1996 GMC Sierra Owners Manual

4.10

4.56

10,500 lbs.* (4 767 kg) 12,500 lbs.* (5 675 kg)

*Fifth wheel hitch rating; weight distributing hitch rating is limited to 10,000 lbs. (4 540 kg).

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C-3500 Crew Cab (2WD) Engine (Trans.) Axle 5.7L

K-3500 Crew Cab (4WD) Engine (Tkans.) Axle 5.7L

4.10

Ratio Max. Trailer Wt.

4.10 4.56 4.10

7,500 lbs. (3 405 kg) 9,000 Ibs. (4 086 kg) 8,000 lbs. (3 632 kg)

4.10

7,000 Ibs. (3 178 kg)

4.10

4.56

10,500 lbs.* (4 767 kg) 12,500 Ibs.* (5 675 kg)

6% Diesel

(Auto.)

6.5L Diesel (Manual)

7.4L

Ratio Max. Trailer Wt.

4.56 8,500 4.10

7,000 Ibs. (3 178 kg) Ibs. (3 859 kg) 8,000 Ibs. (3 632 kg)

4.10

7,000 Ibs. (3 178 kg)

4.10

4.56

10,500 Ibs* (4 767 kg) 12,500 Ibs? (5 675 kg)

6.5L Diesel

(Auto.)

6.5L Diesel (Manual)

7.4L

*Fifth wheel hitch rating.; weight distributing hitch rating is limited to 10,000 lbs. (4 540 kg).

*Fifth wheel hitch rating; weight distributing hitch rating is limited to 10,000 Ibs. (4 540 kg).

4-52

(2-3500 HDiChassis .Cab Engine (Trans.) Axle 5.7L

Ratio Max. Trailer Wt.

6% Diesel

(Auto.)

6.5L Diesel (Manual)

7.4L

4.63 5.13 4.63 5.13

4.63 5.13 4.63

5.13

(3

8,500 lbs. kg) 859 8,500 lbs. (3 859 kg) 8,000 lbs. (3 632 kg) 10,500 lbs.* (4 767 kg) 7,000 lbs. (3 178 kg) 8,500 lbs. (3 859 kg) 12,500 lbs.* (5 675 kg) 12,500 lbs.* (5 675 kg)

*Fifth wheel hitch rating; weight distributing hitch rating is limited to 10,000 lbs. (4 540 kg).

You can ask your dealer for our trailering information or advice, or you can write us at the addreis listed in your Warranty and Owner Assistance Information Booklet. In Canada, write to:

General Motors of Canada Limited Customer Assistance Center 1908 Colonel Sam Drive Oshawa, Ontario LlH 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. 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. S&e “Loading Your Vehicle” in the Index for more information about your vehicle’s maximum load capacity.

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Total Weight on Your Vehicle’s Tires Be sure your vehicle’s tires are inflated to the limit for cold tires. You’ll find these numbers on the Certification label at the rear edge of the driver’s door or see “Tire Loading” in the Index. Then be sure you don’t go over the GVW limit for your vehicle, including the weight of the trailer tongue. 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. Here are some rules to follow:

If you use a step-bumper hitch, your bumper could be damaged in sharp turns. Make sure you have ample room when turning to avoid contact between the trailer and the bumper.

0 If you’ll be pulling a trailer that, when loaded, will

weigh more than 4,000 Ibs. (1 800 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 you’re driving.

If you’re using a weight-carryipg hitch, the trailer tongue (A) should weigh 10 percent of the total loaded trailer weight (B). If you’re using a weight-distributing hitch, the trailer tongue (A) should weigh 12 percent of the total loaded trailer weight (B). After you’ve loaded your trailer, weigh the trailer and then the tongue, separately, to see if the weights are proper. If they aren’t, you may be able to get them right simply by moving some items around in the trailer.

Y

You should always attach chains between your vehicle and your trailer. Cross the safety chains under the tongue of the trailer so that the tongue will not drop to 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. Follow the manufacturer’s recommendation for attaching safety chains and do not attach them to the bumper. Always leave just enough slack so you can turn with your rig. And, never allow safety chains to drag on the ground.

If your trarler weighs more than 1,000 lbs. (450 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.

0 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.

rrailer

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 the trailer hitch and platform (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.

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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 slowlv and. if possible, have someone guide you.

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.

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Turn Signals When Towing a Trailer The green 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 green 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 b e ~ m 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. On a long uphill grade, shift down and reduce your speed to around 45 mph (70 km/h) to reduce the possibility of engine and transmission overheating.

If you have an automatic transmission, you should use THIRD (3) (or, as you need to, a lower gear) when towing a trailer. Operating your vehicle in THIRD (3) when towing a trailer will minimize heat build-up and extend the life of your transmission If you have a 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). When towing at high altitude on steep uphill grades, consider the following: Engine coolant will boil at a lower temperature than at normal 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) (or the manual transmission out of gear and the parking brake applied) for a few minutes before turning the engine off. If you do get the overheat warning, see “Engine Overheating’’ in the Index.

Parking on Hills 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. Have someone place chocks under the trailer wheels. When the wheel chocks are in place, release the regular brakes until the chocks absorb the load. 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. If you have a four-wheel-drive vehicle, be sure the transfer case is in a drive gear and not in NEUTRAL (N). Release the regular brakes.

2. 3.

4.

5.

6.

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 won’t move, even when you’re on fairly level ground, use the steps that follow. If you have four-wheel drive and your transfer case is in NEUTRAL (N), 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 (N).

Trailer Wiring Harness A seven-wire harness is stored under the rear end of your vehicle. between the frame rails. An electrical connector will need to be installed at the trailer end of the harness, by a qualified electrical technician. For additional trailer wiring and towing information please consult your GM dealer. Securely attach the harness to the trailer, then tape or strap it to your vehicle’s frame rail. Be sure you leave it loose enough so the wiring won’t bind or break when turning with the trailer, but not so loose that it drags on the ground. Store the harness in its original position. Wrap the harness together and tie it neatly so it won’t be damaged. If you tow a trailer, your Center High-Mounted Stoplamp (CHMSL) may not be properly visible from behind. You should select a trailer with a CHMSL on it or, if one is not available, have one installed. See your GM dealer about how to connect your vehicle’s wiring to a trailer CHMSL.

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

while you: 0 Start your engine;

Shift into a gear; and

0 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 the Maintenance Schedule for more on this. Things that are especially important in trailer operation are automatic transmission fluid (don’t overfill), engine oil, axle lubricant, belt, cooling system and brake adjustment. 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.

4-59

-

DW

* Winche-

Power Take-Off (PTO)

IT you wish to use a power winch on your vehicle, only use it when your vehicle is stationary or anchored.

NOTICE:

NOTICE:

Using a power winch with the transmission in gear may damage the transmission. When operating a power winch, always leave the transmission in NEUTRAL (N).

Use the regular brakes, set the parking brake, or block the wheels to keep your vehicle from rolling.

If you have a PTO that will exceed 35 hp installed on your vehicle, it could damage the transfer case or transmission. When having a PTO installed on your vehicle, make sure that it will not exceed 35 hp.

Before using a PTO, refer to the manufacturer’s or installer’s instructions.

I NOTICE:

Using a PTO while operating in one place before the vehicle has reached normal operating temperature can damage the transfer case or transmission. If you will be using the PTO while operating in one place, drive and warm up the vehicle before using the PTO.

Using a Transfer Case Mounted Power Take-Off (Manual Transmission) 1. Set the parking brake, 2. Shift the transfer case into NEUTRAL (N). 3. Hold the clutch pedal down. If the vehicle will

remain in the same place, shift the transmission into the highest gear. 4. Engage the PTO.

If you are going to drive the vehicle, shift the transmission into the gear you want. Then shift the transfer case into the range you want, apply the regular brakes and release the parking brake.

5. Release the clutch (and the regular brakes) as you nor~nally would. When you release the clutch, the PTO will start.

To engage a PTO: 1. Set the parking brake. 2. Shift the transmission into NEUTRAL (Nj. 3. Hold the clutch pedal down and engage the PTO.

NOTICE:

Using a PTO for more than four hours without driving your vehicle can damage the transfer case or transmission. If using a PTO for more than four hours without driving your vehicle, drive your vehicle for a while to allow the transfer case and transmission to cool.

If you are going to drive the vehicle, shift the transmission into the gear you want. Then shift the transfer case into the range you want (if you have four-wheel drive), apply the regular brakes and release the parking brake.

4. Release the clutch (and the regular brakes) as you normally would. When you release the clutch, the PTO will start.

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Using a Transfer Case Mounted Power Take-Off (Automatic Transmission) 1. 2. 3. 4.

Set the parking brake. Shift the transfer case into NEUTRAL (N). Shift the transmission into NEUTRAL (N). Engage the PTO. If you are going to drive the vehicle, shift the transfer case into the range yo11 want. Then apply the regular brakes and release the parking brake. Shift the transmission to THIRD (3) to start the PTO. Release the regular brakes to drive the vehicle.

5. 6. Step-Bumper Pad If your vehicle has a rear step bumper, it may be equipped with a rear step pad at the center of the bumper.

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If you will be using the bumper to tow a trailer, you must remove the center cutout circle to install the trailer ball. You must also remove both outer cutouts to attach the trailer safety chains.

To remove the pad, lift the edge of the pad from the rear of the bumper and swing it forward. When the pad releases from the bumper holes, lift the pad off.

Section 5 Problems on the Road

Here you’ll find what to do about some problems that can occur on the road. Hazard Warning Flashers

Your hazard warning flashers let you warn others. They also let police know you have a problem. Your front and rear turn signal lamps will flash on and off. But they won’t flash if you’re braking.

Press the button at the top of the steering column all the way down to make your front and rear turn signal lamps flash on and off.

Your hazard warning flashers work no matter what position your key is in, and even if the key isn’t in.

5-1

’ A CAUTION:

Batteries can hurt you. dangerous because:

They contain acid that can burn you. They contain gas that can explode or ignite. They contain enough electricity to burn you.

If you don’t follow these steps exactly, some or all of these things can hurt you.

1. Check the other vehicle. It must have a 12-volt

battery with a negative ground system.

I NOTICE:

If the other system isn’t a 12-volt system with a negative ground, both vehicles can be damaged.

To turn off the flashers, press the button until the first click and release. When the hazard warning flashers are on, your turn signals won’t work. Other Warning Devices If you carry reflective triangles, you can use them to warn others. Set one up at the side of the road about 300 feet (100 m) behind your vehicle. Jump Starting If your battery has run down, you may want to use another vehicle and some jumper cables to start your vehicle. But please use the following steps to do it safely.

NOTICE:

Ignoring these steps could result in costly damage to your vehicle that wouldn’t be covered by your vehicle warranty. Don’t try to start your vehicle by pushing or pulling it. This could damage your vehicle, even if you have a manual transmission. And if you have an automatic transmission, it won’t start that way.

5-2

2. Get the vehicles close enough so the jumper cables can reach, but be sure the ve.hicles aren’t touching each other. If they are, it could cause a ground connection you don’t want. You wouldn’t be able to start your vehicle, and the bad grounding could damage the electrical systems. To avoid the possibility of the vehicles rolling, set the parking brake firmly on both vehicles involved in the jump start procedure. Put an automatic transmission in PARK (P) or a manual transmission in NEUTRAL (N). If you have a four-wheel-drive vehicle, be sure the transfer case is not in NEUTRAL (N).

3. Turn off the ignition on both vehicles. Unplug

unnecessary accessories plugged into the cigarette lighter or accessory power outlets, if you have this option. Turn off all lamps that aren’t needed as well as radios. This will avoid sparks and help save both batteries. In addition, it could save your radio!

NOTICE:

I ~~~

If you leave your radio on, it could be badly damaged. The repairs wouldn’t be covered by your warranty.

4. Open the hoods and locate the batteries. Find the positive (+) and negative (-) terminals 011

each battery. A CAUTION:

If your vehicle has air conditioning, the auxiliary electric fan under the hood can start up even when the engine is not running and can injure you. Keep hands, clothing and tools away from any underhood electric fan.

5-3

A CAUTION:

Using a match near a battery can cause battery gas to explode. People have been hurt doing this, and some have been blinded. Use a flashlight if you need more light. Be sure the batteries have enough water. You don’t need to add water to the Delco Freedom@ battery (or batteries) installed in every new GM vehicle. But if a battery has filler caps, be sure the right amount of fluid is there. If it is low, add water to take care of that first. If you don’t, explosive gas could be present. Battery fluid contains acid that can burn you. Don’t get it on you. If you accidentally get it in your eyes or on your skin, flush the place with water and get medical help immediately.

5. Check that the jumper cables don’t have loose or

missing insulation. If they do, you could get a shock. The vehicles could be damaged too. Before you connect the cables, here are some basic things you should know. Positive (+) will go to positive (+) and negative (-) will go to negative (-) or a metal engine part. Don’t connect positive (+) to negative (-) or you’ll get a short that would damage the battery and maybe other parts too.

Fans or other moving engine parts can injure you badly. Keep your hands away .from moving parts once the engines are running.

6. Connect the red positive (+) cable to the positive (+) terminal of the vehicle with the dead battery. Use a remote positive (+) terminal if the vehicle has one.

7 . Don’t let the other end touch metal. Connect it to the positive (+) terminal of the good battery. Use a remote positive (+) terminal if the vehicle has one.

5-5

8. Now connect the

black negative (-) cable to the good battery’s negative (-) cable.

Don’t let the other end touch anything until the next step. The other end of the negative (-) cable doesn’t go to the dead battery. It goes to a heavy unpainted metal part of the vehicle with the dead battery.

9.

10.

11.

Attach the cable at least 18 inches (45 cm) away from the dead battery, but not near engine parts that move. The electrical connection is just as good there, but the chance of sparks getting back to the battery is much less. Now start the vehicle with the good battery and run the engine for awhile. Try to start the vehicle with the dead battery. If it won’t start after a few tries, it probably needs service.

12. Remove the cables in reverse order to prevent

electrical shorting. Take care that they don’t touch each other or any other metal.

A. Heavy Metal Engine Part B. Good Battery C. Dead Battery

Towing Your Vehicle Try to have your GM dealer or a professional towing service tow your vehicle. See “Roadside Assistance” in the Index. If your vehicle has been changed since it was factory-new, by adding such things as fog lamps, aero skirting, or special tires and wheels, these’ instructions may not be correct. Before you do anything, turn on the hazard warning flashers. When you call, tell the towing service:

That your vehicle .has rear-wheel drive, or that it has the four-wheel-drive option. The make, model and year of your vehicle. Whether you can move the shift lever for the transmission and transfer case, if you have one. If there was an accident, what was damaged.

When the towing service arrives, let the tow operator know that this manual contains detailed towing instructions and illustrations. The operator may want to see them.

5-7

/A CAUTION:

I A CAUTION:

To help avoid injury to you or others:

Never let passengers ride in a vehicle that is being towed. Never tow faster than safe or posted speeds. Never tow with damaged parts not fully secured. Never get under your vehicle after it has been lifted by the tow truck. Always use separate safety chains on each side when towing a vehicle. For pickups (except cab chassis models), use T-hooks on front of vehicle, J-hooks on rear. For cab chassis models, use J-hooks on front and rear of vehicle.

5-8

A vehicle can fall from a car carrier if it isn’t adequately secured. This can cause a collision, serious personal injury and vehicle damage. The vehicle should be tightly secured with chains or steel cables before it is transported. Don’t use substitutes (ropes, leather straps, canvas webbing, etc.) that can be cut by sharp edges underneath the towed vehicle.

When your vehicle is being towed, have the ignition key in the OFF position. The steering wheel should be clamped in a straight-ahead position, with a clamping device designed for towing service. Do not use the vehicle’s steering column lock for this. The transmission and transfer case, if you have one, should be in NEUTRAL (N) and the parking brake released. Don’t have your vehicle towed on the drive wheels unless you must. If the vehicle must be towed on the drive wheels, be sure to follow the speed and distance restrictions later in this section or your transmission will be damaged. If these limitations must be exceeded, then the drive wheels have to be supported on a dolly.

Front Towing Tow Limits -- 35 mph (56 k d h ) , 50 miles (SO km) If these limits must be exceeded, then the rear wheels have to be supported on n dolly.

Rear Towing

NOTICE:

Towing pickup models from the rear while loaded with heavy cargo may cause the frame side rails to flex sufficiently to allow the pickup box to contact the cab and could cause damage to the cab and/or box.

5-9

Engine Overheating (Gasoline Engine) You will find a coolant temperature gage on your vehicle’s instrument panel. If your vehicle has a diesel engine, see “Engine Overheating” in the Diesel Engine Supplement. If Steam Is Coming From Your Engine

5-10

A CAUTION:

Steam from an overheated engine can burn you badly, even if you just open the hood. Stay away from the engine if you see or hear steam coming from it. Just turn it off and get everyone away from the vehicle until it cools down. Wait until there is no sign of steam or coolant before opening the hood. If you keep driving when your engine is overheated, the liquids in it can catch fire. You or others could be badly burned. Stop your engine if it overheats, and get out of the vehicle until the engine is cool.

NOTICE:

If your engine catches fire because you keep driving with no coolant, your vehicle can be badly damaged. The costly repairs would not be covered by your warranty.

If No Steam Is Coming From Your Engine If you get the overheat warning but see or hear no steam, the problem may not be too serious. Sometimes the engine can get a little too hot when you:

Climb a long hill on a hot day. 0 Stop after high-speed driving. Idle for long periods in traffic. Tow a trailer. See “Driving on Grades” in the Index. If you get the overheat warning with no sign of steam, try this for a minute or so: I . 2. Turn on your heater to full hot at the highest fan

If you have an air conditioner, turn it off.

speed and open the window as necessary.

3. If you’re in a traffic jam, shift to NEUTRAL (N); otherwise, shift to the highest gear while driving -- AUTOMATIC OVERDRIVE (0) o r THIRD (3) for automatic transmissions.

If you no longer have the overheat warning, you can drive. Just to be safe, drive slower for about 10 minutes. If the warning doesn’t come back on, you can drive normally. If the warning continues, pull over, stop, and park your vehicle right away. If there’s still no sign of steam, push the accelerator until the engine speed is about twice as fast as normal idle speed. Bring the engine speed back to normal idle speed after two or three minutes. Now see if the warning stops. But then, if you still have the warning, turn of the engine nrzd get everyone nut of the vehicle until it cools down. You may decide not to lift the hood but to get service help right away.

5-11

Cooling System -- Gasoline Engines

When you decide it's safe t o lift the hood, here's what you'll see:

A CAUTION:

If your vehicle has air conditioning, the auxiliary electric fan under the hood can start up even when the engine is not running and can injure you. Keep hands, clothing and tools away from any underhood electric fan.

If the coolant inside the coolant recovery tank is boiling, don't do anything else until it cools down.

A. Coolant Recovery Tdnk B. Radiator Pressure Cap C. Engine Fan(s)

A CAUTION:

Heater and radiator hoses, and other engine parts, can be very hot. Don't touch them. If you do, you can be burned. Don't run the engine if there is a leak. If you run the engine, it could lose all coolant. That could cause an engine fire, and you could be burned. Get any leak fixed before you drive the vehicle.

The coolant level should be at or above the COLD mark. If it isn"t, you may have a leak in the radiator hoses, heater hoses, radiator, water pump or somewhere else in the cooling system.

5-13

NOTICE:

I A CAUTION:

Engine damage from running your engine without coolant isn’t covered by your warranty.

If there seems to be no leak, start the engine again. See if the fan speed increases when idle speed is doubled by pushing the accelerator pedal down. If it doesn’t, your vehicle needs service. Turn off the engine. How to Add Coolant to the Coolant Recovery Tank If you haven’t found a problem yet, but the coolant level isn’t at or above the COLD mark, add a SO/SO mixture of ciecu? w t e r (preferably distilled) and DEX-COOL” (orange-colored, silicate-free) antifreeze at the coolant recovery tank. (See (‘Engine Coolant” in the Index for more information.)

Adding only plain water to your cooling system can be dangerous. Plain water, or some other liquid like alcohol, can boil before the proper coolant mix will. Your vehicle’s coolant warning system is set for the proper coolant mix. With plain water or the wrong mix, your engine could get too hot but you wouldn’t get the overheat warning. Your engine could catch fire and you or others could be burned. Use a 50/50 mix of clean water and DEX-COOL TM antifreeze.

I NOTICE:

In cold weather, water can freeze and crack the engine, radiator, heater core and other parts. Use the recommended coolant and the proper coolant mix.

5- 14

You can be burned if’ you spill coolant on hot engine parts. Coolant contains ethylene glycol and it will burn if the engine parts are hot enough. Don’t spill coolant on a hat engine.

When the coolant in the coolant recovery tank is at or above the COLD mark, start your vehicle. If the overheat warning continues. there’s one more thing you can try. You can add the proper coolant mix directly to the radiator, but be sure the cooling system is cool before you do it.

A CAUTION:

Steam and scalding liquids from a hot cooling system can blow out and burn you badly. They pressure cap -- even a little -- they can come out are under pressure, and if you turn the radiator at high speed. Never turn the cap when the cooling system, including the radiator pressure cap, is hot. Wait for the cooling system and radiator pressure cap to cool if' you ever have to turn the pressure cap.

5-16

How to Add Coolant to the Radiator

I . You can remove the radiator pressure cap when

the cooling system, including the radiator pressure cap and upper radiator hose, is no longer hot. Turn the pressure cap slowly counterclockwise until it first stops. (Don't press down while turning the pressure cap. j If you hear a hiss, wait for that t o stop. A hiss means there is still some pressure left.

5-17

3. Fill the radiator with the

proper mix, up to the base of the filler neck.

4. Then fill the coolant recovery tank to the

COLD mark.

5. Put the cap back on the coolant recovery tank, but

leave the radiator pressure cap off.

5-18

6. Start the engine and let it run until you can feel the upper radiator hose getting hot. Watch out for the engine fan(s).

7. By this time the coolant level inside the radiator

filler neck may be lower. If the level is lower, add more of the proper mix through the filler neck until the level reaches the base of the filler neck.

8. Then replace the pressure cap. At any time during this procedure if coolant begins to flow out of the filler neck. reinstall the pressure cap. Be sure the arrows on the pressure cap line up like this.

5-19

Engine Fan Noise Your vehicle has a clutched engine cooling fan. When the clutch is engaged, the fan spins fdster to provide more air to cool the engine. In most every day driving conditions, the fan is spinning slower and the clutch is not fully engaged. This improves fuel economy and reduces fan noise. Under heavy vehicle loading, trailer towing andor high outside temperatures, the fm speed increases as the clutch more fully engages. So you may hear an increase in fan noise. This is normal and should not be mistaken as the transmission slipping or making extra shifts. It is merely the cooling system functioning properly. The fan will slow down when additional cooling is not required and the clutch partially disengages. You may also hear this fm noise when you start the engine. It will go away as the fan clutch partially disengages.

If a Tire Goes Flat It’s unusual for a tire to “blow out” while you’re driving, especially if you maintain your tires properly. If air goes out of a tire, it’s much more likely to leak out slowly. But if you should ever have a “blowout,” here are a few tips about what to expect and what to do: If a front tire fails, the flat tire will create a. drag that pulls the vehicle toward that side. Fake your foot off the accelerator pedal and grip the steering wheel firmly. Steer to maintain lane position, and then gently brake to a stop well out of the traffic lane. A rear blowout, particularly on a curve, acts much like a skid and ITMY require the same correction you’d use in a skid. In any rear blowout, remove your foot from the accelerator pedal. Get the vehicle under control by steering the way you want the vehicle to go. It may be very bumpy and noisy, but you can still steer. Gently brake to a stop -- well off the road if possible. If a tire goes tlat, the next part shows how to use your jacking equipment to change a flat tire safely.

5-20

Changing a Flat Tire If a tire goes flat, avoid further tire and wheel damage by driving slowly to a level place. Turn on your hazard warning flashers.

Changing a tire can cause an injury. The vehicle can slip off the jack and roll over you or other people. You and they could be badly injured. Find a level place to change your tire. To help prevent the vehicle from moving:

To be even more certain the vehicle won't move, you can put blocks at the front and rear of the tire farthest away from the one being changed. That would be the tire on the other side of the vehicle, at the opposite end.

1. Set the parking brake firmly. 2. Put an automatic transmission shift lever in PARK (P) or shift a manual transmission to FIRST (1) or REVERSE: (K).

3. If you have a four-wheel-drive vehicle,

be sure the transfer case is in a drive gear -- not in NEUTRAL (N).

4. Turn off the engine.

CAUTION: (Continued)

The following steps will tell you how to use the jack and change a tire.

5-21

Removing the Spare Tire and Tools

2 and 4-DOOr Models

5-22

Extended Cab Models

The equipment you’ll need is behind the passenger’s seat. Turn the wing nut counterclockwise and remove the jack cover, if there is one. Remove the jacking equipment. If you have a chassis cab, refer to the information from the body supplierhstaller for the location of your spare tire. If you have an underbody-mounted spare, never remove or restow a tire from an underbody carrier while the vehicle is supported only by a jack. You’ll use the jack handle and the ratchet to remove the underbody-mounted spare tire.

Follow these instructions to lower the spare tire: 1 .

One side of the ratchet has an IJP marking. The other side has a DOWN marking. Assenlble the ratchet t o the hook near the end of the jack handle (as illustrated) with the DOWN marking facing you. Insert the other end through the hole in the rear bumper and into the hoist shaft. Turn the ratchet to lower the spare tire to the ground. Continue to turn the ratchet until the spare tire can be plrlled out from under the vehicle. When the tire has been lowered. tilt the retainer at the end of the cable so it can be pulled up through the wheel opening. Put the spare tire near the flat tire.

2.

3.

4.

A. Hoist Assembly B. Ratchet C . Jack Handle D. Hoist Shaft E. Valve Stem,

Pointed Down

E Spare Tire Ci. Retainer H. Hoist Cable

Attach the jack handle (and jack handle extension, if needed) to the jack.

With the IJP marking on the ratchet facing you. rotate the ratchet clockwise. That will lift the jack head

The tools you'll be using include the jack (A), the jack handle extension (B), the jack handle (C), the wheel wrench (D) and the ratchet (E). If the flat tire is on the rear of the vehicle, you'll need the jack handle extension also.

5 -24

If your vehicle has wheel nut caps, use the wheel wrench and ratchet t o remove them. Turn the wheel wrench counterclockwise, with DOWN fdcing you. to remove the wheel nut caps.

Removing the Spare

w Flat Tire and Inst-'

1. Use the ratchet and

wheel wrench to loosen all the wheel nuts. Turn the wheel wrench counterclockwise, with DOWN fdcing you. to loosen the wheel nuts. Don't remove the wheel nuts yet.

Then take off the hub cap. If the wheel also has a trim ring, LISI: to pry along the edge and remove it. If the wheel has a smooth center piece or a center piece with recessed nuts, place the wheel wrench in the slot on the wheel and gently pry out.

the wheel wrench

2. Position the jack under the vehicle.

Getting under a vehicle when it isjacked up is dangerous. If the vehicle slips off the jack, you could be badly injured or killed. Never get under a vehicle when it is supported only by a jack.

NOTICE:

Raising your vehicle with the jack improperly positioned will damage the vehicle or may allow the vehicle to fall off the jack. Be sure to fit the jack lift head into the proper location before raising your vehicle.

Front Position

Rear Position

5-26

Front Position

Rear Position

3. With UP o n the ratchet facing you, raise the vehicle by rotating the ratchet and wheel wrench clockwise. Raise the vehicle far enough off the ground so there is enough room for the spare tire t o fit.

4. Remove all the wheel nuts and take off the flat tire.

5. Remove any rust or dirt

from the wheel bolts, mounting surfaces and spare wheel.

Rust or dirt on the wheel, or on the parts to which it is fastened, can make the wheel nuts become loose after a time. The wheel could come off and cause an accident. When you change a wheel, remove any rust or dirt from the places where the wheel attaches to the vehicle. In an emergency, you can use a cloth or a paper towel to do this; but be sure to use a scraper or wire brush later, if you need to, to get all the rust or dirt off.

I A CAUTIO^:

Never use oil or grease on studs or nuts. If you do, the nuts might come loose. Your wheel could fall off, causing a serious accident.

5-27

6. Replace the wheel nuts with the rounded end of the nuts toward the wheel. Tighten each wheel nut by hand using the wheel. wrench until the wheel is held against the hub.

8. Tighten the nuts

firmly in a criss-cross sequence as shown by rotating the wheel wrench clockwise.

Incorrect wheel nuts or improperly tightened wheel nuts can cause the wheel to become loose and even come off. This could lead to an accident. Be sure to use the correct wheel nuts. If you have to replace them, be sure to get new GM original equipment wheel nuts. Stop somewhere as soon as you can and have the nuts tightened with a torque wrench to the proper torque. See “Capacities and Specifications” in the Index.

~~ Front Position

Rear Position

7. Lower the vehicle by rotating the ratchet and wheel

wrench counterclockwise. Lower the jack completely.

5-28

NOTICE:

Improperly tightened wheel nuts can lead to brake pulsation and rotor damage. To avoid expensive brake repairs, evenly tighten the wheel nuts in the proper sequence and to the proper torque specification.

9. Put the wheel trim back on. For vehicles with plastic wheel nut caps, tighten the caps until they are finger tight, then tighten them an additional one-half turn with the ratchet and wheel wrench.

Storing a Flat or Spare Tire aqd Tools

Storing a jack, a tire or other equipment in the passenger compartment of the vehicle could cause injury. In a sudden stop or collision, loose equipment could strike someone. Store all these in the proper place.

Store the flat tire where the spare tire was stored. For an underbody spare tire carrier, stow the tire under the rear of the vehicle in the spare tire carrier. To stow the tire: 1.

Put the tire on the ground at the rear of the vehicle with the valve stem pointed down and to the rear. Tilt the retainer downward and through the wheel opening. Make sure that the retainer is fully seated across the underside of the wheel. Attach the ratchet, with the UP mark facing you, near the hook at the end of the jack handle. Insert the other end, on an angle, through the hole in the rear bumper and into the hoist shaft. Raise the tire fully against the underslue 01 vehicle. Continue turning the ratchet until mere are two “clicks” or “ratchets.” The spare tire hoist cannot be over-tightened. Grasp and push against the tire to be sure it is stored securely and does not move.

le

2.

3.

4.

5 .

f 29

~~

Lower

Raise

A. Hoist Assembly B. Ratchet C. Jack Handle D. Hoist Shaft

E. Valve Stern,

Pointed Down

E Flat or Spare Tire G. Retainer H. Hoist Cable

Return the jack, ratchet, wheel wrench and jack extensions to their location behind the passenger’s seat. Secure the items and replace the jack cover, if there is one.

2 and 4-Door Models

A. Nut B. Jack C. Jack Handle

Extension

D. Wheel Wrench

E. Jack and Tool Storage Box

E Ratchet G. Jack Handle H. Tool Retainer

5-30

F

Extended Cab Models

Chassis Cab Models

A. Nut B. Jack and Tool

Cover

C. Jack Handle

Extension

D. Tool Retainer

E. Jack and Tool Storage Box

E Ratchet G. Wheel Wrench H. Jack I. Jack Handle

A. Nut €3. Retainer C. Jack Handle

Extension

D. Jack Handle

Extension

E. Wheel Wrench

E Jack and Tool Storage Box

G. Ratchet H. Jack Handle I. Tool Retainer J. Jack

5-31

If You’re Stuck: In Sand, Mud, Ice or Snow What you don’t want to do when your vehicle is stuck is to spin your wheels too fast. The method known as “rocking” can help you get out when you’re stuck, but you must use caution.

-. ..

I NOTICE:

Spinning your wheels can destroy parts of your vehicle as well as the tires. If you spin the wheels too fast while shifting your transmission back and forth, you can destroy your transmission.

- - - -

;. ;

For information about using tire chains on your vehicle, see “Tire Chains” i n the Index.

If you let your tires spin at high speed, they can explode, and you or others could be injured. And, the transmission or other parts of the vehicle can overheat. That could cause an engine compartment fire or other damage. When you’re stuck, spin the wheels as little as possible. Don’t spin the wheels above 35 mph (55 km/h) as shown on the speedometer.

5-32

Using the Recovery Hooks

Rocking your vehicle to get it out: First. turn your steering wheel left and right. That will clear the area around your front wheels. Then shift back and forth between REVERSE (R) and a forward gear (or with a manual transmission, between FIRST (1) or SECOND (2) and REVERSE(R)), spinning the wheels as little as possible. Release the accelerator pedal while you shift. and press lightly on the accelerator pedal when the transmission is in gear. If that doesn't get you out after a few tries. you nlay need to be towed out. Or, you can use your recovery hooks if your vehicle has them. If you do need.to be towed out, see "Towing Your Vehicle" i n the Index.

I The recovery hooks, when used, are under a lot of force. Always pull the vehicle straight out. Never pull on the hooks at a sideways angle. The hooks could break off and you or others could be injured from the chain or cable snapping back.

I I NOTICE: Never use the recovery hooks to tow the vehicle. Your vehicle could be damaged and it would not be covered by warranty.

Section 6 Service and Appearance Care

Here you will find information about the care of your vehicle. This section begins with service and fuel information, and then it shows how to check important fluid and lubricant levels. There is also technical information about your vehicle, and a part devoted to its appearance care. Service Your GM dealer knows your vehicle best and wants you to be happy with it. We hope you’ll go to your dealer for all your service needs. You‘ll get genuine GM parts and GM-trained and supported service people.

We hope you’ll want to keep your GM vehicle a l l GM. Genuine GM parts have one of these marks:

Delco

Doing Your Own Service Work If you want to do some of your own service work. you’ll want to get the proper service manual. It tells you much more about how to service your vehicle than this rnanual can. To order the proper service manual, see “Service and Owner Publications” in the Index.

6 ’

Your vehicle has an air bag system. Before attempting to do your own service work, see “Servicing Your Air Bag-Equipped Vehicle” in the Index. 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” in the Index.

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. 0 Be sure you have sufficient knowledge,

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

0 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.

6-2

Fuel (Gasoline Engine) If your vehicle has a diesel engine, see “Diesel Fuel Requirements and Fuel System” in the Diesel Engine Supplement. For vehicles with gasoline engines, please read-this. Use regular unleaded gasoline rated at 87 octane or higher. At a minimum, it should meet specifications ASTM D4814 in the United States and CGSB 3.5-M93 in Canada. Improved gasoline specifications have been developed by the American Automobile Manufacturers Association (AAMA) for better vehicle performance and engine protection. Gasolines meeting the AAMA specification could provide improved driveability and emission control system protection compared to other gasolines. Be sure the posted octane is at least 87. If the octane is less than 87, you may get a heavy knocking noise when you drive. If it’s bad enough, it can damage your engine. If you’re using fuel rated at 87 octane or higher and you still hear heavy knocking, your engine needs service. But don’t worry if you hear a little pinging noise when you’re accelerating or driving up a hill. That’s normal, and you don’t have to buy a higher octane fuel to get rid of pinging. It’s the heavy, constant knock that means you have a problem.

If your vehicle is certified to meet California Emission Standards (indicated on the underhood tune-up label), it is designed to operate on fuels that meet California specifications. If such fuels are not available in states adopting California emissions standards, your vehicle will operate satisfactorily o n fuels meeting federal specifications, but emission control system performance may be affected. The malfunction indicator lamp on your instrument panel may turn on and/or your vehicle may fail a smog-check test. If this occurs, return to your authorized GM dealer for diagnosis to determine the cause of failure. In the event it is determined that the cause of the condition is the type of fuels used, repairs may not be covered by your warranty. In Canada. some gasolines contain an octane-enhancing additive called MMT. If you use such fuels, your emission control system performance may deteriorate and the tnalfunction indicator lamp on your instrument panel may turn on. If this happens, return t o your authorized CM dealer for service.

To provide cleaner air, all gasolines are now required to contain additives that will help prevent deposits from forming in your engine and fuel system, allowing your emission control system to function properly. Therefore, you should not have to add anything to the fuel. In addition, gasolines containing oxygenates, such as ethers and ethanol, and reformulated gasolines may be available in your area to help clean the air. General Motors recommends that you use these gasolines if they comply with the specifications described earlier.

NOTICE:

Your vehicle was not designed for fuel that contains methanol. Don’t use it. It can corrode metal parts in your fuel system and also damage plastic and rubber parts. That damage wouldn’t be covered under your warranty.

6-3

Filling Your Tank

The fuel cap is behind a hinged door on the left side of your vehicle.

On a chassis-cab model, refuel the front tank first, or in instances when only a partial fuel fill is desired.

Fuels in Fo ign Countries -- Gasoline Engines 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 wouldn’t be covered by your warranty. To check on fuel availability, ask an auto club, or contact a major oil company that does business in the country where you’ll be driving. You can also write us at the following address for advice. Just tell us where you’re going and give your Vehicle Identification Number (VIN).

General Motors Overseas Distribution Corporation, North American Export Sales (NAES) 1908 Colonel Sam Drive Oshawa, Ontario L 1 H 8P7

6-4

‘ J

/i\ CAUTIP

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

Gasoline vapor is highly flammable. It burns violently, and that can cause very bad injuries. Don’t smoke if you’re near gasoline or refueling your vehicle. Keep sparks, flames and smoking materials away from gasoline.

While refueling, hang the cap inside the fuel door.

To take off the. cap, turn it slowly to the left (counterclockwise).

Be careful not to spill gasoline. Clean gasoline from painted surfxes as soon as possible. See “Cleaning the Outside of Your Vehicle” in the Index. When you put the cap back on, turn it to the right until you hear at least three clicks. Make sure you fully install the cap. 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” in the Index.

I NOTICE:

If you need a new 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 or have proper venting, and your fuel tank and emissions system might be damaged.

Checking Things Under the Hood

I !\ CAUTION:

If your vehicle has air conditioning, the auxiliary engine fan under the hood can start up and hjure you even when the engine is not running. Keep hands, clothing and tools away from any underhood electric fan.

Things that burn can get on hot engine parts and start a fire. These include liquids like gasoline or diesel 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.

6-6

Hood Release

To open the hood, first pull the handle inside the vehicle.

Then go to the front of the vehicle and pull up on the secondary hood release, located just to the passenger side of the center of the grill. Lift the l~ood. Before closing the hood, be sure a l l filler caps are on properly. Pull down the hood and close it firmly.

6-7

“VORTEC” 4300,5000,5700 Engine When you lift up the hood you’ll see:

“VORTEC” 5700 engine shown, locations for other engines similar.

A. Battery B. Air Cleaner C. Radiator Cap D. Coolant Recovery T m k E. Air Filter Restriction Indicator E Engine Oil Dipstick G. Automatic Transmission Dipstick

H. Fan I. Power Steering Fluid Reservoir J. Engine Oil Fill K. Brake Fluid Reservoir L. Windshield Washer Fluid Reservoir M. FuseIRelay Center N. Storage Compartment

“VORTEC” 7400 Engine

A. Battery B. Coolant Recovery Tank C. Air Cleaner D. Radiator Cap E. Air Filter Restriction Indicator

K. Brake Fluid Reservoir E Engine Oil Dipstick G. Automatic Transmission Dipstick L. Storage Compartment H. Engine Oil Fill I. Fan J. Power Steering Fluid Reservoir

M. Windshield Washer

Ne Fuse/RelaY Center

Fluid Reservoir

Noise Control System The following information relates to compliance with Federal noise emission standards for vehicles with a Gross Vehicle Weight Rating (GVWR) of more than 10,000 Ibs. (4 536 kg). The Maintenance Schedule booklet provides information on maintaining the noise control system to minimize degradation of the noise emission control system during the life of your vehicle. The noise control system warranty is given in your Warranty booklet. These standards apply only to vehicles sold in the United States. Tampering With Noise Control System Prohibited Federal law prohibits the following acts or the causing thereof: 1. The removal or rendering inoperative by any person,

other than for purposes of maintenance, repair or replacement, of any device or element of design incorporated into any new vehicle for the purpose of noise control. prior to its sale or delivery to the ultimate purchaser or while it is in use; or

2. The use of the vehicle after such device or element of design has been removed or rendered inoperative by any person.

Among those acts presumed to constitute tampering are the acts listed below. Insulation:

Removal of noise shields or underhood insulation.

Engine:

Removal or rendering engine speed governor (if so equipped) inoperative so as to allow engine speed to exceed manufkcturer specifications.

Fan and Drive: 0 Removal of fan clutch (if so equipped) or rendering

clutch inoperative. Removal of fan shroud (if so equipped).

Air Intake:

Removal of air cleaner silencer

@ Reversing air cleaner cover. Exhaust:

Removal of muffler and/or resonator. Removal of exhaust pipes and exhaust pipe clamps. 6-11

Engine Oil (Gasoline Engine) If your vehicle has a diesel engine, see “Engine Oil (Diesel Engine)” in the Diesel Engine Supplement. It’s a good idea to check your engine oil every time you get fuel. In order to get an accurate reading, the oil must be warm and the vehicle must be on level ground.

Turn off the engine and give the oil a few minutes to drain back into the oil pan. If you don’t, the oil dipstick might not.show the actual level. Checking Engine Oil Pull out the dipstick and clean it with a paper towel or cloth, then push it back in all the way. Remove it again, keeping the tip down, and check the level.

The engine oil dipstick has a yellow ring handle and is located on the passenger side of the engine.

6-12

When to Add Oil If the oil is at or below the ADD mark, then you'll need to add some oil. But you must use the right kind. This part explains what kind of oil to use. For crankcase capacity, see "Capacities and Specifications" in the Index

NOTICE:

Don't add too much oil. If your engine has so much oil that the oil level gets above the upper mark that shows the proper operating range, your engine could be damaged.

The engine oil fill cap for the 4.3L, S.OL and the S.7L engine is located on the driver's side engine valve cover.

The engine oil fill cap for the 7.4L engine is located at the front of the engine. Just fill it enough to put the level somewhere in the proper operating range. Push the dipstick all the way hack i n when you're through.

6- 13

What Kind of Oil to Use Oils recommended for your vehicle can be identified by looking for the “Starburst” symbol. This symbol indicates that the oil has been certified by the American Petroleum Institute (API). Do not use any oil which does not carry this Starburst symbol.

~~

If you change your own oil, be sure you use oil that has the Starburst symbol on the front of the oil container.

RECOMMENDED SAE VISCOSITY GRADE ENGINE OILS . . - . . -.

Y AND COLD STARTING, SELECT THE LOWEST FOR BEST FUEL E SAE VISCOSITY Gnnvr ulL FOR THE EXPECTED TEMPERATURE RANGE.

~~~

LOOK

FOR THIS SYMBOL

HOT

WEATHER

+ 3 *

+ 27

If you have your oil changed for you, be sure the oil put into your engine is American Petroleum Institute certified for gasoline engines. You should also use the proper viscosity oil for your vehicle, as shown in the following chart:

’

SAE SW-30 PREFERRED

COLD

WEATHER

DO NOT USE SAE 2OW-50 OR ANY OTHER GRADE OIL NOT RECOMMENDED

6-14

As shown in the chart, SAE 5W-30 is best for your vehicle. However, you can use SAE low-30 if it’s going to be 0°F (-1 8°C) or above. These numbers on an oil container show its viscosity, or thickness. Do not use other viscosity oils, such as SAE 20W-50.

I NOTICE:

Use only engine oil with the American Petroleum Institute Certified For Gasoline Engines “Starburst” symbol. Failure to use the recommended oil can result in engine damage not covered by your warranty.

GM Goodwrench@ oil meets all the requirements for your vehicle. Engine Oil Additives Don’t add anything to your oil. Your GM dealer is ready to advise if you think something should be added.

When to Change Engine Oil See if any one of these is true for you:

Most trips are less than 5 to 10 miles (8 to I6 km). This is particularly important when outside temperatures are below freezing. Most trips include extensive idling (such as frequent driving in stop-and-go traffic). You operate your vehicle in dusty areas or off-road frequently. You frequently tow a trailer. The vehicle is used for delivery service, police, taxi or other commercial application.

Driving under these conditions causes engine oil to break down sooner. If any one of these is true for your vehicle, then you need to change your oil and filter every 3,000 miles (5 000 km) or 3 months -- whichever occurs first. If none of them is true, change the oil and filter every 7,500 miles ( 12 500 km) or I2 months -- whichever occurs first. Driving a vehicle with a fully warmed engine under highway conditions causes engine oil to break down slower.

6-15

What to Do with Used Oil Did you know that used engine oil contains certain elements that may be unhealthy for your skin and could even cause cancer? Don’t let used oil stay on your skin for very long. Clean your skin and nails with soap and water, or a good hand cleaner. Wash or properly throw away clothing or rags containing used engine oil. (See the manufacturer’s warnings about the use and disposal of oil products.) Used oil can be a real threat to the environment. If you change your own oil, be sure to drain all free-flowing oil from the filter before disposal. Don’t ever dispose of oil by putting it in the trash, pouring it on the ground, into sewers, or into streams or bodies of water. Instead, recycle it by taking it to a place that collects used oil. If you have a problem properly disposing of your used oil, ask your dealer, a service station or a local recycling center for help.

Air Cleaner

Your air cleaner is located between the battery and coolant recovery tank.

The air cleaner assembly has an indicator that lets you know when the air filter is dirty and needs to be serviced. The indicator is located in the air intake tube between the air cleaner and the engine.

See “Owner Checks and Services” in the Index on when to check the indicator. If the area inside the clear section of the indicator is green, no air filter service is required. When the area inside the indicator is orange and CHANGE AIR FILTER appears, the filter should be replaced.

To remove the air filter, unhook the retaining clips and remove the cover. Lift the filter and the connected duct out of the air cleaner housing. Hold the duct and remove the filter by both pulling and twisting the filter away fram the duct. Care should be taken to dislodge as little dirt as possible. Clean the filter sealing surface of the duct and the filter housing.

6-17

Refer to the Maintenance Schedule to determine when to replace the air filter. See “Scheduled Maintenance Services” in the Index.

off can

Operating the engine with the air cleaner cause you or others to be burned. The air cleaner not only cleans the air, it stops flame backfires. If it isn’t there, and the engine backfires, you could be burned. Don’t drive with it off, and be careful working on the engine with the air cleaner off.

if the engine

I NOTICE:

If the air cleaner is off, a backfire can cause a damaging engine fire. And, dirt can easily get into your engine, which will damage it. Always have the air cleaner in place when you’re driving.

Install the new filter by pushing it all the way to the stop on the duct. Install the duct and the filter into the air cleaner housing. Make sure that the duct fits properly into the housing. Install the cover and fasten the two retaining clips. After the air filter is properly serviced, the indicator should be reset. Push the button on top of the indicator to reset it to the green (clean) filter zone.

6-18

Automatic Transmission Fluid When to Check a1 C’ -ge A good time to check your auromarlc transmission fluid level is when the engine oil is changed. Change both the fluid and filter every 50,000 miles (83 000 km) if the vehicle’s GVWR is over 8,600 or if the vehicle is mainly driven under one or more of these conditions:

In heavy city traffic where the outside temperature regularly reaches 90°F (32°C) or higher. In hilly or mountainous terrain.

0 When doing frequent trailer towing.

Uses such as found in taxi, police or delivery service.

If your vehicle’s GVWR is not over 8,600 and you do not use your vehicle under any of these conditions, the fluid and filter do not require changing. See “Scheduled Maintenance Services’’ in the Index. How to Check Because this operation can be a little difficult, you may choose to have this done at your GM dealership Service Department.

If you do it yourself, be sure to follow all the instructions here, or you could get a false reading on the dipstick.

NOTICE:

Too much or too little fluid can damage your transmission. Too much can mean that some of i the fluid could come out and fall on hot engine parts or exhaust system parts, starting a fire. Be sure to get an accurate reading if you check your transmission fluid.

Wait at least 30 minutes before checking the transmission fluid level if you have been driving:

When outside temperatures are above 90°F (32°C).

0 At high speed for quite a while.

In heavy traffic -- especially in hot weather. While pulling a trailer.

To get the right reading, the fluid should be at normal operating temperature, which is 180°F to 200°F (82°C to 93°C).

6-19

Checking Transmission Fluid Hot Get the vehicle warmed up by driving about 15 miles (24 km) when outside temperatures are above 50°F (10°C). If it's colder than 50°F (lO"C), drive the vehicle in DRIVE (D) until the engine temperature gage moves and then remains steady for 10 minutes. Then follow the hot check procedures.

Checking Transmission Fluid Cold A cold check is made after the vehicle has been sitting for eight hours or more with the engine off and is used only as a reference. Let the engine run at idle for five minutes if outside temperatures are 50°F (10°C) or more. If it's colder than 50°F (lO"C), you may have to idle the engine longer. Should the fluid level be low during a cold check, you nwst perform a hot check before adding fluid. This will give you a more accurate reading of the fluid level.

Checking the Fluid Hot or Cold 0 Park your vehicle on a level place. Keep the

engine running. With the parking brake applied, place the shift lever in PARK (P). With your foot on the brake pedal, move the shift lever through each gear range, pausing for about

- ,

6-20

three seconds in each range. Then, position the shift lever in PARK (P). Let the engine run at idle for three minutes or more. Then, without shutting off the engine, follow these steps:

The red transmission dipstick handle is located at the rear of the engine compartment, on the passenger side. I . Flip the handle up and then pull out the dipstick and

wipe it with a clean rag or paper towel.

2. Push it back in all the way, wait three seconds and

then pull it back out again.

3. Check both sides of the dipstick, and read the lower

level. The fluid level must be in the COLD area for a cold check or in the HOT area or cross-hatched area for a hot check.

4. If the fluid level is in the acceptable range, push the

dipstick back in all the way; then flip the handle down to lock the dipstick in place.

How to Add Fluid Refer to the Maintenance Schedule to determine what kind of transmission fluid to use. See “Recommended Fluids and Lubricants’’ in the Index. Add fluid only after checking the transmission fluid HOT. (A COLD check is used only as a reference.) If the fluid level is low, add only enough of the proper fluid to bring the level up to the HOT area for a hot check. It doesn’t take much fluid, generally less than a pint (-0.5 L). Don’t overjill. We recommend you use only fluid labeled DEXRON@-111, because fluid with that label is made especially for your automatic transmission. Damage caused by fluid other than DEXRON-I11 is not covered by your new vehicle warranty. 0 After adding fluid, recheck the fluid level as

described under “How to Check.”

0 When the correct fluid level is obtained, push the dipstick back in all the way; then flip the handle down to lock the dipstick in place.

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Manual Transmission Fluid When to Check A good time to have it checked is when the engine oil is changed. However, the fluid in your manual transmission doesn’t require changing. How to Check Because this operation can be a little difficult, you may choose to have this done at your GM dealership Service Department. If you do it yourself, be sure to follow all the instructions here, or you could get a false reading.

NOTICE:

Too much or too little fluid can damage your transmission. Too much can mean that some of the fluid could come out and fall on hot engine parts or exhaust system parts, starting a fire. Be sure to get an accurate reading if you check your transmission fluid.

II

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Check the fluid level only when your engine is off, the vehicle is parked on a level place and the transmission is cool enough for you to rest your fingers on the transmission case. Then, follow these steps:

1. Remove the filler plug. 2. Check that the lubricant level is up to the bottom of

the filler plug hole.

3. If the fluid level is good, install the plug and be sure

it is fully seated. If the fluid level is low, add more fluid as described in the next steps.

How to Add Fluid Here’s how to add fluid. Refer to the Maintenance Schedule to determine what kind of fluid to use. See “Recommended Fluids and Lubricants” in the Index. 1. Remove the filler plug. 2. Add fluid at the filler plug hole. Add only enough fluid to bring the fluid 1evel.u~ to tbe bottom of the filler plug hole.

3. Install the filler plug. Be sure the plug is fully seated. Hydraulic Clutch The hydraulic clutch system in your vehicle is self-adjusting. A slight amount of play (1/4 inch to 1/2 inch or 6 mm to 12 mm) in the pedal is normal. It isn’t a good idea to “top off’ your clutch fluid. Adding fluid won’t correct a leak. A fluid loss in this system could indicate a problem. Have the system inspected and repaired.

When to Check and, What to Use

Refer to the Maintenance Schedule, Owner Checks and Services, to determine how often you should check the fluid level.in your clutch master cylinder reservoir and for the proper fluid. See “Owner Checks and Services” and “Recommended Fluids and Lubricants’’ in the Index.

How to Check The proper fluid should be added if the level does not reach the bottom of the diaphragm when it’s in place in the reservoir. See the instructions on the reservoir cap.

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d Change Lubricant

Rear Axle When to Chc Refer to the Maintenance Schedule to determine how often to check the lubricant and when to change it. See “Scheduled Maintenance Services” in the Index. How to Check Lubricant

C3 (3500 HD) Trucks Equipped with Dana Rear Axle Additional rear axle scheduled maintenance is required on 3500 HD models equipped with Dana rear axles when they are driven under the following conditions:

Extreme loading (at or near GVWR) or trailer towing, and:

0 Operation above 45 mph (70 km/h) for extended

periods of time

Vehicles used in any of these conditions require the rear axle lubricant be changed every 30,000 miles (SO 000 km). Fluid capacity is 4.12 quarts (3.9 L). What to Use Refer to the Maintenance Schedule to determine what kind of lubricant to use. See “Recommended Fluids and Lubricants” in the Index.

If the level is below the bottom of the filler plug hole, you’ll need to add some lubricant. Add enough lubricant to raise the level to the bottom of the filler plug hole.

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How to Check Lubricant

Four-wheel Drive Most lubricant checks in this section also apply to four-wheel-drive vehicles. However, they have two additional systems that need lubrication. Transfer Case M7hen to Check Lubricant Refer to the Maintenance Schedule to determine how often to check the lubricant. See “Periodic Maintenance Inspections’’ in the Index.

If the level is below the bottom of the filler plug hole, you’ll need to add some lubricant. Add enough lubricant to raise the level to the bottom of the filler plug hole. What to Use Refer to the Maintenance Schedule to determine what kind of lubricant to use. See “Recommended Fluids and Lubricants” in the Index.

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Front Axle When to Check and Change Lubricant Refer to the Maintenance Schedule to determine how often t o check the lubricant and when to change it. See "Scheduled Maintenance Services" in the Index.