Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
390 Service and Maintenance
Footnotes—Maintenance Schedule
Additional Required Services - Severe
(1) Or every four years, whichever comes
first. If driving in dusty conditions, inspect
the filter at each oil change or more often
as needed. See Engine Air Cleaner/Filter
0 309.
(2) Or every two years, whichever comes
first. More frequent replacement may be
needed if the vehicle is driven in areas with
heavy traffic, poor air quality, areas with
high dust levels or are sensitive to
environmental allergens. Filter replacement
may also be needed if you notice reduced
airflow, windows fogging up, or odors. Your
local GM Service location can help you
determine when it is the right time to
replace your filter.
(3) Visually check all fuel and vapor lines
and hoses for proper attachment,
connection, routing, and condition.
(4) Do not directly power wash the transfer
case and/or front/rear axle output seals.
High pressure water can overcome the seals
and contaminate the fluid. Contaminated
fluid will decrease the life of the transfer
case and/or drive axles and should be
replaced. (5)
Or every five years, whichever comes
first. See Cooling System 0310.
(6) Or every 10 years, whichever comes first.
Inspect for fraying, excessive cracking,
or damage; replace, if needed.
(7) Replace brake fluid every five years. See
Brake Fluid 0317.
(8) Or every 12 months, whichever comes
first. See Wiper Blade Replacement 0322.
(9) Or every 10 years, whichever comes first.
See Gas Strut(s) 0323.
(10) Replace air conditioning desiccant every
seven years.
Special Application Services
.Vehicles with Dual Wheels: Check dual
wheel nut torque at 160, 1 600, and
10 000 km (100, 1,000, and 6,000 mi) of
driving. Repeat this service whenever a
tire/wheel is serviced or removed.
.Severe Commercial Use Vehicles Only:
Lubricate chassis components every oil
change.
.Have underbody flushing service
performed. See “Underbody Maintenance”
in Exterior Care 0373.
Additional Maintenance
and Care
Your vehicle is an important investment and
caring for it properly may help to avoid
future costly repairs. To maintain vehicle
performance, additional maintenance
services may be required.
It is recommended that your dealer perform
these services —their trained dealer
technicians know your vehicle best. Your
dealer can also perform a thorough
assessment with a multi-point inspection to
recommend when your vehicle may need
attention.
The following list is intended to explain the
services and conditions to look for that may
indicate services are required.
Battery
The 12-volt battery supplies power to start
the engine and operate any additional
electrical accessories.
.To avoid break-down or failure to start
the vehicle, maintain a battery with full
cranking power.
Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Technical Data 399
ApplicationCapacities
Metric English
I3500 Series Chassis Cab –Front Tank 89.0 L
23.5 gal
I3500 Series Chassis Cab –Rear Tank 151.4 L
40.0 gal
Transfer Case Fluid 2.3 L2.4 qt
Hydraulic Power Steering Fluid 2.0 L2.1 qt
Wheel Nut Torque 190Y 140 lb ft
All capacities are approximate. When adding, be sure to fill to the approximate level, as recommended in this manual. Recheck fluid level
after filling.
*Engine cooling system capacity values are based on the entire cooling system and its components.
Engine Specifications
Engine VIN CodeSpark Plug Gap
6.6L V8 (L8T) 70.95–1.10 mm (0.037–0.043 in)
Spark plug gaps are preset by the manufacturer. Re-gapping the spark plug is not recommended and can damage the spark plug.
