2016 GMC Sierra 2500HD Fluid Type Specs

Quick Reference

Fluid	Type/Spec	Capacity
Engine Oil (Gas)	SAE 5W-30, dexos1 Gen2	6.0 US Quarts
Engine Oil (Diesel)	SAE 5W-40 or 15W-40, dexos2, API CJ-4	~10 US Quarts
Engine Coolant	Dex-Cool ( silicate-free OAT), Orange	~16-17 US Quarts
Transmission Fluid	Dexron VI	~11-13 US Quarts
Transfer Case	AutoTrak II or Dexron VI	~1.5-2.0 US Quarts
Front Differential	SAE 75W-90, GM Part No. 89021677	~1.8-2.0 US Quarts
Rear Differential	SAE 75W-90, GM Part No. 89021677	~2.5-3.0 US Quarts
Brake Fluid	DOT 3 or DOT 4	As needed
Power Steering Fluid	Dexron VI	As needed
Washer Fluid	All-season washer fluid	~1 US Gallon
DEF (Diesel Exhaust Fluid)	ISO 22241 (API DEF certified)	7 US Gallons

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Engine Oil

Gasoline Engines (6.0L Vortec V8): For the 2016 GMC Sierra 2500HD equipped with the 6.0L Vortec gasoline engine, the factory-recommended engine oil is SAE 5W-30. It must meet the dexos1 Gen2 specification (GM Standard GM6094M). This specification ensures proper lubrication, protection against wear, excellent cold-weather performance, and helps maintain fuel economy. Always look for the official dexos1 Gen2 logo on the oil bottle. Capacity is approximately 6.0 US Quarts with a filter change.

Diesel Engines (6.6L Duramax LML): For the 6.6L Duramax LML diesel engine, the recommended engine oil is SAE 5W-40 or 15W-40, depending on ambient temperature conditions. It needs to meet the dexos2 specification (GM Standard GM6094M for diesel engines) and be rated API CJ-4 or later. CJ-4 oils are specifically formulated for engines with diesel particulate filters (DPFs) to reduce ash content, which can clog the filter. Capacity is substantial, typically around 10 US Quarts. Always consult your owner's manual for the most accurate and up-to-date capacity information and temperature-based viscosity recommendations.

Intervals and Pitfalls: Engine oil and filter should be changed according to the Oil Life Monitoring (OLM) system, typically every 7,500-10,000 miles or annually, whichever comes first. For diesel engines, severe duty cycles (towing, heavy hauling, extreme temperatures) may necessitate more frequent changes. Always use a high-quality oil filter to match the extended drain intervals of synthetic oils. Never mix different oil specifications.

Engine Coolant

Your 2016 GMC Sierra 2500HD uses a silicate-free Organic Acid Technology (OAT) coolant, commonly known as Dex-Cool. This coolant is typically orange/red in color. Dex-Cool is designed for extended-life performance, offering corrosion protection for up to 5 years or 150,000 miles under normal driving conditions. It meets GM's specific requirements for aluminum engine components.

Intervals and Pitfalls: The coolant should be replaced per the manufacturer's schedule, typically every 5 years or 150,000 miles. It is crucial never to mix Dex-Cool with traditional green (silicate-based) or hybrid OAT (HOAT) coolants. Mixing can lead to silicate dropout, gel formation, and severe clogging of the cooling system, potentially causing overheating and costly damage. Always use distilled water when mixing concentrate, though pre-mixed 50/50 solutions are widely available and convenient.

Transmission Fluid

Both the standard automatic transmission (6L90) and the Allison 1000 series automatic transmission in the 2016 GMC Sierra 2500HD specify Dexron VI (DEXRON®-VI) automatic transmission fluid. This is a synthetic fluid developed by General Motors to provide improved friction durability, wear protection, and viscosity stability compared to older Dexron specifications. It is backward-compatible with older Dexron requirements, but never use older Dexron fluids where Dexron VI is specified.

Intervals and Pitfalls: Transmission fluid change intervals can vary significantly based on usage (towing, heavy hauling, frequent stop-and-go driving). For severe service, intervals typically range from 50,000 to 75,000 miles, while normal service might extend to 100,000 miles or more. Always verify the specific interval in your owner's manual. Using universal ATFs or fluids not explicitly meeting the Dexron VI specification can lead to premature wear, shudder, and transmission failure. Capacities can range from 11 to 13 US Quarts for a drain and fill, but a full flush would require more.

Transfer Case Fluid

For the 2016 GMC Sierra 2500HD, the transfer case fluid depends on the specific transfer case installed. Many models utilize GM AutoTrak II Fluid (GM Part No. 88902167). This is a blue-colored fluid specifically formulated for GM's AutoTrak transfer cases to ensure smooth operation and prevent shudder. However, some newer transfer cases may specify Dexron VI automatic transmission fluid. Always consult your owner's manual or OEM service information to confirm the correct fluid for your specific transfer case.

Intervals and Pitfalls: Transfer case fluid should typically be changed every 50,000-100,000 miles, or more frequently under severe operating conditions. Using the incorrect fluid can lead to premature wear, noisy operation, and potential transfer case failure. Capacities are usually around 1.5 to 2.0 US Quarts.

Differential Fluid (Front & Rear)

Both the front and rear differentials in the 2016 GMC Sierra 2500HD typically require SAE 75W-90 synthetic gear lubricant. General Motors often specifies their own part number for this, such as GM Part No. 89021677 (ACDelco 10-4016). This fluid provides excellent wear protection and thermal stability under varying loads and temperatures. Some heavy-duty differentials may benefit from a 75W-140 fluid, especially for extreme towing, but 75W-90 is standard. Verify in your owner's manual.

Limited Slip Differentials (LSD): If your Sierra is equipped with a limited slip differential (which is less common on heavy-duty trucks but worth checking), a friction modifier additive may be required in conjunction with the gear oil to prevent chatter and ensure smooth operation of the clutch packs. Many modern synthetic gear oils designed for LSD applications already contain the necessary friction modifiers; otherwise, it must be added separately.

Intervals and Pitfalls: Differential fluid should generally be changed every 50,000-100,000 miles, or more frequently if regularly towing heavy loads or driving through deep water. Failing to change differential fluid can lead to excessive wear, overheating, and eventual differential failure. Always ensure the differential is filled to the correct level.

Brake Fluid

The 2016 GMC Sierra 2500HD uses a DOT 3 or DOT 4 brake fluid. DOT 4 offers a higher boiling point than DOT 3, which can be beneficial for vehicles under heavy braking or towing. Both are glycol-ether based and are compatible, meaning you can top off DOT 3 with DOT 4, but for best performance, a full flush to DOT 4 is recommended if upgrading.

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 brake system. It is recommended to flush the brake fluid every 2-3 years regardless of mileage. Never use DOT 5 (silicone-based) fluid, as it is incompatible with systems designed for DOT 3/4 and will cause seal damage. Always use new fluid from a sealed container.

Power Steering Fluid

Many 2016 GMC Sierra 2500HD models with hydraulic power steering specify Dexron VI automatic transmission fluid for the power steering system. This is common for many GM vehicles and ensures proper operation and longevity of the power steering pump and other components.

Intervals and Pitfalls: Power steering fluid does not have a strict replacement interval but can become contaminated or degrade over time, leading to stiff steering or pump noise. If the fluid appears dark, burnt, or contains debris, it should be flushed and replaced. Avoid using generic power steering fluids unless they explicitly state compatibility with Dexron VI.

Washer Fluid

Any good quality all-season washer fluid is suitable for the 2016 GMC Sierra 2500HD. It's best to use fluids that offer freeze protection suitable for your climate and contain cleaning agents to effectively remove bugs, road grime, and other debris from the windshield.

Intervals and Pitfalls: Simply refill as needed. In freezing climates, ensure you are using a fluid rated for low temperatures to prevent freezing in the reservoir and lines, which can cause damage to the pump and hoses.

DEF (Diesel Exhaust Fluid)

For diesel models (6.6L Duramax LML), the Diesel Exhaust Fluid (DEF) must meet the ISO 22241 standard. This standard ensures the purity and concentration of the urea solution, which is critical for the proper operation of the Selective Catalytic Reduction (SCR) system. Look for products that are API DEF certified.

Intervals and Pitfalls: DEF is consumed continually as the vehicle operates, and the driver information center will indicate when a refill is needed. The tank capacity is 7 US Gallons. Only use DEF that meets the ISO 22241 standard. Never put DEF in the diesel fuel tank or diesel fuel in the DEF tank, as this will cause severe and costly damage. Store DEF in a cool, dry place and be aware of its shelf life, as it can degrade over time.

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