2003 CHEVROLET ASTRO transmission

If yours was built with trailering options, as many are,
it’s ready for heavier trailers. But trailering is different
than just driving your vehicle by itself. Trailering means
changes in handling, durability and fuel economy.
Successful, safe trailering takes correct equipment,
and it has to be used properly.
That’s the reason for this part. In it are many time-tested,
important trailering tips and safety rules. Many of these
are important for your safety and that of your passengers.
So please read this section carefully before you pull
a trailer.
If You Do Decide To Pull A Trailer
If you do, here are some important points:
e
e
There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
your rig will
be legal, not only where you live
but also where you’ll be driving.
A good source for
this information can be state or provincial police.
Consider using
a sway control if your trailer will
weigh 2,000 Ibs
(900 kg) or less. You should
always use a sway control
if your trailer will weigh
more than 2,000
Ibs (900 kg). You can ask a
hitch dealer about sway controls.
e
e
e
Don’t tow a trailer at all during the first 500 miles
(800 km) your new vehicle is driven. Your engine,
axle or other parts could be damaged.
Then, during the first
500 miles (800 km) that you
tow a trailer, don’t drive over
50 mph (80 km/h)
and don’t make starts at full throttle. This helps your
engine and other parts of your vehicle wear in at
the heavier loads.
You can tow in
DRIVE (D). You may want to shift
the transmission to THIRD (3) or,
if necessary, a
lower gear selection
if the transmission shifts
too often (e.g., under heavy loads and/or hilly
conditions).
Three important considerations have to do with weight:
the weight of the trailer,
the weight of the trailer tongue
and the weight on your vehicle’s tires.
4-32

Tow/Haul Mode
The tow/haul mode is a feature that assists when pulling
a heavy trailer. The purpose of the tow/haul mode is:
e to reduce the frequency of shifts when pulling a
heavy trailer.
to provide the same shift feel when pulling a heavy
trailer as when the vehicle is unloaded.
to reduce the need to change throttle position when
pulling a heavy trailer.
This feature is turned on or off by pressing a button on
the column shift lever. When the feature
is on, a
light on the instrument panel will illuminate to indicate
that the tow/haul mode has been selected.
See
Tow/Haul Mode Light on page 3-36. The tow/haul
mode is automatically turned
off each time the vehicle
is started.
The tow/haul mode is most effective when the vehicle
and trailer combined weight is at least
75% of the Gross
Vehicle Weight Rating (GVWR) and the maximum
trailer weight rating for the vehicle. The tow/haul
mode for hauling a heavy trailer is most
useful under the following conditions:
When driving through hilly terrain at speeds below
55 mph
(88 km/h).
When driving in low speed or stop and go traffic
below
55 mph (88 km/h).
When driving in parking lots.
Operating in the tow/haul mode when not pulling a
heavy trailer will not cause damage to the vehicle,
but you may experience reduced fuel economy
and undesirable petformance from the engine and
transmission. The tow/haul mode should be used only
when pulling a heavy trailer.
Weight of the Trailer
How heavy can a trailer safely be?
It depends on how you plan to use your rig. For example,
speed, altitude, road grades, outside temperature and
how much your vehicle is used to pull a trailer are all
important. And, it can also depend on any special
equipment that you have on your vehicle.
4-33

Driving On Grades Parking on Hills
Reduce speed and shift to a lower gear before you start
down a long or steep downgrade.
If you don’t shift
down, you might have to use your brakes
so much that
they would get hot and no longer work well.
You can tow in DRIVE (D). You may want to shift the
transmission to THIRD
(3) or, if necessary, a lower gear
selection
if the transmission shifts too often (e.g., under
heavy loads and/or hilly conditions).
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes.
If you turn your
engine
off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar to engine overheating.
To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in PARK
(P) for a
few minutes before turning the engine
off. If you do get
the overheat warning, see
Engine Overheating on
page
5-3 1.
You really shoul tot park your vehicle, ith a
trailer attached, on a hill.
If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.
But if you ever have to park your rig on a hill, here’s
how to do it:
1. Apply your regular brakes, but don’t shift into
2. Have someone place chocks under the trailer
3. When the wheel chocks are in place, release the
4. Reapply the regular brakes. Then apply your PARK (P) yet.
wheels. regular brakes until the chocks absorb the load.
parking brake, and shift to PARK (P).
5. Release the regular brakes.
4-39

When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
start your engine,
shift into a gear, and
release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the
chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you’re
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission fluid (don’t overfill),
engine oil, axle lubricant, belt, cooling system and
brake system. Each
of these is covered in this manual,
and the Index will help you find them quickly.
If you’re
trailering, it’s a good idea to review these sections
before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
4-40

Section 5 Service and Appearance Care
Service .......................................................... -5-3
Doing Your Own Service Work
......................... 5-3
Adding Equipment to the Outside of
Your Vehicle
.............................................. 5-4
Fuel ................................................................ 5.5
Gasoline Octane ........................................... -5-5
Gasoline Specifications .................................... 5.5
California Fuel ............................................. -56
Additives
....................................................... 5.6
Fuels in Foreign Countries
............................... 5.7
Filling Your Tank
............................................ 5-8
Filling a Portable Fuel Container
..................... 5-10
Checking Things Under the Hood .................... 5-1 1
Hood Release .............................................. 5.11
Engine Compartment Overview
...................... 5.14
Engine Oil
................................................... 5.15
Engine Cover ................. .... ........ 5.20
Engine Air Cleaner/Filter
................. ........ 5.24
Automatic Transmission Fluid
...................... 5.25
Engine Coolant ............................................. 5.28
Radiator Pressure Cap
.................................. 5.30
Engine Overheating
....................................... 5.31
Cooling System
............................................ 5.33
Engine Fan Noise
......................................... 5.39
Power Steering Fluid
..................................... 5.40
Windshield Washer Fluid
................................ 5.41 Brakes
........................................................ 5.42
Battery
........................................................ 5-46
Jump Starting
............................................... 5-47
All-Wheel Drive .............................................. 5-52
Rear Axle ....................................................... 5-53
Front Axle ...................................................... 5-54
Bulb Replacement .......................................... 5-55
Halogen Bulbs .............................. ..... 5-55
Headlamps .................................. ..... 5-55
Front Turn Signal Lamps ............................... 5-59
Replacement Bulbs
....................................... 5-61
Windshield Wiper Blade Replacement .............. 5-62
Tires .............................................................. 5.63
Inflation
- Tire Pressure ................................ 5-64
Tire Inspection and Rotation
........................... 5-64
When It
Is Time for New Tires ....................... 5-66
Buying New Tires
......................................... 5-66
Uniform Tire Quality Grading
.......................... 5-67
Wheel Alignment and Tire Balance
.................. 5-69
Wheel Replacement
...................................... 5-69
Tire Chains
.................................................. 5-70
If a Tire Goes Flat ........................................ 5.70
Changing a Flat Tire ..................................... 5.71
Compact Spare Tire ...................................... 5-82
Taillamps
.................................................... 5-60
5- 1

A. Windshield Washer Fluid
B. Engine Coolant
C. Engine
Oil Dipstick
D. Transmission Dipstick
E. Engine Air Cleaner/Filter
F. Engine Oil Fill
G. Brake Master Cylinder Reservoir
H. Power Steering Fluid Reservoir
I. Battery
Engine Oil
It is important to keep engine oil at the proper level. The engine oil dipstick has a yellow ring and is located
near the center of the engine compartment. See
Engine
information on location.
Checking Engine Oil Compartment Overview on page 5- 14 for more
It’s a good idea to check your engine oil every time
you
get fuel. In order to get an accurate reading, the oil Turn off the engine and give the oil several minutes to
must be warm and the vehicle must be on level ground. drain back into the
Oil pan. If YOU don’t, the oil dipstick
might not show the actual level.
Pull out the dipstick and clean it with a paper towel or
cloth, then push it back in all the way. Remove it again,
keeping the tip down, and check the level.
5-1 5

Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmission fluid
level is when the engine oil is changed.
Change both the fluid and filter every
15,000 miles
(25
000 km) if the vehicle is mainly driven under one or
more of these conditions:
In heavy city traffic where the outside temperature
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery
If you do not use your vehicle under any of these
conditions, change the fluid and filter every
50,000 miles (83 000 km).
See
Part A: Scheduled Maintenance Services on
page
6-4.
regularly reaches 90°F (32°C) or higher.
service.
How to Check
Because this operation can be a little difficult, you may
choose to have this done at the dealership service
department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.
Notices Too much or too little fluid can damage
your transmission.
Too much can mean that some
of the fluid could come out and fall on hot engine
part or exhaust system parts, starting a fire.
Too little fluid could cause the transmission to
overheat. Be sure to get an accurate reading if you
check your transmission fluid.
Wait at least 30 minutes before checking the
transmission fluid level
if you have been driving:
When outside temperatures are above 90°F (32°C).
0 At high speed for quite a while.
In heavy traffic
- especially in hot weather.
While pulling a trailer.
To get the right reading, the fluid should be at normal
operating temperature, which is 180°F to 200°F
(82°C to 93°C).
5-25

Get the vehicle warmed up by driving about 15 miles
(24 km) when outside temperatures are above 50°F
(10°C).
If it's colder than 50°F (IOOC), drive the vehicle
in THIRD
(3) until the engine temperature gage
moves and then remains steady for
10 minutes.
A cold fluid check can be made after the vehicle has
been sitting for eight hours or more with the engine
off,
but this is used only as a reference. Let the engine
run at idle for five minutes
if outside temperatures are
50°F (1 OOC) or more.
If it's colder than 50°F (IOOC), you may have to idle the
engine longer. Should the fluid level be low during
this cold check, you
must check the fluid hot before
adding fluid. Checking the fluid hot
will give you a more
accurate reading of the fluid level.
Checking the Fluid Level
Prepare your vehicle as follows:
Park your vehicle on a level place. Keep the engine
running.
With the parking brake applied, place the shift lever
in PARK (P).
With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, position the shift
lever in PARK
(P).
Let the engine run at idle for three minutes or more. Then, without
shutting
off the engine, follow these steps:
The transmission dipstick has a red handle and is
located near the center of the engine compartment
behind the air cleaner. See
Engine Compartment
Overview on page 5-14
for more information on location.
1. Flip the handle up and then pull out the dipstick
and wipe it with a clean rag or paper towel.
2. Push it back in all the way, wait three seconds and
then pull
it back out again.
5-26