For time and/or mileage intervals of scheduled maintenance items, refer to Maintenance Schedule .
The following text and illustrations describe the details of the required scheduled maintenance services.
For information on the proper fluids and lubricants to use, refer to Fluid and Lubricant Recommendations .
For the engine oil and filter changing procedure, refer to Engine Oil and Oil Filter Replacement for a 4.3 L engine.
Refer to Engine Oil and Oil Filter Replacement for a 4.8 L engine, 5.3 L engine and 6.0 L engine.
Refer to Engine Oil and Oil Filter Replacement for a 8.1 L engine.
For information on the correct engine oil quality and viscosity, refer to the following:
Oils of the proper quality for the vehicle can be identified by looking for the STARBURST symbol. The STARBURST symbol indicates that the oil has been certified by the American Petroleum Institute (API), and is preferred for use in gasoline engines.
The recommended oil viscosity is SAE 5W-30.
Notice: Using oils of any viscosity other than those recommended could result in engine damage. When choosing an oil, consider the range of temperatures the vehicle will be operated in before the next oil change. Then, select the recommended oil viscosity.
Engine oil viscosity (thickness) has an effect on the fuel economy and the cold-weather operation (starting and oil flow). Lower viscosity engine oils can provide better fuel economy and cold-weather performance. However, higher temperature weather condition require higher viscosity engine oils for satisfactory lubrication. When the temperature is consistently above -18°C (0°F), SAE 10W-30 can be used. SAE 20W-50 or oils of other viscosity rating or quality designations are NOT recommended for use in any Trucks at any time.
Notice: Do not lubricate the parking brake cables. Lubrication destroys the plastic coating on the cable.
Refer to the illustration for the location of the lubrication points for the chassis. Lubricate the transmission shift linkage. Lubricate the park brake guides, the underbody contact points and the linkage.
Important: Wipe off all dirt from the grease fitting before lubricating the joint. Ball joints should not be lubricated unless the temperature of the ball joints is -12°C (10°F) or higher. During cold weather, allow the ball joint to warm up as necessary before being lubricated. Use a low-pressure grease gun on all joints in order to prevent seal damage.
Apply grease slowly while watching the grease seal. Apply the grease until the grease is seen bleeding from the seal. If the seal expands but you do not see any grease, do not apply any more grease. Allow time for the grease to bleed from the seal.
Lubricate the steering linkage, the upper and the lower ball joint.
Inspect the tires for abnormal wear or damage. Rotate the tires in order to equalize the wear and obtain maximum tire life. Refer to Tire Rotation in Tires and Wheels. If irregular or premature wear exists, refer to Tire Diagnosis - Irregular or Premature Wear or Tire Diagnosis - Waddle Complaint in Tires and Wheels.
Inspect the accessory drive belts for the following:
Replace as needed. (Belts can have many small cracks in individual ribs without affecting the performance.) Refer to Drive Belt Replacement for the 4.3 L Engine.
Refer to Drive Belt Replacement - Accessory or Air Conditioning Compressor Belt Replacement for the 4.8 L, 5.3 L, 6.0 L Engine.
Refer to Drive Belt Replacement - Accessory or Air Conditioning Compressor Belt Replacement for the 8.1 L Engine.
Change both the fluid and the filter according to the maintenance schedule intervals. For maintenance schedule information, refer to Maintenance Schedule .
For the fluid and filter changing procedure, refer to Automatic Transmission Fluid and Filter Replacement 4L60-E in Automatic Transmission or Automatic Transmission Fluid and Filter Replacement 4L80-E in Automatic Transmission.
Refer to Automatic Transmission Fluid and Filter Replacement .
Change transfer case fluid.
For replacement procedure refer to Transfer Case Fluid Replacement for a One Speed Automatic or Transfer Case Fluid Replacement for a Two Speed Automatic.
Change both the fluid and the filter on the five-speed manual transmission according to the maintenance schedule intervals. For maintenance schedule information, refer to Maintenance Schedule .
For the fluid and filter changing procedure, refer to Fluid Replacement for the New Venture 3500 Transmission or Fluid Replacement for the New Venture 4500 Transmission.
Clean the spark plug wires. Inspect the spark plug wires for burns, cracks or other damage. Inspect the wire boot fit at the coils and at the spark plugs. Replace the wires as needed. For the 4.3 L engine, refer to Spark Plug Wire Replacement .
For the 4.8 L, 5.3 L, 6.0 L engine, refer to Spark Plug Wire Replacement .
For the 8.1 L engine, refer to Spark Plug Wire Replacement .
Replace the spark plugs according to the maintenance schedule intervals with the correct type. For maintenance schedule information, refer to Maintenance Schedule .
For information on the correct type of spark plug, refer to Maintenance Items .
For the 4.3 L engine spark plug replacement procedure, refer to Spark Plug Replacement .
For the 4.8 L, 5.3 L, 6.0 L engine spark plug replacement procedure, refer to Spark Plug Replacement .
For the 8.1 L engine spark plug replacement procedure, refer to Spark Plug Replacement .
Replace the fuel filter according to the maintenance schedule intervals with the correct type. For maintenance schedule information, refer to Maintenance Schedule .
Replace the passenger compartment air filter. Refer to Passenger Compartment Air Filter Replacement in Heating, Ventilation, and Air Conditioning.
Change the axle fluid according to the maintenance schedule intervals. Refer to Maintenance Schedule .
For axle capacities refer to Approximate Fluid Capacities .
For the procedure to check the fluid level refer to Lubricant Level Check .
Drain, flush and refill the cooling system with new coolant. Refer to Cooling System Draining and Filling in Engine Cooling.
For time and or mileage intervals of scheduled maintenance items, refer to Maintenance Schedule .
For the engine oil and filter changing procedure, refer to Engine Oil and Oil Filter Replacement in Engine Mechanical.
This doughnut-shaped logo (symbol is used on most oil containers to help you select the correct oil. It means that the oil has been certified by the American Petroleum Institute.
You should look for this on the oil container, and use only those oils that display the logo.
Oils designated as API CH-4 or CG-4 are best. The CH-4 or CG-4 designations may appear either alone, together or in combination with other API designations, such as API CH-4/SJ, CG-4/SH or CH-4/CG-4/SJ.
These letters show American Petroleum Institute (API) levels of quality.
Important: Oils that do not have one of these designations (CH-4 or CG-4) can cause engine damage which is not covered by the warranty.
The recommended oil viscosity is SAE 15W-40.
Important: However, you can use SAE 10W-30 if temperatures stay above -18°C (0°F) before your next oil change. When it is very cold, below -18°C (0°F), you should use SAE 5W-30 to improve cold starting and prevent engine damage.
Inspect the tires for abnormal wear or damage. Rotate the tires in order to equalize the wear and obtain maximum tire life. Refer to Tire Rotation in Tires and Wheels. If irregular or premature wear exists, refer to Tire Diagnosis - Irregular or Premature Wear in Tires and Wheels.
Refer to Drive Belt Replacement for the 6.6 L Engine.
Refer to Automatic Transmission Fluid and Filter Replacement Allison Transmission.
For information on the correct type of fuel filter, refer to Maintenance Items .
Change the axle fluid according to the maintenance schedule intervals. For the maintenance schedule refer to Maintenance Schedule .
For axle capacities, refer to Approximate Fluid Capacities .
For the procedure to check the fluid level, refer to Lubricant Level Check .
Inspect the shields and underhood insulation condition. Replace the shields and underhood insulation if damaged.
