Page 283 of 398
Item Number Item Remarks
1 Brake Camshaft** One fitting each (apply sparingly).
2 Steering Column Slip Joint* One fitting.
3 Steering Drag Link Ends One fitting each end.
4 Pivot Points and Hinges Apply chassis lubricant.
5 Pivot Points and Hinges Apply chassis lubricant.
6 Slack Adjuster** One fitting.
7Brake Cam Roller Pins at interface
of pin and shoe**Apply engine oil.
8 Front Steering KnucklesOne fitting each side, lower bushing.
(Hand-operated grease gun only.)
Hand-pack upper bearing.
9 Front Wheel Bearings Hand-pack or lubricate.
10 Steering Tie Rod Ends One fitting each end.
11 Spring Slip Pads* (Multi-Leaf Only) Apply chassis lubricant.
12 Clutch Release Bearing* Cup or fitting.
5-55
Page 285 of 398
Tandem Axle ModelsItem
Number Item Remarks
1 Brake Camshafts One fitting each.
2 Propshaft U-JointOne fitting each
joint. Lubricate with
GM Part
No. 1051344, Wheel
Bearing Lubricant
3 Rear AxlesFill to level of
filler plug.
4Brake Shoe
Roller PinsApply engine oil at
pin to shoe
joint only.
5 Rear Spring PinOne fitting
each side.
5-57
Page 299 of 398

Primary Fuel Filter and
Water Separator
If you have a diesel
engine, you may have this
spin-on filter. It is located
on the driver’s side
frame rail.
It has a clear plastic drain bowl at the bottom. Check
the drain bowl occasionally for any water or particles.
To drain the bowl, do the following:
1. Shut off the engine.
2. Partially open the drain valve at the bottom of
the filter.
SeeEngine Oil (Caterpillar
®Diesel Engine) on
page 5-24orEngine Oil (DURAMAX®Diesel) on
page 5-24orEngine Oil (Gasoline Engine) on page 5-28
for proper disposal procedures.
Secondary Fuel Filter and
Water Separator/Heater
(Caterpillar
®Diesel)
If you have a Caterpillar®
diesel engine, you may
also have this spin-on filter
and fuel separator/heater.
It will be mounted in
the engine compartment
on the driver’s side of
the vehicle.
It has a metal drain bowl at the bottom. Occasionally,
check the bowl for any water or particles.
To check or drain the bowl, do the following:
•Shut off the engine.
•Push up on the spring loaded drain valve until clear
fuel is flowing from the valve.
The particles or water will drain out first. SeeEngine Oil
(Caterpillar
®Diesel Engine) on page 5-24orEngine
Oil (DURAMAX®Diesel) on page 5-24orEngine
Oil (Gasoline Engine) on page 5-28for proper disposal
procedures.
5-71
Page 300 of 398
Automatic Ether Injection System
(Caterpillar
®Diesel)
If you have a Caterpillar®
diesel engine, you may
have this feature. The
ether cylinder is located in
the engine compartment
on the driver’s side of
the vehicle.
To change an empty ether cylinder, follow these steps.
1. Loosen the screw head on the cylinder-to-bracket
clamp.
2. Spread the clamp apart.3. Clean any dirt from the neck of the cylinder and the
top of the valve before you take out the cylinder.
4. Check the inside of the valve for any foreign matter.
Clean the valve as necessary.
5. Cover the valve to protect it from dirt and take out
the cylinder.
6. Install a new gasket whenever you take out the
cylinder. Use only one gasket and spread a light
film of clean oil on it before installation.
7. Put in the new cylinder. Turn it clockwise until it just
starts to contact the gasket.
8. Tighten the cylinder another half turn (180 degrees).
Don’t over-tighten.
9. Retighten the cylinder clamp.
5-72
Page 328 of 398
ApplicationCapacities
English Metric
7.2L 250 - 300 hp Engine 32.8 qt 31.0 L
7.2L 250 - 300 hp Engine with A/C and Increased Cooling 33.3 qt 31.5 L
7.8L 200 - 230 hp Engine 31.6 qt 29.9 L
7.8L 200 - 230 hp Engine with A/C and Increased Cooling 35.3 qt 33.4 L
7.8L 250 - 300 hp Engine 34.9 qt 33.0 L
7.8L 250 - 300 hp Engine with A/C and Increased Cooling 35.4 qt 33.5 L
8.1L 225 - 295 hp Engine 33.3 qt 31.5 L
8.1L with A/C and Increased Cooling 34.9 qt 33.0 L
Engine Oil with Filter
6.6L 14.6 qt 13.8 L
7.2L 30.0 qt 28.4 L
7.8L
123.8 qt 22.5 L
8.1L 10.0 qt 9.4 L
Check fill level on the oil indicator after initial fill to make sure it is actually full. Oil level may vary depending on
vehicle option content.
1Additional oil is required with auxiliary oil filter systems. Make sure to add enough extra oil to fill the auxiliary oil
filter system. For vehicles equipped with the LUBERFINER 750-C, add 14 quarts (13.25 L).
5-100
Page 333 of 398
Part GM Part Number ACDelco®Part Number
Engine Oil Filter
6.6L 88917036 PF2232
7.2L — 1R-1807††
7.8L 94037791 —
8.1L 25324052 PF454
Fuel Filter
6.6L 97385488 TP1298A
7.2L — 1R-0751††
7.8L 94392474 —
8.1L (NG6/NK1) 21998364 —
8.1L (All others) — S3202†
Power Steering Fluid Filter 88892858 —
Secondary Fuel Filter
6.6L — —
7.2L 25014274 TP915D
7.2L (KUK) 88983117 TP1519
7.2L (NWB) 15618921 —
7.8L 25014274 TP915D
7.8L (KUK) 88983117 TP1519
8.1L (K28 and standard Uhaul) 25014476 TP1247
5-105
Page 336 of 398

Maintenance Schedule
Introduction
Important: Keep engine oil at the proper level and
change as recommended.
Have you purchased the GM Protection Plan? The Plan
supplements your new vehicle warranties. See your
Warranty and Owner Assistance booklet or your dealer
for details.
Maintenance Requirements
Maintenance intervals, checks, inspections and
recommended fluids and lubricants as prescribed in this
manual are necessary to keep your vehicle in good
working condition. Any damage caused by failure
to follow scheduled maintenance may not be covered by
warranty.
Your Vehicle and the Environment
Proper vehicle maintenance not only helps to keep your
vehicle in good working condition, but also helps the
environment. Improper vehicle maintenance can
even affect the quality of the air we breathe. Improper
fluid levels or the wrong tire inflation can increase
the level of emissions from your vehicle. To help protect
our environment, and to keep your vehicle in good
condition, be sure to maintain your vehicle properly.
6-2
Page 339 of 398

Scheduled Maintenance
The services shown in this schedule up to 100,000 miles
(166 000 km) should be repeated after 100,000 miles
(166 000 km) at the same intervals for the life of
this vehicle. The services shown after 100,000 miles
(166 000 km) should be repeated at the same miles (km)
after those intervals for the life of this vehicle.
Gasoline engine vehicles and some DURAMAX
®diesel
engine vehicles have a computer that lets you know
when to change your engine oil. This is not based
on mileage, but on engine operation and engine
temperature. When the computer has calculated that the
oil needs changing, the Engine Oil Life System will
indicate that a change is necessary. SeeEngine Oil Life
System (Gasoline Engine) on page 5-31orEngine Oil
Life System (DURAMAX
®Diesel) on page 5-33or
Engine Oil Life System (Caterpillar®Diesel Engine) on
page 5-34.
The “Footnotes” at the end of this Maintenance
Schedule further explain maintenance services.
SeeService Publications Ordering Information on
page 7-11.
100 Miles (160 km)
❑Wheel stud nut service.(36)
1,000 Miles (1 600 km)
❑Wheel stud nut service.(36)
❑Rear axle air shift motor service.(10)
7,500 Miles (12 000 km)
❑Gasoline Engine Only: Check engine oil life system.
If engine oil and filter are changed, reset system.
See “Engine Oil (Gasoline Engine)” in the
Index.(2) (8)
❑Check fluid levels (or every 3 months, whichever
occurs first).(1) (5)
❑Chassis lubrication service (or every 6 months,
whichever occurs first).(11)
❑Wheels and tires service.(14)
❑Hydraulic brake service (or every 6 months,
whichever occurs first).(6) (36)
❑Parking brake service (or every 6 months, whichever
occurs first).(21)
6-5