2020 Freightliner M2 106: Fluid Type and Capacity Specs

Quick Reference

Fluid	Type/Spec	Capacity
Engine Oil	15W-40, API CK-4	12-45 quarts (verify engine)
Engine Coolant	OAT, nitrite-free	12-14 gallons (verify engine)
Automatic Transmission Fluid	Allison TES 295 / TES 668	19-29 quarts (verify transmission)
Manual Transmission Fluid	Eaton PS-386	28 pints
Transfer Case Fluid	N/A	N/A
Front Differential Fluid	80W-90	15-18 pints
Rear Differential Fluid	75W-90	25-35 pints
Brake Fluid	DOT 4	Varies
Power Steering Fluid	ATF	3-4 quarts
Washer Fluid	-	6 quarts
Diesel Exhaust Fluid (DEF)	ISO 22241	13-23 gallons

Engine Oil

For the 2020 Freightliner M2 106, the recommended engine oil is a 15W-40 heavy-duty diesel oil that meets API service category CK-4. Depending on the installed engine (Cummins B6.7 or Detroit DD5/DD8), the oil capacity can range from 12 to 45 quarts. Always verify the engine and check the dipstick when filling. Using a high-quality CK-4 oil is crucial for protecting modern diesel engines equipped with complex emissions systems.

Engine Coolant

The M2 106 requires an Organic Acid Technology (OAT), nitrite-free, extended-life coolant. Do not mix with other coolant types, as this can cause gelling and lead to cooling system blockages. The system capacity is typically between 12 and 14 gallons, but this can vary based on the engine and radiator configuration. Always top off with a 50/50 mix of distilled water and the correct OAT coolant.

Transmission Fluid

For models equipped with an Allison automatic transmission, use a fluid that meets Allison TES 295 or the newer TES 668 specification. For manual transmissions, Eaton PS-386 is the correct fluid. Fluid capacity varies significantly based on the specific transmission model, so it's essential to verify the correct fill level. Never use a universal ATF, as this can cause irreparable damage to the transmission.

Differential Fluid

The front differential on 4x4 models requires 80W-90 gear oil. The rear differential uses a 75W-90 synthetic gear oil. Capacities vary, but the front is typically around 15-18 pints, while the rear can be 25-35 pints. Always check the fluid level on a level surface.

Brake Fluid

The M2 106 uses DOT 4 brake fluid. The system should be flushed and refilled every two years to prevent moisture contamination, which can lead to brake failure. The total capacity will vary, but a full flush will typically require at least one quart of new fluid.

Power Steering Fluid

Use a quality automatic transmission fluid (ATF) in the power steering system. The capacity is around 3-4 quarts. Check the fluid level with the engine off to get an accurate reading.

Washer Fluid

Use any standard automotive windshield washer fluid. The reservoir holds approximately 6 quarts.

Diesel Exhaust Fluid (DEF)

For the selective catalytic reduction (SCR) system, you must use Diesel Exhaust Fluid (DEF) that is API-certified and meets the ISO 22241 standard. The DEF tank size can be 13 or 23 gallons. Using a non-compliant fluid can damage the SCR system, leading to costly repairs.

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