GMC Chevrolet Silverado 2500HD 2021 Owner's Manual page 400

I3500 Series Chassis Cab
I3500 Series Chassis Cab
Transfer Case Fluid
Hydraulic Power Steering Fluid
Wheel Nut Torque
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.
6.6L V8 (L8T)
Spark plug gaps are preset by the manufacturer. Re-gapping the spark plug is not recommended and can damage the spark plug.
Application
Front Tank
Rear Tank
Engine Specifications
Engine
Capacities
Metric
89.0 L
151.4 L
2.3 L
2.0 L
190
VIN Code
7 0.95 1.10 mm (0.037 0.043 in)
Technical Data 399
English
23.5 gal
40.0 gal
2.4 qt
2.1 qt
140 lb ft
Spark Plug Gap