transmission GMC SIERRA 2008 Repair Manual

Tire Terminology and Denitions
Air Pressure:The amount of air inside the
tire pressing outward on each square inch of the
tire. Air pressure is expressed in pounds per
square inch (psi) or kilopascal (kPa).
Accessory Weight
:This means the combined
weight of optional accessories. Some examples of
optional accessories are, automatic transmission,
power steering, power brakes, power windows,
power seats, and air conditioning.
Aspect Ratio
:The relationship of a tire’s height
to its width.
Belt
:A rubber coated layer of cords that is
located between the plies and the tread. Cords
may be made from steel or other reinforcing
materials.
Bead
:The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the rim.
Bias Ply Tire
:A pneumatic tire in which the plies
are laid at alternate angles less than 90 degrees
to the centerline of the tread.Cold Tire Pressure
:The amount of air pressure
in a tire, measured in pounds per square inch
(psi) or kilopascals (kPa) before a tire has built up
heat from driving. SeeInflation - Tire Pressure
on page 5-74.
Curb Weight
:The weight of a motor vehicle with
standard and optional equipment including the
maximum capacity of fuel, oil, and coolant, but
without passengers and cargo.
DOT Markings
:A code molded into the sidewall
of a tire signifying that the tire is in compliance
with the U.S. Department of Transportation (DOT)
motor vehicle safety standards. The DOT code
includes the Tire Identication Number (TIN),
an alphanumeric designator which can also identify
the tire manufacturer, production plant, brand, and
date of production.
GVWR
:Gross Vehicle Weight Rating. See
Loading Your Vehicle on page 4-36.
GAWR FRT
:Gross Axle Weight Rating for
the front axle. SeeLoading Your Vehicle
on page 4-36.
5-71

Fuses Usage
1 Right Trailer Stop/Turn Lamp
2Electronic Suspension Control,
Automatic Level Control Exhaust
3 Left Trailer Stop/Turn Lamp
4 Engine Controls
5Engine Control Module, Throttle
Control
6 Trailer Brake Controller
Fuses Usage
7 Front Washer
8 Oxygen Sensor
9 Antilock Brakes System 2
10 Trailer Back-up Lamps
11 Driver Side Low-Beam Headlamp
12 Engine Control Module (Battery)
13Fuel Injectors, Ignition Coils
(Right Side)
14Transmission Control Module
(Battery)
15 Vehicle Back-up Lamps
16Passenger Side Low-Beam
Headlamp
17 Air Conditioning Compressor
18 Oxygen Sensors
19 Transmission Controls (Ignition)
20 Fuel Pump
21 Fuel System Control Module
22 Not Used
23 Not Used
24Fuel Injectors, Ignition Coils
(Left Side)
25 Trailer Park Lamps
26 Driver Side Park Lamps
5-127

ApplicationCapacities
English Metric
2500 Series Standard Box 26.0 gal 98.0 L
2500 Series and 3500 Series Long Box 34.0 gal 128.7 L
3500 Series Chassis Cab 50.0 gal 189.0 L
3500 Chassis Cab – Front Tank 27.0 gal 102.0 L
3500 Chassis Cab – Rear Tank 23.0 gal (if equipped) 87.0 L
Transmission Fluid (Pan Removal and Filter Replacement)
Auto 4-Speed Transmission 4L60-E Electronic
Transmission5.0 qt 4.7 L
Auto 4-Speed Transmission 4L70-E Super Duty
Transmission5.0 qt 4.7 L
Auto 6-Speed Transmission 6L80-E 6.0 qt 5.7 L
Auto 6-Speed Transmission 6L90-E 6.3 qt 6.0 L
Auto 6-Speed Transmission Allison 7.4 qt 7.0 L
Transfer Case Fluid 1.6 qt 1.5 L
Wheel Nut Torque 140 ft lb 190Y
After rell, the level must be rechecked. Add enough engine coolant so that the uid is within the proper
operating range.
5-131

Engine Specications
Engine VIN Code Transmission Spark Plug Gap
4.3L V6 X Automatic 0.060 in (1.52 mm)
4.8L V8 C Automatic 0.040 in (1.01 mm)
5.3L V8 Flexible Fuel with
Active Fuel Management™
(Iron Block)0 Automatic 0.040 in (1.01 mm)
5.3L V8 Flexible Fuel with
Active Fuel Management™
(Aluminum Block)3 Automatic 0.040 in (1.01 mm)
5.3L V8 with Active Fuel
Management™
(Aluminum Block)M Automatic 0.040 in (1.01 mm)
5.3L V8 with Active Fuel
Management™ (Iron Block)J Automatic 0.040 in (1.01 mm)
6.0L V8 (Iron Block) K Automatic 0.040 in (1.01 mm)
6.0L V8 with Active Fuel
Management™
(Aluminum Block)Y Automatic 0.040 in (1.01 mm)
5-132

MaintenanceI— Use MaintenanceIif the
CHANGE ENGINE OIL SOON message comes
on within 10 months since the vehicle was purchased
or MaintenanceIIwas performed.MaintenanceII— Use MaintenanceIIif the previous
service performed was MaintenanceI. Always use
MaintenanceIIwhenever the message comes on
10 months or more since the last service or if the
message has not come on at all for one year.
Scheduled Maintenance
Service MaintenanceIMaintenanceII
Change engine oil and lter. SeeEngine Oil (Gasoline Engine) on page 5-15.
Reset oil life system. SeeEngine Oil Life System on page 5-18.An Emission
Control Service.••
Allison Transmission
®only: Replace external transmission lter at the rst
maintenance service performed on the vehicle.
Lubricate chassis components.See footnote #.••
Visually check for any leaks or damage.See footnote (j).••
Inspect engine air cleaner lter or change indicator (if equipped). If
necessary, replace lter. SeeEngine Air Cleaner/Filter (Gasoline Engines) on
page 5-19.See footnote (p).•
Rotate tires and check ination pressures and wear. SeeTire Inspection and
Rotation on page 5-81and “Tire Wear Inspection” inAt Least Once a Month
on page 6-12.••
Inspect brake system.See footnote (a).••
Check engine coolant and windshield washer uid levels and add uid
as needed.••
6-5

Scheduled Maintenance (cont’d)
Service MaintenanceIMaintenanceII
Perform any needed additional services. See “Additional Required Services”
in this section.••
Inspect suspension and steering components.See footnote (b).•
Inspect engine cooling system.See footnote (c).•
Inspect wiper blades.See footnote (d).•
Inspect restraint system components.See footnote (e).•
Lubricate body components.See footnote (f).•
Check transmission uid level and add uid as needed.•
Inspect shields, vehicles with diesel engine or with GVWR above
10,000 lbs (4 536 kg) only.See footnote (n).•
6-6

Additional Required Services
(Gasoline Engine)
This maintenance section applies to vehicles with a
gasoline engine. If your vehicle has a diesel engine,
see the maintenance schedule section in the
DURAMAX
®Diesel manual.The following services should be performed at the
rst maintenance service (IorII) after the indicated
miles (kilometers) shown for each item.
Additional Required Services
Service and Miles (Kilometers)25,000
(40 000)50,000
(80 000)75,000
(120 000)100,000
(160 000)125,000
(200 000)150,000
(240 000)
Inspect fuel system for damage
or leaks.• •••••
Inspect exhaust system for loose
or damaged components.• •••••
Vehicles without a lter restriction
indicator: Replace engine air cleaner
lter. SeeEngine Air Cleaner/Filter
(Gasoline Engines) on page 5-19.•••
Change automatic transmission
uid and lter (severe service).
See footnote (h).•••
Change automatic transmission
uid and lter (normal service).•
6-7

(e)Make sure the safety belt reminder light and safety
belt assemblies 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 see Checking
the Restraint Systems on page 1-87.
(f)Lubricate all key lock cylinders, body door hinges,
hood latch assembly, secondary latch, pivots, spring
anchor, release pawl, tailgate hinges, tailgate linkage,
tailgate handle pivot points, latch bolt, fuel door
hinge, locks, and folding seat hardware. More frequent
lubrication may be required when exposed to a
corrosive environment. Applying silicone grease on
weatherstrips with a clean cloth will make them
last longer, seal better, and not stick or squeak.
(g)Check vent hose at transfer case for kinks and
proper installation. Check to be sure vent hose
is unobstructed, clear, and free of debris.(h)Change automatic transmission fluid and filter if the
vehicle Gross Vehicle Weight Rating (GVWR) is
over 8600 lbs 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.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery
service.
(i)Drain, flush, and refill cooling system. This service can
be complex; you should have your dealer/retailer perform
this service. See Engine Coolant on page 5-28for what to
use. Inspect hoses. Clean radiator, condenser, pressure
cap, and ller neck. Pressure test the cooling system and
pressure cap.
(j)A fluid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired and
the fluid level checked. Add fluid if needed.
(k)Inspect system. Check all fuel and vapor lines and
hoses for proper hook-up, routing, and condition. Check
that the purge valve, if the vehicle has one, works
properly. Replace as needed.
6-10

At Least Once a Year
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. SeeParking Brake on page 2-49.
Do not use the accelerator pedal, and be ready to
turn off the engine immediately if it starts.
3. Try to start the engine in each gear. The vehicle
should start only in PARK (P) or NEUTRAL (N).
If the vehicle starts in any other position, contact
your dealer/retailer for service.
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. SeeParking Brake
on page 2-49.
Be ready to apply the regular brake immediately if
the vehicle begins to move.
3. With the engine off, turn the ignition to ON/RUN,
but do not 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), contact your dealer/retailer
for service.
6-13

Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn
the ignition to LOCK/OFF in each shift lever position.
The ignition should turn to LOCK/OFF only
when the shift lever is in PARK (P).
The ignition key should come out only in
LOCK/OFF.
Contact your dealer/retailer if service is required.
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 the 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.
Contact your dealer/retailer if service is required.
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.
6-14