2020 CHEVROLET LOW CAB FORWARD automatic transmission

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
204 Driving and Operating
Actions that Can Lead to a Breakdown with an Automatic Transmission
Actions that can lead to a breakdownBreakdown symptoms
Stopping the vehicle on an uphill road with the selector lever in a position
other than R, N, or P, the accelerator pedal pressed, and the brakes not
applied. The transmission fluid overheats.
Continuously pressing the accelerator pedal and brake pedal at the same
time while the vehicle is in a position other than N or P.
Placing the selector lever into any gear with the accelerator pedal pressed
and the engine speed high. The transmission gears are
overloaded.
Placing the selector lever into P before the vehicle has completely stopped. The parking mechanism will be
damaged.
Turning off the engine control switch while driving. The transmission is not properly
lubricated.
Driving with the selector lever in the N position on a long downward slope
(this is dangerous due to the lack of engine brake).

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Driving and Operating 205
Selector Lever
Move the selector lever (2) to make
a shift into each gear position.
P (Parking) :Used when the
vehicle is parked or when starting
the engine. The P position is to be
used with the parking brake. The P
and N positions are the two
positions in which the engine can be
started.
R (Reverse) : Used when backing
up the vehicle. Bring the truck to a
complete stop before moving the
selector to the R position. N (Neutral) :
Can be used when
starting the engine, but for safety,
get in the habit of starting the
engine in the P position. The N
position is used should it become
necessary to tow your truck.
D (Drive) : The D position is for all
normal forward driving. The system
automatically selects the gear
according to the vehicle speed.
Press the overdrive off switch (3) to
switch to the overdrive ON position
for greater fuel economy.
2 (Second) : May be used when
driving on downhill roads or when
the engine brake is required. Select
the 2 position at speeds below
40 km/h (25 MPH) when traveling
down a moderate grade. Return the
selector to the D position for normal
driving.
1 (Low) : Used on steep downhill
roads or when strong engine
braking is required. Return the
selector to the D position for normal
driving.
{Warning
When pulling away, always
visually check the position of the
selector lever for safety.
Only push the button for gear
selection when necessary.
Pushing the button unnecessarily
may result in unintended gear
selection.
Never move the selector to the P
position when the truck is in
motion.
Do not run the vehicle with the
transmission in neutral. Not only
will the engine brake not function,
but the transmission will also be
damaged. You and others could
be seriously injured.
When repeatedly shifting between
forward and reverse gears for a
multiple-point turn, firmly press the
brake pedal and confirm that the
vehicle is completely stopped before
operating the selector lever.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
206 Driving and Operating
For safety reasons, the shift lock
system operates to prevent shifting
of the selector lever to any position
other than P unless the brake pedal
is pressed and the starter switch is
in the ON position. When pulling
away, be sure to keep the brake
pedal pressed as you operate the
selector lever. SeeDriver
Information Center (DIC) 070,
Overdrive Off Light 066, Automatic
Transmission 0196, and Automatic
Transmission Shift Lock Control
Function Check 0264.
Overdrive Off
Overdrive Off Switch
Diesel vehicles have two overdrive
gears (5th and 6th). These two high
speed gears provide increased road
speed, low running noise and
outstanding fuel efficiency.
Take advantage of overdrive
whenever possible.
.
Use the overdrive during normal
driving. When driving down long
downhill roads that require the
engine brake, or when driving on mountain roads or through city
centers, release the overdrive.
Doing so will reduce the number
of gear changes making the ride
smoother.
. If your vehicle is traveling at a
speed exceeding
101 km/h (63 MPH), it is not
possible to downshift from 6th
gear to 5th gear.
. If your vehicle is traveling at a
speed exceeding
78 km/h (49 MPH), it is not
possible to downshift from 5th
gear to 4th gear.
Overdrive Off Switch : Under
normal circumstances, press the
overdrive off switch (3) to turn the
overdrive OFF (the overdrive off
indicator light comes on).
Press the switch again to release
the overdrive off (the overdrive off
indicator light goes off). See
Overdrive Off Light 066.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Driving and Operating 207
Overdrive Off Indicator Light
Indicator lightFunction Usage conditions
Goes Off. 6-Speed (4-speed + overdrive) automatic
change (Overdrive ON). Use under normal driving conditions.
Comes On. 4-speed automatic change, but no change to
overdrive (overdrive OFF). Used when a light engine brake is required.
Doing so will reduce the number of gear
changes making the ride smoother on roads
that have many hills.
. During cold weather, the
transmission may not shift to the
5th or 6th gear (overdrive) until
the engine warms up.
. Even if the engine is stopped
with the overdrive OFF, the
overdrive will be ON the next
time the engine is started.
Brakes
Antilock Brake
System (ABS)
Wheels may be locked and slip
during sudden braking or braking on
a slippery road surface such as a
snowy road. ABS is a device to
prevent the wheels from locking by
detecting a slippery condition during
braking and securing the directional
stability and handling stability of the
vehicle. ABS only assists in limited
road conditions and will not prevent
a crash if you exceed safe driving
speeds for road conditions. Always
drive safely.
{Warning
The braking distance on slippery
road surfaces is longer than that
on a normal dry paved road even
with an ABS-equipped vehicle. In
addition the braking distance can
be slightly longer in deep snow
and on a gravel road when ABS
is activated. Therefore, always
keep in mind the road condition
and tire condition (type of tires
and worn condition), observe safe
(Continued)

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Driving and Operating 227
Conversions and
Add-Ons
Add-On Electrical
Equipment
Installing Electrical Equipment
{Warning
Inappropriate installation or
removal of audio, radio or other
electrical equipment can
adversely affect other electrical
equipment and cause a
breakdown or fire. Be sure to
have electrical equipment
installed or removed by your
dealer. You and others could be
seriously injured.
Do not install any unauthorized
radio set, or any radio set or
antenna that does not comply with
relevant standards. Noise from the
radio set could cause
electromagnetic interference with
the vehicle's electronic equipment and other systems, resulting in a
vehicle breakdown or in a
malfunction of electronic equipment.
Consult your dealer if you wish to
install radio equipment.
Power Take-Off (PTO)
If equipped, the PTO is a device
that is used to provide engine power
to special equipment directly from
the engine or through the
transmission. For details about the
PTO operation, refer to the separate
instruction manual provided by its
maker.
If the optional PTO function is used
for long periods of time, make sure
to regularly check the diesel
particulate filter (DPF) indicator.
Automatic DPF regeneration will not
take place while the PTO function is
active.
1. Engine Speed Control
Switch
2. Main Switch
{Warning
In PTO mode, Cruise Set/Resume
Switch can be used exactly the
same as PTO Engine Speed
Control Switch. Improper
operation of these switches may
cause personal injury or damage.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Vehicle Care 229
Vehicle Care
General Information
General Information . . . . . . . . . . 230
California Proposition65 Warning . . . . . . . . . . . . . . . . . 230
California Perchlorate Materials Requirements . . . . . 230
Accessories and Modifications . . . . . . . . . . . . . . . . 230
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 231
Cab Tilting . . . . . . . . . . . . . . . . . . . . 233
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 234
Engine Cover . . . . . . . . . . . . . . . . . 235
Engine Oil . . . . . . . . . . . . . . . . . . . . 235
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . 241
Engine Air Cleaner/Filter . . . . . . 243
Engine Coolant . . . . . . . . . . . . . . . 243
Engine Overheating . . . . . . . . . . 249
Power Steering Fluid . . . . . . . . . 252
Washer Fluid . . . . . . . . . . . . . . . . . 252
Brakes . . . . . . . . . . . . . . . . . . . . . . . 253
Brake Fluid . . . . . . . . . . . . . . . . . . . 258
Battery - North America . . . . . . 259 Fuel Filter . . . . . . . . . . . . . . . . . . . . 260
Rear Axle (Gear Oil Viscosity
Chart) . . . . . . . . . . . . . . . . . . . . . . . 261
Rear Axle (Oil Level Check) . . . . . . . . . . . . . . . . . . . . . . 262
Noise Control System . . . . . . . . 262
Automatic Transmission Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 264
Wiper Blade Replacement . . . . 265
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 267
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 267
Headlamps and Front Turn Signal . . . . . . . . . . . . . . . . . . . . . . . 270
Roofmarker Lamps . . . . . . . . . . . 274
Sidemarker Lamps (Including Turn Signal and Cornering
Lamps) . . . . . . . . . . . . . . . . . . . . . . 274
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 276
License Plate Lamp . . . . . . . . . . 276
Interior Lamps . . . . . . . . . . . . . . . . 277
Electrical System
Electrical System Overload . . . 277
Wheels and Tires
Wheels and Tires . . . . . . . . . . . . . 285
Tire Pressure . . . . . . . . . . . . . . . . . 297
Tire Rotation . . . . . . . . . . . . . . . . . 297
If a Tire Goes Flat . . . . . . . . . . . . 300
Jump Starting
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . 301
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . 305
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . 307
Interior Care . . . . . . . . . . . . . . . . . . 313

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Vehicle Care 241
or bodies of water. Instead, recycle
it by taking it to a used oil collection
facility which may be found in your
community.
Automatic Transmission
Fluid
{Warning
Overfilling of the automatic
transmission can cause the fluid
to be "PURGED" out of the
breather hose onto the hot engine
parts and can cause a fire.
You and others could be seriously
injured.
Both quality and quantity of fluid are
important factors that have a
significant influence on the
performance and durability of the
automatic transmission. Be sure to
use only the dealer recommended
fluid for replenishment, and observe
the specified fluid level. Too much or too little transmission
oil could damage your transmission.
Too much could cause your
transmission to overheat and fluid to
spill out from the breather hose. Be
sure to get an accurate reading if
you check your transmission fluid.
When cleaning around the dipstick
and guide tube, make sure that you
thoroughly wipe away all of the dirt
and dust etc. Failure to do so may
cause a fault in the transmission.
Do not let coolants (ethylene glycol
type), water based substances,
or other fluids etc., mix with the
fluid. Otherwise, degraded
performance and faulty operation of
the system will result.
Checking the Automatic
Transmission Oil level
This operation could be difficult and
you may choose to have this done
at your dealer.
If you choose to do it yourself, then
be sure to follow all the instructions
below or you could get a false
reading on the dipstick.Position of the Dipstick
For the single cab vehicle, the
dipstick is located to the left side of
the automatic transmission at the
rear of the engine. Tilt the cab up to
inspect it.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
242 Vehicle Care
For the crew cab vehicle, the
dipstick is located beneath the
rear-of-engine inspection panel.
After unlatching the A/T fluid
inspection cover, the dipstick will be
visible.
Inspection
Wait at least 30 minutes before
checking the transmission fluid if
you have been driving at high speed
for a long period of time, in city/
heavy traffic or while pulling a trailer.1. Start the engine, and drive the vehicle for approximately
10 minutes to warm up the
engine. During 10 minutes, the automatic transmission fluid
should reach a temperature of
approximately 70 - 80 °C (158 -
176 °F). During the winter
when temperatures are low,
adjust the amount of driving
time according to the actual
conditions.
2. Park the vehicle on level ground, and firmly apply the
parking brake.
3. With the engine idling, move the selector lever from the “P”
position to the “1”position
while pressing the brake pedal,
and then return the lever from
the “1”position to the “P”
position.
4. With the engine still idling, pull out the dipstick and wipe it with
a clean cloth.Transmission Dipstick
5. Reinsert the dipstick into position, pull out the dipstick
slowly, and check whether the
fluid level is within the “H”
marked range. Always check
the fluid level at least twice.
Consistently is important in
maintaining accuracy.
If inconsistent readings persist,
check the transmission
breather to ensure that it is
clean and free of debris.
. Dipstick C (COLD) —
Transmission fluid
temperature Approx. 20 -
30 °C (68 - 86 °F).