2022 Freightliner M2 106 Fluid and Lubricant Specifications

Quick Reference: Fluid Specifications

Fluid	Type/Specification	Capacity
Engine Oil	API CK-4; SAE 10W-30 or 15W-40	Varies by engine (e.g., ~12-45 quarts)
Engine Coolant	OAT ELC; Phosphate-Free	Varies by configuration (~10-14 gallons)
Automatic Transmission Fluid	Allison TES 668	Varies by transmission model
Manual Transmission Fluid	SAE 50 or Eaton PS-386/PS-278	Varies by model
Rear Axle / Differential	SAE 75W-90, 80W-140, or 75W-140	Varies by axle model
Brake Fluid	DOT 4	As required
Power Steering Fluid	ATF (Dexron III/VI) or PSF	As required
Windshield Washer Fluid	Winter/Summer Blend	~1-2 gallons
Diesel Exhaust Fluid (DEF)	API Certified / ISO 22241	Varies by tank size (e.g., 6-23 gallons)

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Engine Oil

The Freightliner M2 106 is available with several engine options from Cummins and Detroit Diesel. The correct engine oil is critical for protecting these heavy-duty engines from soot, wear, and thermal breakdown.

• Specification: Use a high-quality diesel engine oil meeting API Service Category CK-4. This is the current industry standard, offering superior protection against oxidation, shear, and aeration compared to older CJ-4 oils.
• Viscosity: The most commonly recommended viscosities are SAE 15W-40 for all-around performance and SAE 10W-30 for improved fuel economy and cold-weather starting. For specific Detroit Diesel engines (like the DD5 and DD8), their proprietary DFS 93K222 (for 15W-40) or DFS 93K223 (for 10W-30) specifications are recommended.
• Capacity: Engine oil capacity is entirely dependent on the specific engine installed. For example, a Cummins B6.7 may hold around 12 quarts, while a larger Detroit DD13 can require upwards of 45 quarts. Always verify the exact capacity in your OEM service manual and check the dipstick when filling.
• Interval: Follow the oil change intervals specified by the engine manufacturer, which are often determined by an oil life monitoring system or based on miles, hours, or fuel consumed.

Engine Coolant (Antifreeze)

Protecting a modern diesel engine from corrosion and temperature extremes requires a specific coolant formulation.

• Specification: Use a Nitrited Organic Additive Technology (NOAT) or an Organic Additive Technology (OAT) Extended Life Coolant (ELC). These are typically red or pink in color. The key is to use a phosphate-free, silicate-free formula designed for heavy-duty diesel engines. Look for coolants meeting specifications like Detroit Diesel DFS 93K217 or Cummins CES 14603.
• Common Pitfalls: Never mix coolant types. Adding conventional green or Hybrid OAT (HOAT) coolant to an OAT/NOAT system can cause the additives to "drop out," leading to gel formation, blockages in the radiator and heater core, and severe cooling system damage. If topping off, always use the same type of ELC that is already in the system or distilled water in an emergency.
• Capacity: Cooling system capacity varies widely based on the engine, radiator size, and cab heating configuration, but typically falls in the 10–14 gallon range.

Transmission Fluid

Fluid requirements depend entirely on the transmission installed.

• Automatic Transmissions: Most M2 106 models with an automatic are equipped with an Allison transmission. The current, backward-compatible specification is Allison TES 668. Older specs like TES 295 or TES 389 have been superseded by TES 668, which offers superior thermal stability and drain intervals. Do not use generic Dexron/Mercon ATF unless it explicitly states it is Allison TES 668 approved.
• Manual Transmissions: For Eaton Fuller manual transmissions, use a fluid meeting Eaton PS-386 (formerly PS-164rev7) or a high-quality SAE 50 synthetic transmission fluid. For severe service, Eaton PS-278 may be specified.

Axle & Differential Fluid

Proper gear oil is essential for the longevity of the drive axle(s).

• Specification: Most rear axles will specify a synthetic gear lubricant meeting SAE 75W-90. For heavy-haul or severe-duty applications, a heavier SAE 80W-140 or 75W-140 may be required. Always use a fluid meeting API GL-5 or the axle manufacturer's spec, such as Meritor O-76.
• Limited-Slip Differentials: If the truck is equipped with a limited-slip or locking differential, ensure the gear oil is either formulated for this application or that the correct friction modifier additive is added during the fluid change.

Brake & Power Steering Fluid

• Brake Fluid: The M2 106 uses a hydraulic brake system that requires DOT 4 motor vehicle brake fluid. Never substitute with DOT 3 or DOT 5 (silicone-based) fluid. DOT 4 has a higher boiling point, which is critical for heavy-truck applications.
• Power Steering Fluid: The specification can vary. Many Freightliner models use standard Automatic Transmission Fluid (ATF) meeting a Dexron III or Dexron VI specification. Others may specify a dedicated power steering fluid. Check the reservoir cap or service manual, as using the wrong fluid can damage seals.

Diesel Exhaust Fluid (DEF)

For any 2022 model, DEF is essential for the Selective Catalytic Reduction (SCR) system to function.

• Specification: Use high-quality Diesel Exhaust Fluid that is ISO 22241 compliant and, if in North America, displays the API Certified diesel exhaust fluid mark. DEF is a solution of 32.5% urea in 67.5% de-ionized water.
• Common Pitfalls: Never add anything other than DEF to the DEF tank. Contamination with diesel fuel, water, or any other liquid will destroy the expensive SCR system components. Use clean funnels and containers dedicated solely to DEF transfer.

Windshield Washer Fluid

Use a commercial windshield washer fluid appropriate for the climate. In freezing temperatures, a "winter" blend with a low freezing point is necessary to prevent freeze-up of the reservoir, lines, and nozzles.

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Disclaimer: The information provided here is for general reference only. Fluid specifications and capacities can vary based on the specific engine, transmission, axle, and options equipped on your vehicle. Always consult your owner's manual or official Freightliner/OEM service information for the exact requirements of your 2022 M2 106.

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