2020 CHEVROLET LOW CAB FORWARD maintenance schedule

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 263
particular part, component or
system of the vehicle manufactured
by General Motors. Defects in
design, assembly or in any part,
component or system of the vehicle
as manufactured by General
Motors, which, at the time it left
General Motors’s control, caused
noise emissions to exceed Federal
standards, are covered by this
warranty for the life of the vehicle.
The following information relates to
compliance with federal noise
emission standards for vehicles with
a Gross Vehicle Weight Rating
(GVWR) of more than 4 536 kg
(10,000 lb). The Maintenance
Schedule provides information on
maintaining the noise control system
to minimize degradation of the noise
emission control system during the
life of the vehicle. The noise control
system warranty is given in the
warranty manual.
These standards apply only to
vehicles sold in the United States.TAMPERING WITH NOISE
CONTROL SYSTEM
PROHIBITED
Federal law prohibits the following
acts or the causing thereof:1. The removal or rendering inoperative by any person,
other than for purposes of
maintenance, repair,
or replacement, of any device
or element of design
incorporated into any new
vehicle for the purpose of noise
control prior to its sale or
delivery to the ultimate
purchaser or while it is in
use; or
2. The use of the vehicle after such device or element of
design has been removed or
rendered inoperative by any
person.
Among those acts presumed to
constitute tampering are the acts
listed below. Insulation:
Removal of the noise shields or any
underhood insulation.
Engine:
Removal or rendering the engine
speed governor, if equipped,
inoperative so as to allow engine
speed to exceed manufacturer
specifications.
Fan and Drive:
.
Removal of the fan clutch,
if equipped, or rendering the
clutch inoperative.
. Removal of the fan shroud,
if equipped.
Air Intake:
. Removal of the air cleaner
silencer.
. Modification of the air cleaner.
Exhaust:
. Removal of the muffler and/or
resonator.
. Removal of the exhaust pipes
and exhaust pipe clamps.

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 287
occurs, reverse the position of the
tires to equalize wear and get better
tire life.
In addition, when trucks are driven
continuously on high-crown roads,
an increase in air pressure of
35 kPa (5 psi) in the outer tire of a
dual tire operation will prolong outer
tire life. Be sure not to exceed the
inflation pressure limits shown on
the“VIN, Weight Rating, and
Greenhouse Gas (GHG) Emissions
Plate.” SeeVehicle Identification
Number (VIN) 0343.
Wheel and Tire Balancing
Proper tire balancing provides the
best riding comfort and helps to
reduce tire tread wear.
Out-of-balance tires can cause
annoying vehicle vibration and
uneven tire wear, such as cupping
and flat spots. See your authorized
dealer for wheel balancing.
Front End Alignment
Proper front end alignment improves
tire tread mileage. Your vehicle's
front end suspension parts should
be inspected often and aligned when needed. (See the
Maintenance Schedule for more
information.) Improper alignment will
not cause the vehicle to vibrate;
however, improper toe-in alignment
will cause front tires to roll at an
angle that will result in faster tire
wear. Incorrect caster or camber
alignment will cause your front tires
to wear unevenly, and may cause
the vehicle to "pull" to the left or
right.
Tire Traction
A decrease in driving, cornering and
braking traction occurs when water,
snow, ice, gravel or other material is
on the road surface. Driving
practices and vehicle speed should
be adjusted to the road conditions.
When driving on wet or slushy
roads, it is possible for a wedge of
water to build up between the tire
and road surface. This is known as
hydroplaning, and may cause partial
or complete loss of traction, vehicle
control and stopping ability; this
condition is also more likely with
worn tires.
To reduce the chance of traction
loss, follow these tips:
.
Slow down during rainstorms or
when roads are slushy.
. Slow down if the road has
standing water or puddles.
. Replace tires when front tread
depth is 3.2 mm (4/32 in.) and
rear tread depth is 1.6 mm
(2/32 in.).
. Keep tires properly inflated.
Tire Replacement
Recommendations
{Warning
Do not mix different construction
types of tires on your vehicle such
as radial, bias and bias-belted
tires except in emergencies,
because vehicle handling could
be affected and may result in loss
of vehicle control, or personal
injury or death. (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
298 Vehicle Care
The difference in diameter of the
tires for a dual-tire wheel should be
within the limit specified in the table
below. If the limit is exceeded, the
tires wear more rapidly than they
should.
{Warning
If tires of different sizes, load
ranges, constructions, or tread
designs are used between the
front and rear axles, do not
exchange tires between the front
and rear axles; otherwise, the(Continued)
Warning (Continued)
tires may get loaded beyond their
limits. This will also affect vehicle
handling, brake performance, and
ride comfort. This is highly
dangerous because the tires and
disc wheels could break down
under an excessive load. You and
others could be seriously injured.
Permissible diameter difference
Radial tire Within 8 mm (0.31 in)
The tightening torque of the wheel
nuts may decrease after a tire
change due to their initial
settlement. Upon driving 50 to
100 km (31 to 62 mi) after a tire
change, retighten the wheel nuts to
the specified torques according to
the instructions in "Retightening
Wheel Nuts" following.
See Maintenance Schedule 0317.
Retightening Wheel Nuts
Check the wheel nuts to make sure
they are tightened to the specific
torque by using a torque wrench.
Use the following methods to check
loose wheel nuts. The tightening
torque of the wheel nuts may
decrease after a tire change or
rotation due to their initial
settlement. After driving 1 040 km
(650 mi) and after 10 400 km
(6,500 mi), be sure to retighten the
wheel nuts to the specified torque.
Repeat whenever a wheel, wheel
bolt, or wheel nut is removed.
Tightening torque
500 N·m (362 lb·ft)

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
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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.

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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