2014 Kenworth T680 Fluid Type Specs

Quick reference

Engine Oil

For the 2014 Kenworth T680, engine oil specifications are primarily dictated by the engine installed. Most T680s from this era would be equipped with a PACCAR MX-13, Cummins ISX15, or a similar heavy-duty diesel engine.

The primary specification to follow is API CJ-4 or the newer API CK-4. These certifications indicate oils suitable for high-speed, four-stroke cycle diesel engines designed to meet 2010 model year on-highway and Tier 4 non-road exhaust emission standards and are formulated for use in all applications with diesel fuels ranging in sulfur content up to 500 ppm.

Regarding viscosity, SAE 15W-40 is the most common and recommended multi-grade oil for a wide range of operating temperatures in commercial trucking applications. However, specific engine manufacturers may allow for other viscosities like 10W-30 or 5W-40 based on ambient operating temperatures and engine design. Always refer to the engine's owner's manual for the most precise recommendation for your operating climate.

Capacity: Engine oil capacity is significant in heavy-duty diesel engines. For a PACCAR MX-13, typical capacity can range from 42 to 45 quarts, including the filter. Cummins ISX engines have similar capacities. Always verify the exact capacity with your engine's dipstick and owner's manual during an oil change.

Intervals & Pitfalls: Oil change intervals for heavy-duty trucks can vary substantially based on application, engine hours, mileage, and oil analysis results. Following the manufacturer's recommended intervals is crucial, which can range from 20,000 to 75,000 miles or more with extended drain oils and proper filtration. Regular oil analysis is highly recommended to optimize drain intervals and detect potential engine issues early. Using conventional automotive gasoline engine oils (e.g., API SN, SP) in a diesel engine is a common pitfall and can lead to premature engine wear and catalytic converter damage due to differing additive packages.

Engine Coolant

Kenworth trucks, especially those with PACCAR engines, typically use an Organic Acid Technology (OAT) Extended Life Coolant (ELC). The factory fill for a 2014 Kenworth T680 with a PACCAR engine would generally be a PACCAR ELC Coolant, which is usually red or purple in color.

Key specifications to look for include TMC RP 329 and ASTM D6210. These specifications ensure the coolant meets the rigorous demands of heavy-duty diesel engines, providing excellent protection against cavitation, corrosion, and scaling.

Capacity: Coolant capacity varies widely depending on the specific cooling system configuration, radiator size, and whether the truck is equipped with an auxiliary heater or sleeper unit. It's best to consult the service manual or visually inspect the reservoir level.

Intervals & Pitfalls: ELC coolants offer extended service intervals, often up to 600,000 miles, 12,000 hours, or 6 years, with proper maintenance and inhibitor top-offs. The most critical pitfall is mixing different types of coolants, especially OAT with Conventional or Hybrid OAT (HOAT) coolants. This can lead to a chemical reaction that depletes the corrosion inhibitors, forms gel-like substances, and can cause severe damage to the cooling system and engine. Always use the specified OAT ELC coolant and never mix colors, as color is often an indicator of chemistry.

Transmission Fluid

The Kenworth T680 could be equipped with various transmissions, primarily Eaton Fuller manual transmissions or Allison automatic transmissions.

For Eaton Fuller Manual Transmissions: The recommended fluid is typically Eaton PS-386, a synthetic gear lubricant designed for extended drain intervals and improved fuel economy. Many Eaton transmissions also permit the use of various synthetic 50-weight transmission fluids that meet Eaton's specifications. Always verify the specific fluid requirements for your exact transmission model, as some older units may use different specifications.

For Allison Automatic Transmissions: If your T680 is equipped with an Allison automatic transmission (e.g., 3000 or 4000 series), the fluid specification will generally be Allison TES-295 or the newer Allison TES-389. TES-295 is a premium fully synthetic fluid designed for extended drain intervals, while TES-389 is also a synthetic option providing excellent performance. Never use