1998 GMC ENVOY transmission

Driving On Grades
Reduce speed and shift to a 1owe.r gear Iwfow 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.
On
a long uphill grade, shift down and reduce your
speed to around
45 mph (70 km/h) to reduce the
possibility of engine and transmission overheating.
You should use DRIVE
(D) when towing a trailer.
Operating your vehicle
in DRIVE (D) when towing a
trailer
will minimize heat buildup and extend the life of
your transmission.
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 twn your
engine off imnlediately 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 (PI for a few minutes before turning
the engine off.
If you do get the overheat warning. see
”Engine Overheating”
in the Index.
Parking on Hills
You really should not park your vehicle, with 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.
-. 3
3.
4.
5.
Apply your regular brakes, but don’t shift into
PARK
(P) yet. Then turn your wheels into the curb
if facing downhill or into traffic if facing uphill.
Have someone place chocks under the trailer wheels.
When the wheel chocks are
in place, release the
regular brakes
until the chocks absorb the load.
Reapply the regular brakes. Then apply your parking
brake, and then shift into PARK
(P).
Release the regular brakes.
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When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
0 Start your engine;
Shift into a gear; and
0 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 adjustment. 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.
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Towing Your Vehicle
Try to have a GM dealer or a proressional towing
service tow your vehicle. See "Roadside Assistance"
in
the Index.
If your vehicle has been changed since it was
factory-new by adding things like fog lamps, aero
skirting, or special tires and wheels, these instructions
may not be correct.
Before you do anything, turn
on the hazard
warning flashers.
When you call,
tell the towing service:
0 That your vehicle has four-wheel drive.
0 The make, model and year of your vehicle.
0 Whether you can rnolle the shift lever for the
transmission and shift the transfer case.
0 If there was an accident, what was damaged.
When the towing service arrives,
let the tow operator
know that this manual contains these towing
instructions. The operator may want to see them.
To help avoid injury to you or others:
0 Never let passengers ride in a vehicle that is
Never tow faster than safe or posted speeds.
Never tow with damaged parts not
Never get under your vehicle after it has
Always use separate safety chains on each
0 Never use J-hooks. Use T-hooks instead.
being
towed.
fully secured.
been lifted by the tow truck.
side when towing
a vehicle.
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JTION:
A vehicle can fall from a car carrier if it isn’t
adequately secured. This can cause
a collision,
serious personal injury and vehicle damage. The
vehicle should be tightly secured with chains or
steel cables before it is transported.
Don’t use substitutes (ropes, leather straps,
canvas webbing, etc.) that can be cut by sharp
edges underneath the towed vehicle. Always use
T-hooks inserted in the T-hook slots. Never use
J-hooks. They will damage drivetrain and
suspension components.
When your vehicle is being towed, have the ignition key
turned
to the OFF position. The steering wheel should
be clamped
in a straight-ahead position with a clamping
device designed for towing service.
Do not use the
vehicle’s steering column lock for this. The transmission
should be in NEUTRAL
(N) and the transfer case
should be
in 2HI. The parking brake should be released.
If your vehicle has no electrical power, the electrical
solenoid lock
must be overridden to shift from
PARK (P) to NEUTRAL (N). Follow these steps:
1 I Remove the wood trim panel surrounding the base
2. Reach inside the console and find the white of the shift lever.
solenoid lever.
(ii
3. Push the solenoid
lever down.
4. While holding the solenoid lever in the unlock
position, press the shift lever button and shift into
NEUTRAL
(N).
5. Release the solenoid lever and replace the trim panel.
Don’t have your vehicle towed on the drive wheels
unless
you must. If the vehicle must be towed on the
drive wheels, be sure to follow the speed and distance
restrictions later
in this section or your transmission will
be damaged. If these limitations must be exceeded, then
the drive wheels have to be supported
on a dolly.
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Engine Fan Noise
This vehicle has a clutched engine cooling fan. When the
clutch is engaged, the fan spins faster to provide more air
to cool the engine. In most everyday driving conditions,
the clutch is
not engaged. This improves fuel economy and
reduces
fan noise. Under heavy vehicle loading, trailer
towing and/or high outside temperatures, the fan speed
increases when the clutch engages.
So you may hear an
increase in fan noise. This is normal and should not be
mistaken
as the transmission slipping or making extra
shifts. It is merely the cooling system functioning properly.
The fan will slow down when additional cooling is not
required and the clutch disengages.
You may
also hear this fan noise when you start the
engine. It will go away
as the fan clutch disengages.
If a Tire Goes Flat
It’s unusual for a tire to “blow out” while you’re driving,
especially if you maintain your tires properly.
If air goes
out of
a tire, it’s much more likely to leak out slowly.
But
if you should ever have a “blowout,” here are a few
tips about what to expect and what to do:
If
a front tire fails, the flat tire will create a drag that
pulls the vehicle toward that side.
Take your foot off the
accelerator pedal and grip
the steering wheel firmly.
Steer to maintain lane position, and then gently brake to
a stop well out of the traffic lane.
A rear blowout, particularly on a curve, acts much like a
skid and may require the same correction you’d use in a
skid. In any rear blowout, remove your foot from the
accelerator pedal. Get the vehicle under control by
steering the
way you want the vehicle to go. It may be
very bumpy and noisy, but you can
still steer. Gently
brake to
a stop -- well off the road if possible.
If a tire goes flat, the next part shows how to use your
iacking equipment to change
a flat tire safely. u Y a. c
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If You’re Stuck: In Sand, Mud,
Ice or Snow
What you don’t want to do when your vehicle is stuck is
to spin your wheels too fast. The method known as
“rocking” can help
you get out when you’re stuck, but
you must use caution.
A CAUTION:
If you let your tires spin at high speed, they can
explode, and you or others could be injured. And,
the transmission or other parts
of the vehicle can
overheat. That could cause an engine
compartment fire or other damage. When you’re
stuck, spin the wheels as little as possible. Don’t
spin the wheels above
35 mph (55 km/h) as shown
on the speedometer.
I
NOTICE:
Spinning your wheels can destroy parts of your
vehicle as well as the tires. If you spin the wheels
too fast while shifting your transmission back
and forth, you can destroy your transmission.
For information about using tire chains on your vehicle,
see “Tire Chains”
in the Index.
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Rocking Your Vehicle To Get It Out
First, turn your steering wheel left and right. That will
clear
the area around your front wheels. Shift the transfer
case into
4HI. Then shift back and forth between
REVERSE
(R) and a forward gear, spinning the wheels as
little as possible. Release the accelerator pedal while you shift, and press lightly
on the accelerator pedal when the
transmission is in gear.
If that doesn’t get you out after a
few tries,
you may need to be towed out. Or, you can use
your recovery
hooks. If you do need to be towed out, see
“Towing Your Vehicle”
in the Index.
Using the Recovery Hooks
Your vehicle is equipped with recovery hooks. The
recovery hooks are provided at the front
of your vehicle.
You may need
to use them if you’re stuck off-road
and need
to be pulled to some place where you can
continue driving.
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Section 6 Service and Appearance Care
Here you will find information about the care of your vehicle. This section begins with service and fuel information,
and then
it shows how to check important fluid and lubricant levels. There is also technical information about your
vehicle, and a part devoted
to its appearance care.
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6-3
6-5
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6-8
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10
6-14
6- 15
6-19
6-20
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6- 24
6-25
6-25
6-26
6-
2’7
Service
Fuel
Fuels in Foreign Countries
Filling Your Tank
Filling a Portable
Fuel Container
Checking Things Under the Hood
Engine Oil
Air Cleaner
Automatic Transmission Fluid
Rear Axle
Four- Wheel Drive
Engine Coolant
Radiator Pressure Cap
Thermostat
Power Steering Fluid
Windshield Washer Fluid
Brakes Battery
Bulb Replacement
Windshield Wiper Blade Replacement
Tires
Appearance Care
Cleaning the Inside
of Your Vehicle
Care of Safety Belts
Cleaning the Outside of Your Vehicle
Appearance Care Materials Chart
Vehicle Identification Number (VIN)
Service Parts Identification Label
Electrical System
Replacement Bulbs
Capacities and Specifications
Air Conditioning Refrigerants
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