and Tools ................5-92
Removing the Flat Tire and Installing the

Spare Tire ................................................5-96
Secondary Latch System ..............................5-105
Storing a Flat or Spare Tire and Tools ...........5-108
Spare Tire .................................................5-112
Appearance Care ..........................................5-113
Cleaning the Inside of Your Vehicle ...............5-113
Fabric/Carpet ..............................................5-114
Leather ......................................................5-115
Instrument Panel, Vinyl, and

Other Plastic Surfaces ..............................5-115
Care of Safety Belts ....................................5-116
Weatherstrips .............................................5-116
Washing Your Vehicle ..................................5-116
Cleaning Exterior Lamps/Lenses ....................5-117
Finish Care ................................................5-117

5-2

Section 5

Service and Appearance Care

Windshield and Wiper Blades .......................5-118
Aluminum or Chrome-Plated Wheels ..............5-118
Tires .........................................................5-119
Sheet Metal Damage ...................................5-119
Finish Damage ...........................................5-120
Underbody Maintenance ...............................5-120
Chemical Paint Spotting ...............................5-120
Vehicle Care/Appearance Materials ................5-121
Vehicle Identification .....................................5-122
Vehicle Identification Number (VIN) ................5-122
Service Parts Identification Label ...................5-122

Electrical System ..........................................5-123
Add-On Electrical Equipment .........................5-123
Windshield Wiper Fuses ...............................5-123
Power Windows and Other Power Options ......5-123
Fuses and Circuit Breakers ..........................5-123
Instrument Panel Fuse Block ........................5-124
Center Instrument Panel Fuse Block ..............5-126
Underhood Fuse Block ................................5-127
Capacities and Specifications ........................5-133

5-3

Service Your dealer knows your vehicle best and wants you to be happy with it. We hope you will go to your dealer for all your service needs. You will get genuine GM parts and GM-trained and supported service people. We hope you will want to keep your GM vehicle all GM. Genuine GM parts have one of these marks:

Accessories and Modifications When you add non-GM accessories to your vehicle they can affect your vehicle’s performance and safety, including such things as, braking, stability, ride and handling, emissions systems, aerodynamics, durability, and electronic systems like antilock brakes, traction control and stability control. Some of these accessories may even cause malfunction or damage not covered by warranty. GM Accessories are designed to complement and function with other systems on your vehicle. Your GM dealer can accessorize your vehicle using genuine GM Accessories. When you go to your GM dealer and ask for GM Accessories, you will know that GM-trained and supported service technicians will perform the work using genuine GM Accessories.

California Proposition 65 Warning Most motor vehicles, including this one, contain and/or emit chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. Engine exhaust, many parts and systems (including some inside the vehicle), many fluids, and some component wear by-products contain and/or emit these chemicals.

5-4

Doing Your Own Service Work

{CAUTION:

You can be injured and your vehicle could be damaged if you try to do service work on a vehicle without knowing enough about it.

(cid:127) Be sure you have sufficient knowledge,

experience, the proper replacement parts, and tools before you attempt any vehicle maintenance task.

(cid:127) Be sure to use the proper nuts, bolts,

and other fasteners. English and metric fasteners can be easily confused. If you use the wrong fasteners, parts can later break or fall off. You could be hurt.

If you want to do some of your own service work, you will want to use the proper service manual. It tells you much more about how to service your vehicle than this manual can. To order the proper service manual, see Service Publications Ordering Information on page 7-15.

Your vehicle has an airbag system. Before attempting to do your own service work, see Servicing Your Airbag-Equipped Vehicle on page 1-86. You should keep a record with all parts receipts and list the mileage and the date of any service work you perform. See Maintenance Record on page 6-20.

Adding Equipment to the Outside of Your Vehicle Things you might add to the outside of your vehicle can affect the airflow around it. This may cause wind noise and affect windshield washer performance. Check with your dealer before adding equipment to the outside of your vehicle. Fuel If your vehicle has a diesel engine, see “Diesel Fuel Requirements and Fuel System” in the DURAMAX® Diesel Supplement. For vehicles with gasoline engines, please read this.

5-5

Gasoline The 8th digit of your vehicle identification number (VIN) shows the code letter or number that identifies your engine. You will find the VIN at the top left of the instrument panel. See Vehicle Identification Number (VIN) on page 5-122. If your vehicle has the 5.3L V8 engine (VIN Code Z), you may use either regular unleaded gasoline or ethanol fuel containing up to 85% ethanol (E85); also see Fuel E85 (85% Ethanol) on page 5-8. In all other gasoline engines, use only regular unleaded gasoline.

Gasoline Octane For all vehicles, except those with the 6.0L V8 engine (VIN Code N), use regular unleaded gasoline with a posted octane rating of 87 or higher. If the octane rating is less than 87, you may notice an audible knocking noise when you drive, commonly referred to as spark knock. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. If you are using gasoline rated at 87 octane or higher and you hear heavy knocking, your engine needs service.

If your vehicle has the 6.0L V8 engine (VIN Code N), use premium unleaded gasoline with a posted octane rating of 91 or higher. You may also use regular unleaded gasoline rated at 87 octane or higher, but your vehicle’s acceleration may be slightly reduced, and you may notice a slight audible knocking noise, commonly referred to as spark knock. If the octane is less than 87, you may notice a heavy knocking noise when you drive. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. Otherwise, you might damage your engine. If you are using gasoline rated at 87 octane or higher and you hear heavy knocking, your engine needs service.

Gasoline Specifications At a minimum, gasoline should meet ASTM specification D 4814 in the United States or CAN/CGSB-3.5 in Canada. Some gasolines may contain an octane-enhancing additive called methylcyclopentadienyl manganese tricarbonyl (MMT). General Motors recommends against the use of gasolines containing MMT. See Additives on page 5-7
for additional information.

5-6

California Fuel If your vehicle is certified to meet California Emissions Standards, it is designed to operate on fuels that meet California specifications. See the underhood emission control label. If this fuel is not available in states adopting California emissions standards, your vehicle will operate satisfactorily on fuels meeting federal specifications, but emission control system performance may be affected. The malfunction indicator lamp may turn on and your vehicle may fail a smog-check test. See Malfunction Indicator Lamp on page 3-46. If this occurs, return to your authorized GM dealer for diagnosis. If it is determined that the condition is caused by the type of fuel used, repairs may not be covered by your warranty.

Additives To provide cleaner air, all gasolines in the United States are now required to contain additives that will help prevent engine and fuel system deposits from forming, allowing your emission control system to work properly. In most cases, you should not have to add anything to your fuel. However, some gasolines contain only the minimum amount of additive required to meet U.S. Environmental Protection Agency regulations. To help keep fuel injectors and intake valves clean, or if your vehicle experiences problems due to dirty injectors or valves, look for gasoline that is advertised as TOP TIER Detergent Gasoline. Also, your GM dealer has additives that will help correct and prevent most deposit-related problems.

5-7

Gasolines containing oxygenates, such as ethers and ethanol, and reformulated gasolines may be available in your area. General Motors recommends that you use these gasolines if they comply with the specifications described earlier. However, E85 (85% ethanol) and other fuels containing more than 10% ethanol must not be used in vehicles that were not designed for those fuels. Notice: Your vehicle was not designed for fuel that contains methanol. Do not use fuel containing methanol. It can corrode metal parts in your fuel system and also damage the plastic and rubber parts. That damage would not be covered under your warranty. Some gasolines that are not reformulated for low emissions may contain an octane-enhancing additive called methylcyclopentadienyl manganese tricarbonyl (MMT); ask the attendant where you buy gasoline whether the fuel contains MMT. General Motors recommends against the use of such gasolines. Fuels containing MMT can reduce the life of spark plugs and the performance of the emission control system may be affected. The malfunction indicator lamp may turn on. If this occurs, return to your authorized GM dealer for service.

5-8

Fuel E85 (85% Ethanol) The 8th digit of your vehicle identification number (VIN) shows the code letter or number that identifies your engine. You will find the VIN at the top left of the instrument panel. See Vehicle Identification Number (VIN) on page 5-122. If your vehicle has the 5.3L V8 engine (VIN Code Z only), you may use either regular unleaded gasoline or ethanol fuel containing up to 85% ethanol (E85); also see Fuel on page 5-5. In all other engines, including the 5.3L V8 (VIN Code T), use only regular unleaded gasoline. Only vehicles that have the 5.3L V8 engine (VIN Code Z) may use 85% ethanol fuel (E85). General Motors encourages the use of E85 in vehicles that are designed to use it. The ethanol in E85 is a “renewable” fuel, meaning it is made from renewable sources such as corn and other crops. Many service stations will not have an 85% ethanol fuel (E85) pump available. The U. S. Department of Energy has an alternative fuels website (http://www.eere.energy.gov/afdc/infrastructure/ locator.html) that can help you find E85 fuel. Those stations that do have E85 should have a label indicating ethanol content. Do not use the fuel if the ethanol content is greater than 85%. At a minimum, E85 should meet ASTM Specification D 5798.

To ensure quick starts in the wintertime, the E85 fuel must be formulated properly for your climate according to ASTM specification D 5798. If you have trouble starting on E85, it may be because your E85 fuel is not properly formulated for your climate. If this happens, switching to gasoline or adding gasoline to your fuel tank may improve starting. Your vehicle is designed to accommodate a mixture of gasoline and E85 fuel. For good starting and heater efficiency below 32°F (0°C), the fuel mix in the fuel tank should contain no more than 70% ethanol. E85 has less energy per gallon than gasoline, so you will need to refill your fuel tank more often when using E85
than when you are using gasoline. Regular unleaded gasoline is recommended when pulling a trailer. For payload capacity with ethanol fuel, see Loading Your Vehicle on page 4-48. Notice: Some additives are not compatible with E85
fuel and may harm your fuel system. Damage caused by additives would not be covered by your new vehicle warranty. Do not use additives with E85 fuel.

Notice: Your vehicle was not designed for fuel that contains methanol. Do not use fuel containing methanol. It can corrode metal parts in your fuel system and also damage the plastic and rubber parts. That damage would not be covered under your warranty.

Fuels in Foreign Countries If you plan on driving in another country outside the United States or Canada, the proper fuel may be hard to find. Never use leaded gasoline or any other fuel not recommended in the previous text on fuel. Costly repairs caused by use of improper fuel would not be covered by your warranty. To check the fuel availability, ask an auto club, or contact a major oil company that does business in the country where you will be driving.

5-9

{CAUTION:

If you spill fuel and then something ignites it, you could be badly burned. Fuel can spray out on you if you open the fuel cap too quickly. This spray can happen if your tank is nearly full, and is more likely in hot weather. Open the fuel cap slowly and wait for any hiss noise to stop. Then unscrew the cap all the way.

If your vehicle is a dual fuel tank chassis cab model, and it runs out of fuel, refuel the front fuel tank first to ensure a quick restart. Be careful not to spill fuel. Do not top off or overfill the tank and wait a few seconds after you have finished pumping before removing the nozzle. Clean fuel from painted surfaces as soon as possible. See Washing Your Vehicle on page 5-116.

Filling the Tank

{CAUTION:

Fuel vapor burns violently and a fuel fire can cause bad injuries. To help avoid injuries to you and others, read and follow all the instructions on the pump island. Turn off your engine when you are refueling. Do not smoke if you are near fuel or refueling your vehicle. Keep sparks, flames, and smoking materials away from fuel. Do not leave the fuel pump unattended when refueling your vehicle — this is against the law in some places. Keep children away from the fuel pump; never let children pump fuel.

The tethered fuel cap is located behind a hinged fuel door on the driver’s side of the vehicle. To remove the fuel cap, turn it slowly counterclockwise. It will require more effort to turn the fuel cap on the last turn as you loosen it.

5-10

When replacing the fuel cap, turn it clockwise until it clicks. It will require more effort to turn the fuel cap on the last turn as you tighten it. Make sure the cap is fully installed. The diagnostic system can determine if the fuel cap has been left off or improperly installed. This would allow fuel to evaporate into the atmosphere. See Malfunction Indicator Lamp on page 3-46. The TIGHTEN FUEL CAP message will be displayed on the Driver Information Center (DIC) if the fuel cap is not properly installed. See DIC Warnings and Messages on page 3-55 for more information.

{CAUTION:

If a fire starts while you are refueling, do not remove the nozzle. Shut off the flow of fuel by shutting off the pump or by notifying the station attendant. Leave the area immediately.

Notice: If you need a new fuel cap, be sure to get the right type. Your dealer can get one for you. If you get the wrong type, it may not fit properly. This may cause your malfunction indicator lamp to light and may damage your fuel tank and emissions system. See Malfunction Indicator Lamp on page 3-46.

Filling a Portable Fuel Container

{CAUTION:

Never fill a portable fuel container while it is in your vehicle. Static electricity discharge from the container can ignite the gasoline vapor. You can be badly burned and your vehicle damaged if this occurs. To help avoid injury to you and others:

(cid:127) Dispense gasoline only into approved

containers.

(cid:127) Do not fill a container while it is inside a vehicle, in a vehicle’s trunk, pickup bed, or on any surface other than the ground.

(cid:127) Bring the fill nozzle in contact with the

inside of the fill opening before operating the nozzle. Contact should be maintained until the filling is complete.

(cid:127) Do not smoke while pumping gasoline.

5-11

Checking Things Under the Hood

{CAUTION:

An electric fan under the hood can start up and injure you even when the engine is not running. Keep hands, clothing and tools away from any underhood electric fan.

{CAUTION:

Things that burn can get on hot engine parts and start a fire. These include liquids like fuel, oil, coolant, brake fluid, windshield washer and other fluids, and plastic or rubber. You or others could be burned. Be careful not to drop or spill things that will burn onto a hot engine.

5-12

Hood Release To open the hood do the following:

1. Pull the handle with this symbol on it. It is located inside the vehicle to the lower left of the steering wheel.

2. Then go to the front of the vehicle and pull up on the

secondary hood release located near the center of the grille.

3. Lift the hood.

Before closing the hood, be sure all the filler caps are on properly. Then pull down the hood and close it firmly.

5-13

Engine Compartment Overview When you open the hood on the 4.3L V6 engine, here is what you will see:

5-14

A. Engine Air Cleaner/Filter. See Engine Air

Cleaner/Filter (Gasoline Engines) on page 5-25.

B. Coolant Surge Tank and Pressure Cap. See Engine

Coolant on page 5-35 and Coolant Surge Tank Pressure Cap on page 5-37.

C. Air Filter Restriction Indicator (If Equipped).

See Engine Air Cleaner/Filter (Gasoline Engines) on page 5-25.

D. Engine Oil Dipstick. See “Checking Engine Oil”

under Engine Oil (Gasoline Engine) on page 5-20.

E. Automatic Transmission Fluid Dipstick (If Equipped).

See “Checking the Fluid Level” under Automatic Transmission Fluid (Except Allison Transmission®) on page 5-28 or Automatic Transmission Fluid (Allison Transmission®) on page 5-30.

F. Engine Cooling Fan. See Cooling System on

page 5-40.

G. Engine Oil Fill Cap. See “When to Add Engine Oil” under Engine Oil (Gasoline Engine) on page 5-20.

H. Power Steering Fluid Reservoir. See Power Steering

Fluid on page 5-45.

I. Remote Negative (−) Terminal (GND). See Jump

Starting on page 5-52.

J. Remote Positive (+) Terminal. See Jump Starting on

page 5-52.

K. Brake Fluid Reservoir. See “Brake Fluid” under

Brakes on page 5-47.

L. Clutch Fluid Reservoir (If Equipped). See Hydraulic

Clutch on page 5-34.

M. Underhood Fuse Block. See Underhood Fuse Block