2019 Chevrolet Silverado 3500HD Fluid Type Specs

Quick reference

Fluid	Type/Spec	Capacity (approx.)
Engine Oil (6.0L LY6)	SAE 5W-30, dexos1 Gen2 (or newer dexos1 spec)	6.0 quarts
Engine Oil (6.6L L5P Duramax)	SAE 15W-40 or 5W-40, dexos2 (or newer dexos D spec)	10.0 quarts
Engine Coolant	DEX-COOL Extended Life Antifreeze/Coolant (GM Spec 6277M)	16.5 quarts (6.0L); 22.0 quarts (6.6L Duramax)
Transmission Fluid (6L90)	DEXRON VI Automatic Transmission Fluid	11.0 quarts (initial fill)
Transmission Fluid (Allison 1000)	DEXRON VI Automatic Transmission Fluid	12.0 - 13.0 quarts (initial fill)
Transfer Case (MP 1625/1626)	AutoTrak II Transfer Case Fluid (GM Spec 9985219)	1.5 - 2.0 quarts
Front Differential (2WD/4WD)	SAE 75W-90 Synthetic Axle Lubricant (GM Spec 9986115)	1.8 - 2.0 quarts
Rear Differential (SRW)	SAE 75W-90 Synthetic Axle Lubricant (GM Spec 9986115)	2.6 - 3.0 quarts
Rear Differential (DRW)	SAE 75W-90 Synthetic Axle Lubricant (GM Spec 9986115)	4.2 - 4.5 quarts
Brake Fluid	DOT 3 or DOT 4 Hydraulic Brake Fluid	As needed
Power Steering Fluid	DEXRON VI Automatic Transmission Fluid	As needed
Washer Fluid	GM Optikleen Washer Solvent or equivalent	1 gallon
Diesel Exhaust Fluid (DEF)	ISO 22241 (AdBlue Certified)	7.0 gallons

Engine Oil

The 2019 Chevrolet Silverado 3500HD was available with two primary engine options: the 6.0L LY6 Vortec V8 gasoline engine and the 6.6L L5P Duramax turbo-diesel V8 engine. It is crucial to use the correct engine oil specification for your specific engine.

For the 6.0L LY6 Vortec V8 gasoline engine, the factory fill is SAE 5W-30 engine oil meeting the GM dexos1 Gen2 specification (or the latest dexos1 generation available, such as Gen3). This specification ensures proper lubrication, protection against low-speed pre-ignition (LSPI), and fuel economy. The oil capacity is approximately 6.0 quarts with a filter change. Oil change intervals are typically indicated by the vehicle's Oil Life Monitoring (OLM) system, but generally range from 7,500 to 10,000 miles or one year, whichever comes first. Always check your owner's manual for the most accurate information.

For the 6.6L L5P Duramax turbo-diesel engine, the factory fill can be either SAE 15W-40 or SAE 5W-40 engine oil. Both must meet the GM dexos2 specification. Newer diesel engines may also specify the dexos D specification, which supersedes dexos2 for some applications and offers enhanced protection. Always consult your owner's manual for the precise specification, particularly if using a newer oil. The oil capacity for the Duramax is substantial, at approximately 10.0 quarts with a filter change. Duramax engine oil change intervals are also dictated by the OLM system but can be as frequent as every 7,500 miles under severe conditions or extended up to 15,000 miles for light-duty use. Severe duty includes frequent towing/hauling, excessive idling, or dusty conditions.

Common Pitfalls: Using non-dexos approved oil in the gasoline engine can lead to premature wear and potentially void your warranty. For the diesel, using passenger car engine oil or oil not certified to dexos2/dexos D can cause damage to emission system components (like the Diesel Particulate Filter – DPF) and the engine itself.

Engine Coolant

The 2019 Silverado 3500HD requires GM DEX-COOL Extended Life Antifreeze/Coolant. This is an Organic Acid Technology (OAT) coolant, typically orange or red in color, and meets GM Spec 6277M. This coolant is designed for extended service intervals, generally up to 5 years or 150,000 miles, whichever comes first. The system capacity for the 6.0L gasoline engine is about 16.5 quarts, while the 6.6L Duramax engine holds approximately 22.0 quarts.

Common Pitfalls: Mixing DEX-COOL with conventional green (inorganic acid technology - IAT) or hybrid (HOAT, OAT/HOAT blends) coolants can lead to chemical reactions that cause gel formation, sediment, and corrosion, severely damaging the cooling system. Always flush the system thoroughly if switching coolant types (though not recommended), and only top off with DEX-COOL or an equivalent OAT coolant meeting GM 6277M. Ensure the coolant is silicate-free and phosphate-free to prevent premature water pump seal wear and deposit formation.

Transmission Fluid

The 2019 Silverado 3500HD could be equipped with either the 6L90 6-speed automatic transmission (typically with the 6.0L gasoline engine) or the Allison 1000 6-speed automatic transmission (with the 6.6L Duramax diesel engine). Both transmissions specify DEXRON VI Automatic Transmission Fluid.

DEXRON VI is a fully synthetic fluid engineered for improved durability, wear protection, and consistent shift performance across a wide range of temperatures. For the 6L90, the initial fill capacity is around 11.0 quarts. For the Allison 1000, initial fill capacities can range from 12.0 to 13.0 quarts depending on the cooler and lines. A complete flush will require more. Transmission fluid change intervals vary significantly based on usage. Under normal conditions, intervals can be as long as 100,000 miles, but for heavy towing, hauling, or frequent off-road use, it's advisable to shorten this to 50,000 miles or even less. Always refer to your owner's manual and consider a fluid and filter change for optimum transmission health.

Common Pitfalls: Never use "universal" or non-DEXRON VI compliant ATF. Using the wrong fluid can lead to shudder, inaccurate shifts, excessive wear, and complete transmission failure. DEXRON VI is backward compatible with earlier DEXRON specifications (DEXRON, DEXRON-II, DEXRON-III) but offers superior performance.

Transfer Case Fluid

For 4WD models, the 2019 Silverado 3500HD typically uses an MP 1625 or MP 1626 transfer case. These transfer cases require AutoTrak II Transfer Case Fluid (GM Spec 9985219). This is a specialized blue-colored fluid designed for the specific clutch materials and electronic controls within GM's active transfer cases. The capacity is generally between 1.5 to 2.0 quarts. Transfer case fluid should typically be changed every 50,000 to 100,000 miles, or more frequently under severe conditions like heavy towing or off-road driving. Always check your owner's manual.

Common Pitfalls: Do not substitute AutoTrak II with any other fluid, including common ATF or gear oils. The unique friction modifiers and viscosity characteristics of AutoTrak II are critical for proper transfer case operation and clutch pack longevity. Using incorrect fluid will lead to premature wear and potential binding or engagement issues.

Differential Gear Oil

Both the front and rear differentials in the 2019 Silverado 3500HD require SAE 75W-90 Synthetic Axle Lubricant meeting GM Spec 9986115. This is a full synthetic gear oil designed for excellent protection across a broad temperature range and under heavy loads. Capacities generally range from 1.8 to 2.0 quarts for the front differential. Rear differential capacities vary: approximately 2.6 to 3.0 quarts for Single Rear Wheel (SRW) models and 4.2 to 4.5 quarts for Dual Rear Wheel (DRW) models.

If your vehicle is equipped with a limited-slip differential (LSD), ensure that the chosen 75W-90 gear oil either already contains the necessary friction modifiers for LSD applications or that an appropriate LSD additive is blended in according to the oil manufacturer's instructions. Some GM rear differentials were available with Eaton Gov-Lok automatic locking differentials, which typically do not require additional friction modifier.

Differential fluid change intervals can range from 50,000 to 100,000 miles, or more often if the vehicle is frequently used for towing/hauling heavy loads or in off-road conditions where the differentials are subjected to extreme stress and heat.

Common Pitfalls: Using conventional (non-synthetic) gear oil can lead to accelerated wear and reduced protection, especially under heavy loads and high temperatures. Incorrect viscosity can also impact component life. Always verify if an LSD additive is needed based on your differential type and chosen lubricant.

Brake Fluid

The 2019 Silverado 3500HD uses standard hydraulic brake fluid. General Motors specifies either DOT 3 or DOT 4 Hydraulic Brake Fluid. DOT 4 fluid has a higher wet and dry boiling point than DOT 3, offering better performance under prolonged braking or heavy use, and is typically compatible for systems designed for DOT 3. Always check your owner's manual for the specific recommendation, but upgrading from DOT 3 to DOT 4 is generally acceptable and beneficial. Never use DOT 5 silicone-based fluid, as it is not compatible with conventional brake systems.

Brake fluid should ideally be flushed and replaced every 2 to 3 years regardless of mileage, as it is hygroscopic, meaning it absorbs moisture from the air. This moisture lowers the fluid's boiling point, leading to a spongy pedal and reduced braking efficiency, especially under hard braking, and can also cause internal corrosion in brake components.

Common Pitfalls: Mixing DOT 3, DOT 4, or DOT 5.1 (glycol-based) with DOT 5 (silicone-based) will cause severe system damage. Using old or contaminated fluid severely compromises braking performance and safety.

Power Steering Fluid

For the 2019 Chevrolet Silverado 3500HD, the power steering system typically uses DEXRON VI Automatic Transmission Fluid. This is the same fluid specified for the automatic transmissions. While some older GM vehicles used a dedicated power steering fluid, newer models often consolidate to DEXRON VI due to its robust properties and wide temperature range performance. Always verify with your owner's manual.

Power steering fluid usually does not have a strict replacement interval but should be inspected periodically for contamination or low levels. If the fluid appears dark, has a burnt smell, or if there are signs of power steering pump noise, a fluid flush may be beneficial.

Common Pitfalls: Using generic power steering fluid or a non-DEXRON VI fluid can lead to premature wear of power steering pump components and seals, resulting in noise or failure.

Washer Fluid

Any commercially available windshield washer fluid is suitable for the 2019 Silverado 3500HD. General Motors often recommends their own GM Optikleen Washer Solvent or an equivalent. It is advisable to use a washer fluid designed for all-season use, offering freeze protection in cold climates and effective Bug/Tar removal in warmer months, for optimal visibility. Capacity is approximately 1 gallon.

Diesel Exhaust Fluid (DEF)

For 6.6L L5P Duramax diesel engines, Diesel Exhaust Fluid (DEF) is required for the Selective Catalytic Reduction (SCR) system. DEF is a non-toxic solution of 32.5% high-purity urea and 67.5% de-ionized water. It must meet the ISO 22241 standard and be AdBlue certified. The DEF tank capacity is approximately 7.0 gallons.

DEF consumption is usually around 2% of fuel consumption, meaning you'll typically refill the DEF tank less frequently than your fuel tank. The vehicle's instrument cluster will provide warnings when DEF levels are low. Do not ignore these warnings, as the engine's power will be significantly reduced, and eventually, the vehicle will not restart if the DEF tank is empty.

Common Pitfalls: Never use anything other than ISO 22241 certified DEF. Do not put DEF in the diesel fuel tank, and do not put diesel fuel in the DEF tank. Both will cause catastrophic damage. Store DEF in a cool, dry place, as it has a shelf life of about 1-2 years and can freeze at approximately 12°F (-11°C) – although the vehicle has a DEF heater, frozen DEF must thaw before the system can operate. Only use product from sealed containers to prevent contamination.

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