2019 GMC Sierra 1500 Fluid Type Specifications Guide

Quick Reference

Fluid	Type/Spec	Capacity
Engine Oil	dexos1 Gen2 (5.3L/6.2L Gas: 0W-20; 4.3L Gas: 5W-30), dexosD (3.0L Duramax Diesel: 0W-20)	5.3L Gas: 8.0 quarts; 6.2L Gas: 8.5 quarts; 4.3L Gas: 6.0 quarts; 3.0L Duramax Diesel: 7.0 quarts
Engine Coolant	DEX-COOL Antifreeze (GM Spec 6277M)	~16.0–17.0 quarts (verify in owner's manual)
Transmission Fluid	DEXRON VI Automatic Transmission Fluid	10-speed: ~12.0 quarts; 8-speed: ~12.0 quarts; 6-speed: ~11.0 quarts (verify in owner's manual)
Transfer Case	DEXRON VI Automatic Transmission Fluid (Autotrac II compatible in some models)	~1.5 - 2.0 quarts (verify in owner's manual)
Front Differential	SAE 75W-90 Synthetic Axle Lubricant (GM Spec 9986115)	~1.7 - 1.9 quarts (verify in owner's manual)
Rear Differential	SAE 75W-90 Synthetic Axle Lubricant (GM Spec 9986115) or SAE 75W-140 Synthetic Axle Lubricant for Heavy Duty Trailering (GM Spec 9986115, verify for locking differential)	~2.5 - 2.8 quarts (verify in owner's manual)
Brake Fluid	DOT 3 or DOT 4 Motor Vehicle Brake Fluid	As needed
Power Steering	Electronically Assisted (No Fluid)	N/A
Washer Fluid	Pre-mixed Windshield Washer Solvent	~1 Gallon
DEF	API CK-4 / ISO 22241 (for 3.0L Duramax Diesel)	5.0 gallons

Engine Oil

For your 2019 GMC Sierra 1500, the factory-spec engine oil varies depending on the engine.

• 5.3L and 6.2L Gas Engines: Require SAE 0W-20 full synthetic engine oil meeting the dexos1 Gen2 specification.
• 4.3L Gas Engine: Requires SAE 5W-30 full synthetic engine oil meeting the dexos1 Gen2 specification.
• 3.0L Duramax Diesel Engine: Requires SAE 0W-20 full synthetic engine oil meeting the dexosD specification. This is a specific diesel engine oil standard and is not interchangeable with dexos1 Gen2.

Capacity:

• 5.3L Gas: Approximately 8.0 quarts
• 6.2L Gas: Approximately 8.5 quarts
• 4.3L Gas: Approximately 6.0 quarts
• 3.0L Duramax Diesel: Approximately 7.0 quarts

Intervals and Pitfalls: Engine oil and filter should be changed according to the maintenance schedule in your owner's manual or as indicated by the vehicle's Oil Life Monitoring System. Using an oil that does not meet the specified dexos standard can lead to premature engine wear and may void your warranty. Always ensure you are using the correct dexos specification for your engine type.

Engine Coolant

Your 2019 GMC Sierra 1500 uses DEX-COOL Extended Life Antifreeze/Engine Coolant, which is an Organic Acid Technology (OAT) coolant. This is identifiable by its typically orange or red/pink color. The GM specification for DEX-COOL is GM Spec 6277M.

Capacity: The cooling system capacity is approximately 16.0–17.0 quarts. Always verify the exact capacity in your owner's manual.

Intervals and Pitfalls: DEX-COOL is designed for long service intervals, often around 5 years or 150,000 miles, whichever comes first. However, always refer to your owner's manual for the precise maintenance schedule. A critical pitfall is mixing DEX-COOL with other types of coolants, especially older Inorganic Acid Technology (IAT) or Hybrid Organic Acid Technology (HOAT) coolants. Mixing coolants can lead to chemical incompatibilities, gel formation, corrosion, and severe damage to the cooling system and engine. When topping off or refilling, always use DEX-COOL or a coolant specifically labeled as compatible with GM Spec 6277M.

Transmission Fluid

The 2019 GMC Sierra 1500 uses DEXRON VI Automatic Transmission Fluid for its automatic transmissions (6-speed, 8-speed, and 10-speed variants). DEXRON VI is a full synthetic fluid developed for improved performance and extended drain intervals.

Capacity:

• 10-speed automatic transmission: Approximately 12.0 quarts
• 8-speed automatic transmission: Approximately 12.0 quarts
• 6-speed automatic transmission: Approximately 11.0 quarts

Exact capacities can vary based on transmission model and fluid retention during a drain and fill. Always verify with your owner's manual.

Intervals and Pitfalls: Transmission fluid change intervals can vary significantly based on driving conditions (e.g., heavy towing, frequent stop-and-go driving). Consult your owner's manual for the recommended service schedule. A major pitfall is using any transmission fluid that is not DEXRON VI. "Universal" or multi-vehicle ATFs often do not meet the specific requirements of DEXRON VI, which can lead to poor shift quality, reduced transmission life, and potential damage.

Transfer Case

For 4WD and AWD models of the 2019 GMC Sierra 1500, the transfer case typically uses DEXRON VI Automatic Transmission Fluid. Some specific transfer case models might require a fluid compatible with Autotrac II specification, which is also a type of DEXRON VI. Always verify the exact fluid requirement for your specific transfer case in your owner's manual.

Capacity: Approximately 1.5 - 2.0 quarts. Verify in your owner's manual for the precise capacity.

Intervals and Pitfalls: Transfer case fluid should be inspected regularly and changed according to the schedule in your owner's manual, especially if you frequently engage 4WD or perform heavy towing. Using an incorrect fluid can lead to premature wear or failure of the transfer case components.

Front Differential

The front differential for your 2019 GMC Sierra 1500 requires SAE 75W-90 Synthetic Axle Lubricant meeting GM Spec 9986115.

Capacity: Approximately 1.7 - 1.9 quarts. Always confirm the exact capacity in your owner's manual.

Intervals and Pitfalls: Differential fluid should be changed according to your vehicle's maintenance schedule, particularly if you engage in heavy towing or off-road driving. Using conventional gear oil or fluid with an incorrect viscosity or specification can lead to accelerated wear of the differential components.

Rear Differential

The rear differential on the 2019 GMC Sierra 1500 typically uses SAE 75W-90 Synthetic Axle Lubricant meeting GM Spec 9986115. For vehicles equipped with heavy-duty trailering packages or certain locking differentials, some models may specify SAE 75W-140 Synthetic Axle Lubricant also meeting GM Spec 9986115. It is crucial to verify the correct fluid type and viscosity for your specific rear differential in your owner's manual.

Capacity: Approximately 2.5 - 2.8 quarts. Verify the exact capacity in your owner's manual.

Intervals and Pitfalls: Similar to the front differential, the rear differential fluid should be maintained per the owner's manual, with more frequent changes recommended for severe service conditions. If your vehicle has a limited-slip or locking differential, ensure the chosen fluid explicitly states compatibility or contains the necessary friction modifiers. While GM Spec 9986115 usually covers this, double-checking is wise to prevent chatter or improper operation of the differential.

Brake Fluid

Your 2019 GMC Sierra 1500 requires either DOT 3 or DOT 4 Motor Vehicle Brake Fluid. Both are glycol-ether based fluids. While DOT 4 has a higher wet and dry boiling point than DOT 3, they are generally compatible for mixing, but it's always best to use the fluid specified in your owner's manual or to completely flush the system when switching types.

Capacity: As needed to fill the master cylinder reservoir.

Intervals and Pitfalls: Brake fluid is hygroscopic, meaning it absorbs moisture over time, which lowers its boiling point and can lead to corrosion in the braking system. Many manufacturers recommend flushing the brake fluid every 2-3 years, regardless of mileage. Never use DOT 5 (silicone-based) brake fluid, as it is incompatible with systems designed for DOT 3/4 and can cause seal damage and brake failure. Always keep the brake fluid reservoir cap securely tightened to minimize moisture absorption.

Power Steering Fluid

The 2019 GMC Sierra 1500 typically utilizes an electronically assisted power steering system. This means there is no traditional hydraulic power steering pump or fluid reservoir to maintain. The system is electric, providing assistance without the need for hydraulic fluid.

Capacity: N/A

Intervals and Pitfalls: No fluid-related maintenance is required for the power steering system.

Washer Fluid

For the windshield washer system, your 2019 GMC Sierra 1500 uses standard pre-mixed windshield washer solvent. These typically contain detergents and antifreeze agents to prevent freezing in cold weather.

Capacity: Approximately 1 gallon.

Intervals and Pitfalls: Top off as needed. Avoid using plain water, especially in freezing temperatures, as it can freeze and damage the washer system components. Specialty bug remover or de-icing washer fluids can be used based on seasonal needs.

Diesel Exhaust Fluid (DEF)

For 2019 GMC Sierra 1500 models equipped with the 3.0L Duramax Diesel engine, Diesel Exhaust Fluid (DEF) is required for the Selective Catalytic Reduction (SCR) system. The DEF must meet the API CK-4 standard and ISO 22241 (which ensures purity and concentration).

Capacity: Approximately 5.0 gallons.

Intervals and Pitfalls: The DEF tank will need to be refilled periodically. The vehicle will provide warnings when the DEF level is low. Only use high-quality, certified DEF. Using contaminated or non-compliant DEF can damage the SCR system, lead to reduced engine power (limp mode), and ultimately costly repairs. Never put DEF into the diesel fuel tank, and never put diesel fuel into the DEF tank. Store DEF properly as recommended by the manufacturer, as it can degrade over time and with exposure to extreme temperatures.

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