1993 GMC SIERRA automatic transmission

Featwes & Contmk
The front axle portion of the indicator diagram will light up when you shift into
four-wheel drive.
A slight delay between shifting and the indicator’s lighting is
normal.
If the indicator does not light up, or if the front axle light does not go
out after you shift out of four-wheel drive, have your dealer check your
system.
When your headlights or parking lights are on, rotate the dial\

to the right of
your headlight switch up
to brighten, or down to dim, your transfer case
indicator light.
Transfer Case Shift Positions
2H (High): This setting is for driving in most street and highway situations.
Your front axle is not engaged in two-wheel drive.
4H (High): This setting engages your front axle to help drive your vehicle.
Use
4H when you need extra traction, such as on wet or icy roads, or in
most
off -road situations.
N (Neutral): Shift to this setting only when your vehicle needs to be towed or
when using a power take
off.
4L (Low): This setting also engages your front axle to give you extra traction,
but should be used only for off-road or on extremely slippery surfaces.
You can shift from
2H to 4H or from 4H to 2H while the vehicle is moving.
Your front axle will engage faster
if you take your foot off of the accelerator
for a few seconds after you shift. In extremely cold weather it may be
necessary to stop or slow the vehicle to shift out of
2H.
To shift into or out of 4L or N (Neutral):
1. Slow the vehicle to a roll, about 3 mph (5 kmlh) and shift your
2. Shift the transfer case shift lever in one continuous motion.
transmission into neutral.
Don’t pause in
N (Neutral) as you shift the transfer case into 4L, or your
aears could clash.
Kernember that driving
in 4H or 4L may reduce fuel economy. Also, driving in
four-wheel drive on dry pavement could cause your tires to wea\
r faster and
make your transfer case harder
to shift.
Front Axle Locking Feature
The front axle locks and unlocks automatically when you shift the transfer
case.
A slight delay for the axle to lock or unlock is normal. If the outside
temperature is very hot, or the vehicle has been used under hard driving
conditions, there may be a slight delay for the axle to unlock.
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AM470053
If there is no curb when you’re parking uphill, turn the wheels to the right.
If there is no curb when you’re parking uphill on the left side of a one-way
street, your wheels should be turned to the left.
Torque Lock (Automatic Transmission)
If you are parking on a hill and you don’t shift your tra\
nsmission into P
(Park) properly, the weight of the vehicle may put too much force on the
parking pawl in the transmission. You may find it difficult to pull the shift lever
out of
P (Park). This is called “torque lock.” To prevent torque lock, always
be sure to shift into
P (Park) before you leave the driver’s seat. To find out
how, see “Shifting Into
P (Park)” in the Index.
When you are ready to drive, move the shift lever out
of P (Park) BEFORE
you release the parking brake.
If “torque lock” does occur, you may need to have another vehicle push
yours a little uphill to take some of the pressure from the transmission,
so
you can pull the shift lever out of P (Park).
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Your Driving and the Road
drivers behind you are seeing your signal when they are not. It’s important to
check occasionally to be sure the trailer bulbs are still working.
Driving on Grades
Reduce speed and shift to a lower gear before you start down 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
45 mph (70
kmlh) or less to reduce the possibility of engine and transmission overheating.
IT you have an automatic transmission, you should use D (or, as you need to,
a lower gear) when towing a trailer. Operating your vehicle i\
n
D when towing
a trailer will minimize heat buildup and extend the life of your transmission.
Or, if you have a manual transmission with fifth gear and you are towing a
trailer, it’s better not to use fifth gear. Just drive in fourth gear
(or, as you
need to, a lower gear).
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. Apply your regular brakes, but don’t shift into P (Park) yet, or into gear
2. Have someone place chocks under the trailer wheels.
for a manual transmission.
3. When the wheel chocks are
in place, release the regular brakes until the
chocks absorb the load.
4. Reapply the regular brakes. Then apply your parking brake, and \
then
5. If you have a four-wheel-drive vehicle, be sure the transfer case is in a
6. Release the regular brakes.
shift
to
P (Park), or R (Reverse) for a manual transmission.
drive gear-not in
N (Neutral).
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CAUTION
It can be dangerous to get out of your vehicle if the shift lever is not
fully in
P (Park) with the parking brake firmly set. Your vehicle can
roll.
If you have left the engine running, the vehicle can move suddenl\
y.
You
or others could be injured. To be sure your vehicle won’t move,
when you’re on fairly level ground, use the steps that follow.
If you have four-wheel drive and your transfer case is in N (Neutral),
your vehicle will be free to
roll, even if your shift lever is in P (Park).
So, be sure the transfer case is in a drive gear-not in N (Neutral).
If you are parking on a hill, or if you’re pulling a trailer, also see
“Parking On Hills” in the Index.
When You Are Ready to Leave After Parklng 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 To wing
Your vehicle will need service more often when you’re pulling a trailer. See
the Maintenance Schedule for more on this. Things that are esp\
ecially
important in trailer operation are automatic transmission fluid (don’t overfill),
engine oil, axle lubricant, belts, cooling system, and brake ad\
justment. 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.
mailer Wiring Harness
See “Trailer Wiring Harness’’ in the Index.
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Using a Transfer Case Mounted Power Take-Off (Manual
Transmission)
1. Set the parking brake.
2. Shift the transfer case into N (Neutral).
3. Hold the clutch pedal down. If the vehicle will remain in the same place,
4. Engage the power take-off.
shift the transmission into the highest
gear.
If you are going to drive the vehicle, shift the transmission into the gear
you want. Then shift the transfer case into the range you wan\
t, apply
the regular brakes and release the parking brake.
5 Release the clutch (and the regular brakes) as you normally \
would.
Using a Transfer Case Mounted Power Take-Off (Automatic
Transmission)
When you release the clutch, the power take-off will start.
1 I Set the parking brake.
2. Shift the transfer case into N (Neutral).
3. Shift the transmission into N (Neutral).
4. Engage the power take-off.
If you are going to drive the vehicle, shift the transfer case into the
range you want. Then apply the regular brakes and release the \
parking
brake.
5. Shift the transmission to D (Drive) to start the power take-off.
6. Release the regular brakes to drive the vehicle.
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Pmbkms on the Road
not be able to get enough power from a single battery in another vehicle
to start your diesel engine.
If your vehicle has more than one battery, use the battery that’\
s closest
to the starter-this will reduce electrical resistance.
2. Get the vehicles close enough so the jumper cables can reach, but be
sure the vehicles aren’t touching each other.
If they are, it could cause a
ground connection you don’t want. You wouldn’t be able
to start your
vehicle, and the bad grounding could damage the electrical syst\
ems.
You could be injured
if the vehicles roll. Set the parking brake firmly
manual transmission in
N (Neutral).
If you have a four-wheel-drive vehicle, be sure the transfer c\
ase is
not in
N (Neutral).
1 on each vehicle. Put an automatic transmission in P (Park) or a
3. Turn off the ignition on both vehicles. Turn off all lights that aren’t need-
ed, and radios. This will avoid sparks and help save both bat\
teries. And
it could save your radio!
ou leave your radio on, it could be badly damaged. The repairs
r.,Jldn’t be covered by your warranty. I
4. Open the hoods and locate the batteries.
Find the positive
(t) and negative (-) terminals on each battery.
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Service & 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 section devoted to its appearance care
.
Service ........................................................................\
........................................... 6-3
Fuel (Gasoline Engines)
........................................................................\
............... 6-4
Diesel Fuel Requirements and Fuel System
...................................................... 6-6
Checking Things Under the Hood
..................................................................... 6-17
Hood Release
........................................................................\
.......................... 6-18
Cleaning Your Diesel Engine
........................................................................\
.. 6-19
Noise Control System
........................................................................\
............. 6-19
Engine Oil (Except Diesel)
........................................................................\
..... 6.20
Engine Oil (Diesel Engines)
........................................................................\
... 6-26
Air Cleaner
........................................................................\
............................... 6-31
Automatic Transmission Fluid
........................................................................\
. 6-33
Manual Transmission Fluid
........................................................................\
..... 6-36
Hydraulic Clutch
........................................................................\
....................... 6-37
Transfer Case
........................................................................\
.......................... 6-39
Front Axle ........................................................................\
................................. 6-40
Rear Axle
........................................................................\
................................. 6-41
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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. Refer
to the Maintenance Schedule to determine when
to change your fluid. See "Scheduled Maintenance Services" in the \
Index.
How to Check:
Because this operation can be a little difficult, you may choose to have this
done at a General Motors 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.
I Too much or too little fluid can damage your transmission. Too much can
nean that some of the fluid could come out and fall on hot engine parts,
itarting
a fire. Be sure to get an accurate reading if you check your
ransmission ftuid.
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).
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 must be at normal operating temperature,
which is 180°F
to 200°F (82°C to 93°C).
To check the transmission fluid hot: Get the vehicle warmed up by driving
about
15 miles (24 km) when outside temperatures are above 50°F (1 0°C). If
it's colder than
50°F (lO°C), drive the vehicle in D (3rd gear) until the engine
temperature gage moves and then remains steady for ten minutes. Then
follow the hot check procedures.
To check transmission fluid cold: A cold check is made after the vehicle
has been sitting for eight hours or more with the engine
off and is used only
as a reference. Let the engine run at idle for five minutes
if outside
temperatures are 50°F (10°C) or more.
If it's colder than 50°F (lO"C), you
may have
to idle the engine longer. A hot check must follow when fluid is
added during a cold check.
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