ApplicationCapacities
English Metric
23082T (H25) 44.0 pt 20.8 L
26080T (GJ4) 44.0 pt 20.8 L
Transfer Case (Four-Wheel Drive) 4.0 pt 1.9 L
Transmission Fluid, Automatic
3000 RDS and EVS, and 3500 RDS and EVS 52.0 pt 24.6 L
1000 HS, RDS, MH, PTS and EVS, 2200 HS, RDS, MH,
PTS and EVS, 2500 HS and RDS, and 2300 HS and RDS35.0 pt 13.5 L
Add 2 pints (1 L) when changing spin-on or remote filter.
See the Allison
®Automatic Transmission Operator’s Manual for fluid check and maintenance information.
Transmission Fluid, Manual
FS5205A, FS5205C 11.6 pt 5.5 L
FS6305A, FS6305B, 18.4 pt 8.7 L
FS5406, FSO8406 18.5 pt 8.8 L
RT6609 12.5 pt 5.9 L
RT8709B 25.1 pt 11.8 L
RT8908LL 29.1 pt 13.8 L
ZF S6-650 12.7 pt 6.0 L
All capacities are approximate. When adding, be sure to fill to the approximate level, as recommended in this
manual. Recheck the fluid level after filling.
5-103
Part GM Part Number ACDelco®Part Number
Spark Plugs
6.6L — —
7.2L — —
7.8L — —
8.1L 12578277 41-983
1Optional air filter (GM Part No. 88937548 AC Delco No. A2035C) for C6/C7/C8 Models. Fits inside standard size
filter (GM Part No. 88937525 AC Delco No. A2031C) listed previously.
†Racor part number.
††Caterpillar
®part number.
See the Allison Transmission®Operator’s Manual in your vehicle for external filter part numbers and information.
5-106
Part A: Scheduled Maintenance
Services
In this part are scheduled maintenance services which
are to be performed at the mileage intervals specified.
Using the Maintenance Schedule
We at General Motors want to help keep your vehicle in
good working condition. But we do not know exactly
how you will drive it. You may drive very short distances
only a few times a week. Or you may drive long
distances all the time in very hot, dusty weather. You
may use your vehicle in making deliveries or in
many other ways.
Because of all the different ways people use their
vehicles, maintenance needs vary. You may need more
frequent checks and replacements. So please read
the following and note how you drive. If you have any
questions on how to keep your vehicle in good condition,
see your dealer.
This part tells you the maintenance services you should
have done and when to schedule them.
When you go to your dealer for your service needs, you
will know that GM-trained and supported service
people will perform the work using genuine GM parts.The proper fluids and lubricants to use are listed in
Part C. Make sure whoever services your vehicle uses
these. All parts should be replaced and all necessary
repairs done before you or anyone else drives the
vehicle.
This schedule is for vehicles that:
•carry passengers and cargo within recommended
limits. You will find limits on your vehicle’s GVW
Rating label. SeeLoading Your Vehicle on
page 4-34.
•are driven on reasonable road surfaces within legal
driving limits.
•use the recommended fuel. SeeGasoline Octane
on page 5-6for gasoline engine vehicles orWhat
Fuel to Use on page 5-8for diesel engine vehicles.
Scheduled Maintenance
Supplements
If your vehicle has a Caterpillar®diesel engine, your
owner’s manual is supplemented by the Caterpillar®
Diesel Engine Operation & Maintenance Manual. If your
vehicle has an Allison Transmission®, your owner’s
manual is supplemented by an Allison Transmission®
Operator’s Manual. Always refer to these manuals
for related maintenance services.
6-4
❑Except four-wheel drive: Front axle service.(31)
❑Four-wheel drive only: Front axle service.(30)
❑Four-wheel drive only: Transfer case service.(30)
❑Rear axle service — Eaton
®, Rockwell®, Spicer®
axles (or every 12 months, whichever occurs
first).(30)
❑Exhaust brake service, if equipped. Check for
excessive spindle free play and smooth operation.
Lubricate ball joint cap.
❑Inspect air compressor discharge port (or every
6 months or every 1,800 hours, whichever
occurs first).
❑Manual transmission (ZF 6-speed only) fluid
replacement (or every 48 months, whichever
occurs first).
❑Trailer brake hand control valve service (or every
12 months, or every 3,600 hours, whichever
occurs first).(35)
120,000 Miles (192 000 km)
❑C600, C700, and C800 Gasoline Engines
Only: Replace engine drive belts.
❑C400 and C500 Gasoline Engines Only: Engine drive
belts service (or every 12 months, whichever occurs
first).(17)
150,000 Miles (240 000 km)
❑Cooling system service (or every 60 months since
last service, whichever occurs first).(2) (29)
❑Diesel Engine Only: Inspect engine drive belt;
replace as necessary.
200,000 Miles (320 000 km)
❑Remove, disassemble, clean, and inspect the air
brake trailer supply valve (or every 2 years, or
every 7,200 hours, whichever occurs first).
❑Diesel Engine Only: Inspect engine drive belt;
replace as necessary.
250,000 Miles (400 000 km)
❑Four-wheel drive only: Front axle service.(30)
❑Four-wheel drive only: Transfer case service.(30)
❑Manual transmission (except ZF 6-speed) fluid
replacement (or every 60 months, whichever
occurs first).
300,000 Miles (480 000 km)
❑Remove, disassemble, clean, and inspect the air
brake air dryer (or every 3 years, or 10,800 hours,
whichever occurs first). Replace desiccant.
6-21
Footnotes
† = The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to
the completion of the vehicle’s useful life. We, however,
urge that all recommended maintenance services be
performed at the indicated intervals and the
maintenance be recorded.
(1)= If your vehicle has an Allison Transmission
®, your
GM owner manual is supplemented by an Allison
Transmission
®Operator’s Manual. Always refer to these
manuals for related maintenance services.
(2)= An Emission Control Service.
(3)= A Noise Emission Control Device.
(4)= Applies to vehicles sold in the United States and is
recommended for vehicles sold in Canada.(5)= Check fluid level in brake master cylinder, power
steering pump, axle, transmission, and hydraulic
spring parking brake pump (if equipped). A low fluid
level in the brake master cylinder can indicate
worn brake linings and should be checked accordingly.
(6)= Inspect brake lines and hoses for proper
hook-up, binding, leaks, cracks, chafing, etc. Inspect
disc brake pads for wear and rotors for surface
condition. Inspect caliper assemblies. Check brake
pedal for excessive free play or travel (or every
6 months, whichever occurs first) and have serviced if
needed. Check brakes more often if driving habits
and conditions result in frequent braking.
(7)= This vehicle has the Engine Oil Life System. This
system will show you when to change the engine oil
and filter — usually between 3,000 miles (5 000 km) and
12,000 miles (20 000 km) since your last oil change.
Under severe conditions, the indicator may come
on before 3,000 miles (5 000 km). Never drive your
7.8L diesel engine vehicle more than 12,000 miles
(20 000 km), or 12 months, or 600 engine hours, without
an oil and filter change.
6-22
(11)= Chassis Lubrication Service: Lubricate all grease
fittings in front suspension, front axle, and steering
linkage. DO NOT lubricate kingpin bushings with
air pressure equipment; instead, use a hand grease gun
to ensure complete purge and eliminate sealer cap
distortion. Front axle tie rod ends, both upper and lower
kingpin fittings, and both steering linkage relay rod
ends should be greased with the vehicle loaded on the
ground and wheels turned straight ahead, NOT with
the vehicle on a hoist. Apply kingpin bushing lubricant to
both upper and lower kingpin grease fittings until new
lubricant purges from between the upper shim pack and
thrust bearing. Lubricate transmission and shift
linkage, hood latches and hood hinges, parking brake
lever pivot, clevis pins and linkage, disc brake caliper
rails, clutch linkage and release bearing (if equipped),
bearing pads, propshaft universal joints, brake camshaft
bracket, slack adjusters, pedal shaft, clutch cross
shaft, clutch pedal springs, and clutch cable bushing at
transmission. Lubricate suspension, axle, and steering
linkage more often when operating under dusty or
muddy conditions and in excessive off-road use.
Frequently power-washed vehicles will require more
frequent lubrication.(12)= Check steering system:
•Look for damaged, loose, or missing parts. Inspect
the steering linkage relay rod and tie rod ends for
looseness or lack of lubricant. Also look for
parts showing signs of wear or lack of lubrication.
Replace parts as needed. Also check steering gear
mounting bolts, pitman arm nut, gear housing
upper cover and side cover attaching bolts, steering
column mounting bolts and cardan joint clamp
bolts; tighten if necessary. See the service manual.
•Inspect power steering hoses, tubes, and fittings for
leaks. Hoses and lines must not be twisted, kinked,
or tightly bent. Make sure clips, clamps, supporting
tubes, and hoses are in place and properly
secured.
•Check steering gear for leakage around pitman
shaft and housing. If leakage is evident (lubricant
oozing out, not just oily film), leak should be
corrected immediately.
(13)= Check front and rear suspension. Look for
damaged, loose, or missing parts or parts showing signs
of wear or lack of lubrication. Replace parts as
needed.
6-24
Starter Switch Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough room
around the vehicle.
2. Firmly apply both the parking brake and the regular
brakes.
Do not use the accelerator pedal, and be ready to
turn off the engine immediately if it starts.
3. On automatic transmission vehicles, try to start the
engine in each gear. The starter should work only
in PARK (P), if equipped, or NEUTRAL (N). If
the starter works in any other position, your vehicle
needs service. On manual transmission vehicles,
the starter should work only when the clutch pedal is
all the way down.
Automatic Transmission Shift
Indicator Check
Check that the indicator points to the gear chosen.
Steering Check
Be alert for any changes in steering action, abnormal
front tire wear or steering wheel position. An inspection
or service is needed when the steering wheel is
harder to turn or has too much free play, or if there are
strange sounds when turning or parking.
Brake System Check
Be alert to illumination of the low air warning lamp or for
the tone alarm, or changes in braking action, such as
repeated pulling to one side, unusual sounds when
braking or increased brake pedal travel. Make sure air
brake system reservoirs are drained daily with full
system air pressure, and check system for leaks. Any of
these conditions could indicate the need for brake
system inspection and/or service.
Engine Cooling System Service
Inspect the hoses and have them replaced if they are
cracked, swollen, or deteriorated. Inspect all pipes,
fittings, and clamps; replace as needed. Clean
the outside of the radiator and air conditioning
condenser. To help ensure proper operation, a pressure
test of the cooling system and pressure cap is
recommended at least once a year.
6-30
Part C: Recommended Fluids
and Lubricants
Fluids and lubricants identified below by name, part
number, or specification may be obtained from
your dealer.
Usage Fluid/Lubricant
Engine Oil
(Gasoline
Engine)Engine oil which meets GM
Standard GM6094M and displays
the American Petroleum Institute
Certified for Gasoline Engines
starburst symbol. GM Goodwrench
®
oil meets all the requirements for
your vehicle. To determine the
proper viscosity for your vehicle’s
engine, see “Engine Oil” in the
Index.
Engine Oil
(DURAMAX
®
Diesel Engine)Engine oil with the letters CI-4 or
CH-4 is best for your vehicle. The
CI-4 or CH-4 designation may
appear either alone or in
combination with other API
designations, such as API CI-4/SL.
These letters show American
Petroleum Institute levels of quality.
To determine the preferred viscosity
for your vehicle’s diesel engine, see
“Engine Oil” in the Index.
Engine Oil
(Caterpillar
®
Diesel Engine)See the Caterpillar
®Operation &
Maintenance Manual for engine oil
recommendations.
Usage Fluid/Lubricant
Engine Coolant
(Caterpillar
®
Diesel Engine)See the Caterpillar
®Operation &
Maintenance Manual for engine
coolant recommendations.
Engine Coolant
(Gasoline
Engine &
DURAMAX
®
Diesel)50/50 mixture of clean, drinkable
water and use only DEX-COOL
®
Coolant. SeeEngine Coolant
(Gas and DURAMAX®Engines) on
page 5-38orEngine Coolant
(Caterpillar
®Diesel Engines) on
page 5-40.
Hydraulic Brake
SystemDelco
®Supreme 11 Brake Fluid or
equivalent DOT-3 brake fluid.
Windshield
Washer SolventGM Optikleen
®Washer Solvent.
Clutch Bearing
LubricantClutch Bearing Lubricant
(GM Part No. 12378484 or
equivalent NLGI #3 consistency).
Exhaust Brake
Ball Joint Cap
LubricantHigh-Temperature Grease
(GM Part No. U.S. 1051344, in
Canada 903037) or NLGI #3
consistency.
Power Steering
SystemDEXRON
®-VI Automatic
Transmission Fluid.
Manual
Transmission
(Except ZF
6-Speed)Synthetic Manual Transmission Fluid
(GM Part No. U.S. 12345724, in
Canada 10953510).
6-33