service schedule CHEVROLET LOW CAB FORWARD 2020 Owner's Manual

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 8/5/19
2 Introduction
Introduction
The names, logos, emblems,
slogans, vehicle model names, and
vehicle body designs appearing in
this manual including, but not limited
to, GM, the GM logo, CHEVROLET,
and the CHEVROLET Emblem are
trademarks and/or service marks of
General Motors LLC, its
subsidiaries, affiliates, or licensors.
This manual has been prepared to
acquaint you with the operation and
maintenance of your vehicle, and to
provide important safety information.
It includes a Maintenance Schedule
and is supplemented with a
Warranty and Owner Assistance
Information booklet. We urge you to
read these publications carefully.The following recommendations will
help ensure the most enjoyable,
safe, and trouble-free operation of
your vehicle. When it comes to
service, keep in mind that your
commercial truck dealer knows your
vehicle best and is interested in
your complete satisfaction. Your
dealer invites you to return for all of
your service needs both during and
after the warranty period.
Remember, if you have a concern
that has not been handled to your
satisfaction, follow the steps in the
separate Warranty and Owner
Assistance Information booklet. We
thank you for choosing our product,
and want to assure you of our
continuing interest in your motoring
pleasure and satisfaction.
Model Reference
The models covered in this
manual are:
Single Cab:.
4500HD
. 4500XD
. 5500HD
. 5500XD
Crew Cab:
. 4500HD
. 4500XD
. 5500HD
. 5500XD
Litho in U.S.A.
Part No. 84638328 B Second Printing©2019 General Motors LLC. All Rights Reserved.

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
Instruments and Controls 77
Exhaust System Warning Light
EXH. SYSTEM
This light comes on when the SCR
system detects a malfunction or
incorrect DEF. SCR system will turn
on other indicator lights and reduce
engine power in progressive stages
to encourage you to have the
malfunction corrected. Continuing to
drive for too long after this light
turns on will eventually result in a
severe vehicle speed limitation.
If this light turns on, promptly have
the vehicle inspected and serviced
at your dealer. SeeDiesel Exhaust
Fluid 0180.
Refill Diesel Exhaust Fluid
(DEF) Warning Light
REFILL DEF
This message displays and a
warning light appears when the DEF
tank is almost empty. Add DEF as
soon as possible.
Engine power will be reduced and
vehicle speed will be limited when
this light is activated. Failure to
promptly refill the DEF tank will result in a severe vehicle speed
limitation. See
Diesel Exhaust Fluid
0 180.
When DIC ERROR is Displayed
ERROR
If the system has not yet been able
to access maintenance data,
ERROR is shown on the DIC.
If ERROR does not change
automatically to a distance or other
maintenance indication, have your
vehicle serviced at your dealer.
Maintenance Data Indicator
Lights
Maintenance data indicator lights
appear on the DIC when each
maintenance item is selected or
when the next change or service
interval of the item is near or has
been reached.
The distance or time shown is the
remaining or excess of them to /
from the change or service timing.
The positive distance or time shows
the remaining of that and the
negative distance or time shows the excess of that. For the items listed
below, the displayed color will
change from green to amber when
remaining distance is below
1 600 km (1,000 mi) and the screen
is selected.
These screens are also displayed
when the engine control switch
turns to the ON position after above
notification timing. The message
remains on the display until the DIC
selector is pressed once or the
vehicle is started.
The maintenance data function
indicates the distance remaining
before the next scheduled
maintenance. Scheduled
maintenance time is approaching
when the display turns from green
to amber. Have the vehicle checked
and serviced at your dealer as soon
as possible.
The vehicle needs to be maintained
more often if it is driven in severe
conditions.

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 243
.Dipstick H (HOT) —
Transmission fluid
temperature Approx. 70 -
80 °C (158 - 176 °F).
. The “C (COLD)” range on
the dipstick is a guide used
by your dealer for
specialized equipment used
to replace or service the
automatic transmission
fluid. When performing your
own inspections, always
use the “H (HOT)” range
after warming up the
vehicle.
The fluid must be hot to
ensure an accurate check.
The fluid level rises as
temperature increases.
6. If the fluid level is too low, add the specified fluid through the
dipstick guide tube. Also, check
whether there are no fluid
leaks.
7. Insert the dipstick securely into position.{Warning
Be extremely careful not to burn
yourself when checking the oil
level if the engine temperature is
high. Protect yourself with
gloves etc.
You and others could be seriously
injured.
Discarded parts, oil, grease and
fluids could have an adverse effect
on the environment. It is difficult to
dispose of these, so have your
dealer handle all checks and
replacements.
Engine Air Cleaner/Filter
Air Cleaner
Using a clogged air cleaner element
not only reduces engine output but
also causes increased fuel
consumption and an increased DPF
regeneration frequency. Be sure to use a genuine air cleaner
element. If a different air cleaner
element is used, it may cause the
sensor to output a wrong signal.
See
Maintenance Schedule 0317.
Air Cleaner Indicator Light
When the air cleaner indicator light
comes on, check the air cleaner
element. If the air cleaner element is
clogged, replace the air cleaner
element.
See Vehicle Messages 074.
See Maintenance Schedule 0317.
Engine Coolant
Protection of Engine Against
Overcooling
Overcooling of the engine not only
accelerates wear of the vital engine
parts but also hurts fuel economy.

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
Service and Maintenance 317
Service and
Maintenance
Maintenance Schedule
Maintenance Schedule . . . . . . . 317
Owner Checks and Services
Owner Checks andServices . . . . . . . . . . . . . . . . . . . . 330
Additional Maintenance
and Care
Additional Maintenanceand Care . . . . . . . . . . . . . . . . . . . . 336
Recommended Fluids,
Lubricants, and Parts
Recommended Fluids andLubricants . . . . . . . . . . . . . . . . . . . 339
Maintenance Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . 341
Maintenance
Schedule
Caution
Damage caused by improper
maintenance can lead to costly
repairs and may not be covered
by the vehicle warranty.
Maintenance intervals, checks,
inspections, recommended fluids,
and lubricants are important to
keep the vehicle in good working
condition.
Do not have chemical flushes that
are not approved by GM
performed on the vehicle. The
use of flushes, solvents, cleaners,
or lubricants that are not
approved by GM could damage
the vehicle, requiring expensive
repairs that are not covered by
the vehicle warranty.
Make sure the vehicle is inspected
at regular intervals. Inspections and
maintenance enable you to use the vehicle with peace of mind. They
also extend the vehicle's
service life.
For safe and economical driving, we
recommend that you have your
vehicle inspected and serviced
regularly according to the schedule
indicated in this chapter.
To drive your vehicle safely and at
minimum cost, it is essential to have
your vehicle regularly inspected and
serviced at your dealer as per the
specified maintenance schedule.
Contact your dealer for inspection
that requires disassembly and/or
special equipment.
The Maintenance Schedule in this
manual and a Warranty Information
Booklet are supplied with your
vehicle. Read all publications for a
full understanding of your vehicle's
maintenance needs.
The quality of maintenance your
new vehicle receives is as important
as the regularity with which it is
serviced. Authorized dealers provide
nationwide quality in customer
service. The program includes the

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
318 Service and Maintenance
training of dealer technicians
throughout the country and is
supported with a continuous
follow-up of publications and other
service information. The use of
genuine parts and accessories,
which have the same high quality
standards as original equipment
parts, and the use of factory
approved tools developed and
tested for use by the authorized
dealer also contribute to the high
quality of service.
If you have any questions on how to
keep your truck or chassis in good
condition, see your authorized
dealer, the place many truck owners
choose to have their maintenance
work done. Your authorized dealer
can be relied upon to use proper
parts and practices.
Some of these services can be
complex, so unless you are
technically qualified and have the
necessary equipment, you should
let your authorized dealer's service
department or another qualified
service center do these jobs.The schedule includes general
maintenance which you or a
qualified technician should perform
periodically.
Explanation of Vehicle
Maintenance and Log
The following is a brief explanation
of normal vehicle use.
NORMAL VEHICLE USE—The
maintenance instructions contained
in this section are based on the
assumption that your vehicle will be
used as designed:
.
To carry passengers and cargo
with the limitations indicated on
the vehicle VIN and GVW plate.
. On reasonable road surfaces
within legal operating limits.
. On a daily basis, as a general
rule, for at least several miles/
kilometers.
Unusual operating conditions, such
as driving in dusty areas (sweeper,
agricultural or off-road vehicles),
extended idling (refrigeration vehicles), or vehicles operated for
frequent short trips, will require
more frequent vehicle maintenance.
The log groups items according to
mile/kilometer service intervals. Use
the item codes (letter and number)
to find the description of the
maintenance and the time intervals.
Follow whichever interval comes
first, time or miles/kilometers.
After the maintenance services are
performed, insert the month, day
and mileage/ kilometers in the area
provided next to the serviced item.
The services shown up to
176 000 km (110,000 miles) are to
be repeated after the initial
176 000 km (110,000 miles) at the
same intervals.
Severe Driving Conditions
A vehicle operated under severe
conditions (see list below) requires
more frequent maintenance.
.
Frequent short trips of less than
6 kilometers (4 miles) in
moderate temperatures

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
Service and Maintenance 319
.Frequent short trips of less than
16 kilometers (10 miles) in sub-
freezing temperatures
. Frequent and extended low-
speed engine operation (door-
to- door deliveries, stop- and- go
traffic, etc.)
. Driving on unpaved roads with
heavy dust
. Towing a trailer
Power Take Off (PTO) and
Extended Idle Use
When the vehicle is used with the
PTO equipment or used in a way
that requires extended idle time,
one hour of use shall be deemed
the same as 33 miles. See Driver
Information Center (DIC) 070 for
hourmeter.
Preventive Maintenance
As any mechanical device operates,
a certain amount of wear occurs.
The amount of wear depends on
certain variables –type and method
of operation and the schedule of
maintenance. These variables may be emphasized as critical to
malfunction but each is dependent
upon the other. For example, if a
vehicle is repeatedly overloaded,
driven at excessive speed or
improperly shifted, no schedule of
maintenance can prevent
malfunction. Also, if a preventive
maintenance schedule is not
followed, or is improperly carried
out, no amount of correct vehicle
operation will prevent malfunction.
If vehicle application, operation and
preventive maintenance schedules
and procedures are followed and
properly carried out, the life of the
vehicle will be greatly extended.
For example, regular attention to the
engine oil is essential. The oil level
must be periodically checked and oil
added whenever needed. Also, the
oil should be changed at the
intervals specified with the proper
quality and viscosity of oil. If your
engine should run excessively low
on oil or if the oil has lost its
lubricating qualities because of old
age, serious engine damage could
occur.
Maintenance Schedule Table
Letters Used to Indicate
Maintenance Service Types
I :
Inspect then clean, repair or
replace as necessary
A : Adjust
R : Replace
T : Tighten to the specified torque
L : Lubricate
C : Clean

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
Service and Maintenance 325
maintenance intervals and may
cause a problem with engine
durability.
(3)Refer to "Air Cleaner Indicator
Light" under Engine Air Cleaner/
Filter 0243.
(4) Initial check at 1 040 km
(650 miles) is required.
(5) Be sure to discard used grease
seal, and always use new grease
seal for installation.
Explanation of Complete
Vehicle Maintenance Schedule
The following is a brief explanation
of each of the services listed in the
preceding Complete Vehicle
Maintenance Schedule.
1. Engine Noise : These
components have an effect on the
control of noise emissions. Service Interval Maintenance procedure
Engine
Every 16 000 km (10,000 miles) Inspect sound absorption materials for
tears, broken out sections or
attachment. Repair or replace as
necessary.
Cooling System
Every 16 000 km (10,000 miles) Inspect fan, shroud and radiator for
attachment, tears or cleanliness.
Replace as necessary.
Air intake system
Every 24 000 km (1,500 miles) Inspect all ducts, hoses and intake
silencers for leaks or chafing. Repair or
replace as necessary.
Exhaust system
Every 16 000 km (10,000 miles) Inspect silencer, pipes, gaskets, clamps
and mounting for exhaust gas leaks or
looseness. Repair or replace as
necessary.
Cab
Every 16 000 km (10,000 miles) Inspect sound absorption materials for
tears, broken out sections or
attachment. Repair or replace as
necessary.
2. Valve Lash : Incorrect valve
clearance will result in increased
engine noise and lower engine
output, thereby adversely affecting
engine performance. Retorque rocker shaft bracket nuts before
checking and adjusting valve
clearance.
Check and adjust valve clearance
every 80 000 km (50,000 miles) or
12 months whichever occurs first.

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
326 Service and Maintenance
3. Engine Oil and Oil Filter :
Change at interval noted below
depending upon driving conditions.
•Normal Service —Change every
16 000 km (10,000 miles) or
12 months whichever occurs first.
• Severe Service —Change every
8 000 km (5,000 miles) or 3 months
if you often drive under one or more
of these conditions: (a) driving in
dusty areas, (b) frequent idling or
idling for long periods, (c) driving
6 km (4 miles) or less in freezing
weather, or other short trips in cold
weather, where the engine does not
thoroughly warm up.
Change oil and filter as soon as you
can after driving in a dust storm.
When recommended oil is used, it
conforms to this maintenance
schedule. (Recommended oil: CK-4
(API designations))
4. Fuel Filter : Replace the fuel
filter every 24 000 km (15,000 miles)
or more frequently if clogged or
replace when the fuel filter indicator
light comes on (if equipped). 5. Pre-Fuel Filter/Water
separator :
Replace the fuel filter
every 24 000 km (15,000 miles) or
more frequently if clogged or
replace when the fuel filter indicator
light comes on (if equipped).
6. Air Cleaner Filter : The level of
dirt in the air cleaner element can
be checked against the indicator.
Replace the air cleaner filter when
the Driver Information Center (DIC)
shows "CHECK AIR FILTER".
7. Damage to Air Intake Ducts and
Hoses : Check for damage of air
intake ducts and hoses and that
those are correctly installed every
24 000 km (15,000 miles) or
12 months. Replace or adjust those
if necessary.
8. Drive Belts : Check belt driving
the fan, alternator or A/C
compressor every 16 000 km
(10,000 miles). Look for cracks,
fraying, wear, and proper tension.
9. Engine Bolt Torques : Loosened
bolts result in lower engine output.
Check and adjust manifold mounting, and injectors to correct
torque every 80 000 km
(50,000 miles).
10. Rotate Tires :
To equalize wear,
rotate tires and adjust tire pressures
every 10 400 km (6,500 miles). See
Tire Rotation 0297.
11. Engine Cooling System : At
12 months or 16 000 km
(10,000 miles) intervals, wash
radiator cap and filler neck with
clean water, pressure test system
and radiator cap for proper pressure
holding capacity, tighten hose
clamps and inspect condition of all
cooling and heater hoses. Replace
hoses if cracked, swollen or
otherwise deteriorated. Have the
hoses replaced by your authorized
dealer.
12. Engine Coolant : Inspect the
engine coolant every 12 months.
Replace the engine coolant every
24 months, drain the engine coolant
by opening the drain plug at the
bottom of the radiator core, flush
and refill the engine cooling system
with a new engine coolant. Refer to
"Preparing Engine Coolant" in

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
Service and Maintenance 331
Recommended Daily
(Pre-operation) Inspections
These checks are in addition to, not
instead of, any legally required daily
inspections. See related topics
under "Maintenance Schedule",
especially if problems are found.
For safe and comfortable driving,
keep record of the distances driven
and the condition of the vehicle
during operation. Perform
inspections at appropriate intervals,
and perform maintenance in
accordance with the findings of the
inspections. If an inspection reveals
an abnormality or there was an
abnormality the previous time the
vehicle was driven, have the vehicle
repaired by the nearest dealer
before it is driven again.1. Components that showed abnormalities during the
previous operation
.Check components that
showed abnormalities
during the previous
operation 2. Checks performed at the
engine
.Fan belt looseness and
damage
. Engine oil level
. Engine coolant level
. Power steering fluid level
3. Checks performed from the driver's seat
.Brake fluid level
. Brake pedal free play
. Operation of meters,
gauges and warning/
indicator lights
. Engine startability,
abnormal noise and color of
exhaust gases
. Parking brake lever stroke
. Windshield washer fluid
spray condition and
windshield wiper
effectiveness
. Windshield washer fluid
level .
Steering wheel position and
free play
. Operation of horn and turn
signal lights
. Door lock operation
4. Checks performed during a walk around the vehicle
.Illumination, flashing,
contamination, damage and
obstruction of lights
. Contamination, damage ad
obstruction of windows,
mirrors and reflectors
. Leaf spring damage
. Oil, engine coolant, fuel,
brake fluid and power
steering fluid leaks
. Water separator
5. Checking wheels and tires .Air pressure
. Cracks and other damage
. Abnormal wear
. Tread depth

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
Service and Maintenance 333
Front
1. Roofmarker Lamp(Identification/
Clearance Lamp)
2. Front Turn Signal Lamp
3. Side Turn Signal Lamp/ Sidemarker Lamp
4. Cornering Lamp
5. Side Reflector
6. Headlamp/Parking Lamp
Rear
1. Rear Turn Signal Lamp
2. Back-up Lamp
3. License Plate Lamp
4. Taillamp/Stoplamp
Lubrication
One of the most important items of
good vehicle care is the lubrication
of all necessary points with the
Right Lubricant, at the Right Time
and in the Right Way. It is the
owner's responsibility to maintain
proper lubrication practices as
recommended in the following
pages. Greasing Chassis Components
The type (characteristics) of the
grease specified for use with a
chassis component differs from that
of the grease specified for use with
another component. Be sure to use
only the specified grease for each
component and perform greasing
according to the Maintenance
Schedule.
King pins (left and right)