2014 Chevrolet Silverado 2500HD Fluid Type Specifications

As an ASE-certified master technician, I can tell you that heavy-duty trucks like the 2014 Chevrolet Silverado 2500HD are built to take a beating, but they absolutely depend on the right fluids to survive. Whether you are hauling heavy equipment with the 6.6L Duramax diesel or running job site materials with the 6.0L Vortec gas engine, using the incorrect fluid specification can lead to catastrophic failure and voided warranties.

Below is your complete factory-spec fluid guide for the 2014 Chevrolet Silverado 2500HD.

Quick reference

Fluid	Type/Spec	Capacity
Engine Oil (6.0L V8 Gas)	5W-30 (dexos1 Gen 3 / API SP)	6.0 qts (with filter)
Engine Oil (6.6L V8 Diesel)	15W-40 or 5W-40 (API CK-4 / dexosD)	10.0 qts (with filter)
Engine Coolant	DEX-COOL 50/50 mixture (Orange OAT)	16.7 qts (Gas) / 25.4 qts (Diesel)
Transmission (6L90 Gas)	DEXRON-VI Automatic Transmission Fluid	6.3 qts (pan drop)
Transmission (Allison Diesel)	DEXRON-VI or TES-295 (TranSynd)	7.4 qts (pan drop)
Transfer Case (4WD)	DEXRON-VI Automatic Transmission Fluid	1.6 qts (verify in manual)
Front Differential	75W-90 Synthetic Axle Lubricant	1.8 qts
Rear Differential (10.5" / 11.5")	75W-90 Synthetic Axle Lubricant	2.7 - 3.0 qts
Brake Fluid	DOT 3 Hydraulic Brake Fluid	Fill to MAX line
Power Steering Fluid	GM Power Steering Fluid (PN 89021184)	Fill to COLD/HOT marks
DEF (Diesel Only)	API Certified Diesel Exhaust Fluid (ISO 22241)	Approx. 5.3 gallons
Washer Fluid	Standard windshield washer solvent	Fill to top

Note: Capacities are approximate. Always verify the final level with the dipstick or fill plug after running the vehicle.

Engine Oil

For the 6.0L Vortec gas engine, GM requires 5W-30 oil that meets the dexos1 specification. While the truck originally called for dexos1 Gen 1, GM has since updated this spec; you should use dexos1 Gen 3 (which also meets API SP standards) for the best protection against low-speed pre-ignition and timing chain wear. The interval is dictated by the Oil Life Monitor (OLM), but as a technician, I recommend not exceeding 5,000 to 7,500 miles if you are towing.

For the 6.6L LML Duramax diesel, use a heavy-duty diesel engine oil. 15W-40 is standard, but if you live in colder climates (below 0°F), a 5W-40 synthetic is highly recommended to prevent cold-start starvation. The oil must meet the API CJ-4 or the newer API CK-4 specification.

Common Pitfall: Never put standard gas-engine oil in your Duramax. It lacks the soot-handling dispersants and high-shear stability required for diesel operation.

Engine Coolant

Both engines in the 2014 Silverado 2500HD require DEX-COOL, which is an Organic Acid Technology (OAT) coolant. It is distinctly orange. The GM spec is GM 6277M.

Common Pitfall: Never mix DEX-COOL with older green (IAT) coolants or yellow/gold (HOAT) coolants. Mixing these will cause the chemical inhibitors to clash, turning the coolant into a thick, muddy gel that will clog your heater core and radiator. If you are flushing the system, use distilled water, never tap water, to prevent mineral scale buildup. Service intervals are generally 150,000 miles or 5 years, whichever comes first.

Transmission Fluid

If you have the 6.0L gas engine, your truck has the 6L90 6-speed automatic transmission. This unit requires DEXRON-VI (GM spec). Do not use universal ATFs; stick to licensed DEXRON-VI for the correct frictional properties to prevent torque converter shudder.

If you have the 6.6L Duramax, you have the renowned Allison 1000 transmission. While GM fills these with DEXRON-VI at the factory, Allison heavily recommends using a fluid that meets the TES-295 specification (like Castrol TranSynd) for extreme heavy-duty use. TES-295 fluids are fully synthetic and offer vastly superior resistance to heat degradation when towing heavy loads.

Transfer Case

Four-wheel-drive models of the 2014 2500HD use a heavy-duty transfer case that takes DEXRON-VI automatic transmission fluid. Note that this is different from older light-duty GM trucks that used Auto-Trak II. Check your specific RPO codes and owner's manual to verify, but DEXRON-VI is the standard for the heavy-duty BorgWarner/Magna cases used in this era. Change this fluid every 50,000 miles, or every 25,000 miles if you frequently drive in severe 4x4 conditions.

Front and Rear Differentials

Both the front and rear axles require 75W-90 Synthetic Axle Lubricant (GM Part No. 89021677 or equivalent API GL-5).

Common Pitfall: GM’s heavy-duty 10.5-inch and 11.5-inch rear axles feature the G80 automatic locking differential (often called a "Gov-Loc"). Unlike clutch-based Limited Slip Differentials (LSDs) used by other brands, the G80 relies on a flyweight mechanism. Do not add friction modifiers or LSD additives to the rear differential. Additives can make the fluid too slippery, preventing the locker mechanism from engaging properly.

Brake Fluid

The hydraulic brake system uses DOT 3 Brake Fluid. Because heavy-duty trucks generate immense heat during braking—especially when towing—the brake fluid degrades and absorbs moisture over time. Flushing the brake fluid every 2 to 3 years is a cheap insurance policy against internal corrosion and a spongy brake pedal.

Power Steering Fluid

GM recommends specialized GM Power Steering Fluid (Part No. 89021184). Some aftermarket sources suggest using ATF, but to ensure the longevity of the hydro-boost system (which runs off the power steering pump in these heavy-duty trucks), stick to the dedicated GM spec. The hydro-boost system requires stable fluid pressure to provide power assist to your brakes.

Diesel Exhaust Fluid (DEF)

Duramax models are equipped with a Selective Catalytic Reduction (SCR) system to reduce NOx emissions. You must use Diesel Exhaust Fluid that is API certified and meets the ISO 22241 standard.

Common Pitfall: DEF is mostly deionized water and urea. It has a shelf life, particularly in extreme heat. Never buy DEF that has been sitting in direct sunlight at a gas station, and do not overfill the tank in freezing weather, as DEF expands when it freezes.

Keeping up with these factory specifications ensures your Chevy 2500HD remains a reliable workhorse for years to come. If you're not comfortable performing these services yourself or don't want to deal with disposing of heavy-duty fluid quantities, seek out a professional.

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