2003 CHEVROLET SILVERADO Transmission

qReplace engine air cleaner ®lter on vehicles without
a restriction indicator. If equipped with a change
indicator, inspect the indicator. If necessary, replace
the ®lter. If vehicle is driven in dusty/dirty conditions,
inspect the change indicator (if equipped) at every
engine oil change. See
Engine Air Cleaner/Filter on
page 5-21for more information.An Emission
Control Service. (See footnote ².)
qInspect Evaporative Control System. Check all fuel
and vapor lines and hoses for proper hook-up,
routing and condition. Check that the purge valve
works properly, if equipped. Replace as needed.
An
Emission Control Service. (See footnote ².)
67,500 Miles (112 500 km)
qCheck rear/front axle ¯uid level and add ¯uid as
needed. Check constant velocity joints and axle seals
for leaking.
qRotate tires. See
Tire Inspection and Rotation on
page 5-71for proper rotation pattern and additional
information.(See footnote +.)
75,000 Miles (125 000 km)
qInspect engine air cleaner ®lter or change indicator (if
equipped). If necessary, replace the ®lter. If vehicle is
driven in dusty/dirty conditions, inspect ®lter or
change indicator (if equipped) at every engine oil
change. See
Engine Air Cleaner/Filter on page 5-21for more information.An Emission Control Service.
(See footnote ².)
qCheck rear/front axle ¯uid level and add ¯uid as
needed. Check constant velocity joints and axle seals
for leaking.
qAllison Transmission
žOnly: Change automatic
transmission ¯uid and ®lter if the vehicle is mainly
driven under one or more of these conditions:
þ In heavy city traffic where the outside
temperature regularly reaches 90ÉF (32ÉC) or
higher.
þ In hilly or mountainous terrain.
þ When doing frequent trailer towing.
þ Uses such as found in taxi, police or delivery
service.
If you do not use your vehicle under any of these
conditions, change the ¯uid and ®lter at 100,000 miles
(166 000 km).
qRotate tires. SeeTire Inspection and Rotation on
page 5-71for proper rotation pattern and additional
information.(See footnote +.)
6-9

100,000 Miles (166 000 km)
qInspect spark plug wires.An Emission Control
Service.
qReplace spark plugs.An Emission Control Service.
qChange automatic transmission ¯uid and ®lter if
the vehicle's GVWR is over 8600 lbs, if the
vehicle has an Allison transmission or if the vehicle is
mainly driven under one or more of these conditions:
þ In heavy city traffic where the outside
temperature regularly reaches 90ÉF (32ÉC) or
higher.
þ In hilly or mountainous terrain.
þ When doing frequent trailer towing.
þ Uses such as found in taxi, police or delivery
service.
qIf you haven't used your vehicle under severe service
conditions listed previously and, therefore, haven't
changed your automatic transmission ¯uid, change
both the ¯uid and ®lterqAutomatic Transfer Case Only: Change transfer case
¯uid
qExcept 8.1L V8 Engine: Inspect Positive Crankcase
Ventilation (PCV) valve.
An Emission Control
Service.
150,000 Miles (240 000 km)
qDrain, ¯ush and re®ll cooling system (or every
60 months since last service, whichever occurs ®rst).
See
Engine Coolant on page 5-30for what to use.
Inspect hoses. Clean radiator, condenser, pressure
cap and neck. Pressure test the cooling system
and pressure cap.
An Emission Control Service.
qChange ®ve-speed manual transmission ¯uid (with
4300 V6 or 4800 V8 engines only).
qInspect engine accessory drive belt.
An Emission
Control Service.
200,000 Miles (332 000 km)
q6000 V8 Engine Only: Change ®ve-speed manual
transmission ¯uid.
6-11

At Least Twice a Year
Restraint System Check
Make sure the safety belt reminder light and all your
belts, buckles, latch plates, retractors and anchorages
are working properly. Look for any other loose or
damaged safety belt system parts. If you see anything
that might keep a safety belt system from doing its
job, have it repaired. Have any torn or frayed safety belts
replaced.
Also look for any opened or broken air bag coverings,
and have them repaired or replaced. (The air bag
system does not need regular maintenance.)
Wiper Blade Check
Inspect wiper blades for wear or cracking. Replace
blade inserts that appear worn or damaged or that
streak or miss areas of the windshield. Also see
Cleaning the Outside of Your Vehicle on page 5-103.
Spare Tire Check
At least twice a year, after the monthly in¯ation check of
the spare tire determines that the spare is in¯ated to
the correct tire in¯ation pressure, make sure that
the spare tire is stored securely. Push, pull, and then try
to rotate or turn the tire. If it moves, use the wheel
wrench/ratchet to tighten the cable. See
Changing a Flat
Tire on page 5-80.
Weatherstrip Lubrication
Silicone grease on weatherstrips will make them last
longer, seal better, and not stick or squeak. Apply
silicone grease with a clean cloth. During very cold,
damp weather more frequent application may be
required. See
Part D: Recommended Fluids and
Lubricants on page 6-19.
Manual Transmission Check
Check the transmission ¯uid level; add if needed. SeeManual Transmission Fluid on page 5-28. Check
for leaks. A ¯uid leak is the only reason for ¯uid loss.
Have the system inspected and repaired if needed.
Automatic Transmission Check
Check the transmission ¯uid level; add if needed. SeeAutomatic Transmission Fluid (Except Allison
Transmissionž) on page 5-23orAutomatic Transmission
Fluid (Allison Transmissionž) on page 5-26. A ¯uid
loss may indicate a problem. Check the system
and repair if needed.
6-13

Hydraulic Clutch System Check
Check the ¯uid level in the clutch reservoir. SeeHydraulic Clutch on page 5-29. A ¯uid loss in this
system could indicate a problem. Have the system
inspected and repaired at once.
At Least Once a Year
Key Lock Cylinders Service
Lubricate the key lock cylinders with the lubricant
speci®ed in Part D.
Body Lubrication Service
Lubricate all body door hinges, hood latch assembly,
secondary latch, pivots, spring anchor, release
pawl, tailgate hinge, tailgate linkage, tailgate handle
pivot points, latch bolt, fuel door hinge, locks and folding
seat hardware. Part D tells you what to use. More
frequent lubrication may be required when exposed to a
corrosive environment.
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
brake. See
Parking Brake on page 2-44if
necessary.
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) or NEUTRAL (N). If the starter works in
any other position, your vehicle needs service.
On manual transmission vehicles, put the shift lever
in NEUTRAL (N), push the clutch down halfway
and try to start the engine. The starter should work
only when the clutch is pushed down all the way
to the ¯oor. If the starter works when the clutch isn't
pushed all the way down, your vehicle needs
service.
6-14

Automatic Transmission Shift Lock
Control System 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. It should be parked on a level
surface.
2. Firmly apply the parking brake. See
Parking Brake
on page 2-44if necessary.
Be ready to apply the regular brake immediately if
the vehicle begins to move.3. With the engine off, turn the key to the RUN
position, but don't start the engine. Without applying
the regular brake, try to move the shift lever out
of PARK (P) with normal effort. If the shift lever
moves out of PARK (P), your vehicle needs service.
Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn
the ignition key to LOCK in each shift lever position.
·With an automatic transmission, the key should turn
to LOCK only when the shift lever is in PARK (P).
·With a manual transmission, the key should turn to
LOCK only when you press the key release button.
On all vehicles, the key should come out only in LOCK.
6-15

Parking Brake and Automatic
Transmission Park (P) Mechanism
Check
{CAUTION:
When you are doing this check, your vehicle
could begin to move. You or others could be
injured and property could be damaged. Make
sure there is room in front of your vehicle in
case it begins to roll. Be ready to apply the
regular brake at once should the vehicle begin
to move.Park on a fairly steep hill, with the vehicle facing
downhill. Keeping your foot on the regular brake, set the
parking brake.
·To check the parking brake's holding ability: With
the engine running and transmission in
NEUTRAL (N), slowly remove foot pressure from
the regular brake pedal. Do this until the vehicle is
held by the parking brake only.
·To check the PARK (P) mechanism's holding ability:
With the engine running, shift to PARK (P). Then
release the parking brake followed by the regular
brake.
Underbody Flushing Service
At least every spring, use plain water to ¯ush any
corrosive materials from the underbody. Take care to
clean thoroughly any areas where mud and other debris
can collect.
6-16

Part D: Recommended Fluids and
Lubricants
Fluids and lubricants identi®ed below by name, part
number or speci®cation may be obtained from your
dealer.
Usage Fluid/Lubricant
Engine OilEngine oil with the American
Petroleum Institute Certi®ed for
Gasoline Engines starburst symbol
of the proper viscosity. To determine
the preferred viscosity for your
vehicle's engine, see
Engine Oil on
page 5-16.
Engine Coolant50/50 mixture of clean, drinkable
water and use only
DEX-COOL
žCoolant. SeeEngine
Coolant on page 5-30.
Hydraulic Brake
SystemDelco Supreme 11 Brake Fluid or
equivalent DOT-3 brake ¯uid.
Windshield
Washer SolventGM Optikleen
žWasher Solvent or
equivalent.
Usage Fluid/Lubricant
Hydraulic
Clutch System
(5±Speed
Trans.)Hydraulic Clutch Fluid (GM Part No.
U.S. 12345347, in Canada
10953517, or equivalent DOT-3
brake ¯uid).
Hydraulic
Clutch System
(6±Speed
Trans.)Hydraulic Clutch Fluid. Use only GM
Part No. U.S. 88958860, in Canada
88901244.
Power Steering
SystemGM Power Steering Fluid (GM Part
No. U.S. 1052884, in Canada
993294, or equivalent).
Manual
Transmission
(5±Speed with
Low Gear,
RPO MW3)GM Goodwrench Synthetic Manual
Transmission Fluid (GM Part No.
U.S. 12346190, in Canada
10953477) or equivalent SAE
75W-85 GL-4 gear oil.
Manual
Transmission
(5±Speed
without Low
Gear, RPO
MG5)Synchromesh Transmission Fluid
(GM Part No. U.S. 12345349, in
Canada 10953465, or equivalent).
6-19

Usage Fluid/Lubricant
Manual
Transmission
(6±Speed)TranSyndŸ Synthetic Transmission
Fluid (GM Part No. U.S. 12378515,
in Canada 88900701).
Automatic
TransmissionDEXRON
ž-III Automatic
Transmission Fluid.
Key Lock
CylindersMulti-Purpose Lubricant, Superlube
(GM Part No. U.S. 12346241, in
Canada 10953474, or equivalent).
Floor Shift
LinkageLubriplate Lubricant Aerosol (GM
Part No. U.S. 12346293, in Canada
992723, or equivalent) or lubricant
meeting requirements of NLGI #2
Category LB or GC-LB.
Chassis
LubricationChassis Lubricant (GM Part No.
U.S. 12377985, in Canada
88901242, or equivalent) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
Front AxleSAE 80W-90 Axle Lubricant (GM
Part No. U.S. 1052271, in Canada
10950849 or equivalent).
Usage Fluid/Lubricant
Rear AxleSAE 75W-90 Synthetic Axle
Lubricant (GM Part No. U.S.
12378261, in Canada 10953455) or
equivalent meeting GM Speci®cation
9986115.
Rear Axle
(Steerable)Synthetic Axle Lubricant; use only
GM Part No. U.S. 12378557, in
Canada 88901362.
Do not add
friction modi®er.
Manual
Transfer CaseDEXRONž-III Automatic
Transmission Fluid.
Automatic
Transfer Case
(Four-Wheel
Drive)AUTO-TRAK II Fluid (GM Part No.
U.S. 12378508, in Canada
10953626).
Transfer Case
(All-Wheel
Drive)DEXRON
ž-III Automatic
Transmission Fluid.
6-20