2014 Chevrolet Silverado 3500HD Complete Fluid Specifications

As an ASE-certified master technician, I know that keeping a heavy-duty truck like the 2014 Chevrolet Silverado 3500HD on the road requires strict adherence to factory fluid specifications. Whether your truck is equipped with the 6.0L Vortec gas engine or the legendary 6.6L Duramax turbo-diesel, using the right fluid—down to the exact OEM specification number—is the difference between a truck that goes 300,000 miles and one that ends up on a lift with a catastrophic failure.

Below is the definitive fluid specification sheet for the 2014 Chevrolet Silverado 3500HD. Always consult your owner's manual or OEM service information to verify exact capacities based on your specific RPO codes and cooling package.

Quick reference

Fluid	Type/Spec	Capacity
Engine Oil (6.0L Gas)	5W-30 (dexos1™ Gen 3 / API SP)	6.0 qts (5.7 L) with filter
Engine Oil (6.6L Diesel)	15W-40 or 5W-40 (API CK-4 / CJ-4)	10.0 qts (9.5 L) with filter
Engine Coolant	DEX-COOL® (OAT, Orange, GM 6277M)	Gas: ~16.8 qts | Diesel: ~25.4 qts
Transmission (6L90 - Gas)	DEXRON®-VI	~6.3 qts (pan drop)
Transmission (Allison - Diesel)	DEXRON®-VI or Allison TES-295	~7.4 qts (pan drop)
Transfer Case (4WD)	DEXRON®-VI ATF	~1.6 qts (1.5 L)
Front Differential (4WD)	80W-90 Axle Lubricant	~1.8 qts (1.7 L)
Rear Differential	75W-90 Synthetic Gear Oil	3.0 - 4.2 qts (varies by axle)
Brake Fluid	DOT 3 Hydraulic Brake Fluid	Fill to MAX line
Power Steering Fluid	GM Power Steering Fluid (P/N 19329450)	Fill to COLD/HOT marks
DEF (Diesel Only)	ISO 22241 standard	~5.3 gallons (20.0 L)
Windshield Washer Fluid	Standard washer solvent	~1.0 gallon

Engine Oil

6.0L Vortec V8 (Gas)

For the 6.0L gas engine, General Motors specifies 5W-30 engine oil that meets the dexos1™ Gen 3 specification (which supersedes Gen 1 and Gen 2). This spec ensures optimal protection against low-speed pre-ignition (LSPI) and timing chain wear. If dexos1 is unavailable, any API SP full synthetic of the same weight can be used in a pinch, but sticking to the dexos1 spec is highly recommended. The oil change interval is dictated by the Oil Life Monitor (OLM), but as a master tech, I recommend never exceeding 5,000 to 7,500 miles, especially if you tow frequently.

6.6L Duramax V8 (Diesel)

The Duramax requires heavy-duty diesel oil. The factory spec calls for 15W-40 or 5W-40 full synthetic for colder climates (below 0°F). It must meet the API CK-4 standard (which supersedes the original CJ-4 spec for 2014). Proper diesel oil is critical for suspending soot and protecting the variable geometry turbocharger. Change the oil and filter every 5,000 miles or when the OLM indicates, whichever comes first.

Engine Coolant

Both engines require DEX-COOL® (GM 6277M). This is an Organic Acid Technology (OAT) coolant and is distinctively orange.

Master Tech Warning: Never mix DEX-COOL with traditional green (Silicate/IAT) or HOAT (Hybrid) coolants. Mixing coolant types will cause the silicates and organic acids to react, creating a sludgy, gel-like substance that will clog your heater core and radiator, leading to severe engine overheating. Always use a 50/50 mix with distilled water or buy pre-diluted jugs. The factory replacement interval is 5 years or 150,000 miles.

Transmission Fluid

6L90 Automatic (Gas)

The 6L90 transmission uses DEXRON®-VI. Never use universal "multi-vehicle" ATF in these modern transmissions, as the friction modifier package is completely different and can cause shuddering or clutch failure. A standard pan drop and filter change will take around 6.3 quarts.

Allison 1000 Automatic (Diesel)

For the Allison transmission, GM originally shipped these with DEXRON®-VI, but many heavy-duty fleet mechanics and Allison themselves highly recommend upgrading to an Allison TES-295 approved fluid (such as Castrol TranSynd) for extreme towing conditions. TES-295 fluids offer superior shear stability. When replacing the spin-on filter, remember to transfer the magnet to the new filter!

Transfer Case (4WD Models)

If your 3500HD is equipped with four-wheel drive, the transfer case takes standard DEXRON®-VI ATF. Even though it's a gear-driven and chain-driven box, it relies on the low viscosity of ATF for proper lubrication of the internal pump and bearings. Drain and fill requires about 1.6 quarts. Change this fluid every 50,000 miles, or every 25,000 miles if you frequently drive off-road or in 4WD.

Differentials (Front and Rear)

Front Differential

The front independent aluminum differential housing requires 80W-90 Gear Oil. It takes slightly under 2 quarts.

Rear Differential

The massive rear axle on the 3500HD requires 75W-90 Synthetic Gear Oil.

Important Pitfall Note: The 2014 Silverado 3500HD utilizes the GM G80 automatic locking rear differential. Do not add limited-slip friction modifiers. The G80 is a mechanical locking differential (using flyweights and a latching bracket), not a clutch-pack style limited-slip. Adding friction modifiers can actually prevent the locking mechanism from engaging properly.

Brake Fluid

GM specifies Delco Supreme 11 DOT 3 brake fluid. DOT 3 is standard, but you must ensure it is fresh from a sealed bottle. Brake fluid is hygroscopic (it absorbs moisture from the air). Once moisture content exceeds 2-3%, the boiling point of the fluid plummets, which can cause brake fade when hauling a 15,000-pound trailer down a grade. Flush the brake hydraulic system every 2 to 3 years.

Power Steering Fluid

Unlike newer trucks with electronic power steering, the 2014 3500HD still utilizes a hydraulic system, often combined with hydro-boost brakes. Use GM Power Steering Fluid (P/N 19329450 or equivalent). Do not substitute ATF in this system unless strictly directed by an emergency situation, as it can degrade the specific seals used in the hydro-boost system and power steering pump.

Diesel Exhaust Fluid (DEF)

For the 6.6L Duramax, DEF is injected into the exhaust stream to reduce NOx emissions via the Selective Catalytic Reduction (SCR) system. You must use DEF that meets the API Certified ISO 22241 standard.

Master Tech Tip: DEF degrades over time, especially in high heat. If you don't drive your truck often, don't fill the DEF tank to the absolute brim, as old DEF will crystalize and ruin the DEF pump or injector, leading to a costly repair and a dreaded "Speed Limited to 55 MPH" message.

Windshield Washer Fluid

Any standard windshield washer solvent is acceptable. For winter climates, ensure you are using a winter-blend fluid rated for -20°F or lower so the reservoir and lines do not freeze and crack.

Maintaining a heavy-duty truck takes time, knowledge, and the right specifications. If you are ever unsure about a fluid change, it is always best to leave it to the professionals.

Find a trusted shop on Repairius.