2023 Ford F-350 Super Duty — Fluid Type Specs

Quick reference

Fluid	Type/Spec	Capacity
Engine oil (gas 6.8L/7.3L)	5W-30 meeting Ford WSS-M2C961-A1 (API SP/ILSAC GF-6)	6.8L: ~7–8 qt; 7.3L: ~8 qt (with filter) — verify by engine
Engine oil (diesel 6.7L)	10W-30 (preferred) or 5W-40 full synthetic meeting Ford WSS-M2C171-F1 (API CK-4)	~12–13 qt (with filter) — verify VIN/OM
Engine coolant	Motorcraft Yellow P-OAT, meeting Ford WSS-M97B57-A1 (yellow)	~6–8 gal total system depending on engine/body — verify
Automatic transmission (10‑speed TorqShift)	MERCON ULV ATF meeting Ford WSS-M2C949-A (Motorcraft XT-12-QULV)	Service refill ~7–10 qt; dry fill ~16–20 qt — verify by transmission tag
Transfer case (4×4)	Motorcraft Transfer Case Fluid (XL‑12) meeting WSS‑M2C203‑A; some units specify MERCON LV (WSS‑M2C938‑A) — verify	~2.0–3.0 qt
Front differential (4×4)	75W‑140 full-synthetic API GL‑5 gear oil	~2.0–3.0 qt depending on axle
Rear differential	75W‑140 full-synthetic API GL‑5 gear oil; add 4 oz Motorcraft XL‑3 friction modifier only if clutch‑type LSD (not for e‑locker)	~3.0–4.5 qt depending on axle ratio/housing
Brake fluid	DOT 4 (Low Viscosity) meeting Ford WSS‑M6C65‑A2	System ~1–2 qt for full flush
Power steering	MERCON LV ATF meeting Ford WSS‑M2C938‑A (check cap/OM; some chassis cabs may differ)	~2–3 qt for full exchange
Washer fluid	Any quality premixed windshield washer fluid appropriate for climate	Reservoir ~1.0–1.5 gal (varies by body)
Diesel Exhaust Fluid (6.7L only)	ISO 22241 / DIN 70070 compliant DEF (32.5% urea)	~5–7.5 gal typical, varies by wheelbase/body — verify

Note: Capacities vary with engine (6.8L gas V8, 7.3L gas V8, 6.7L Power Stroke), axle, cab/bed, and 4×2 vs 4×4. Always verify in the owner’s manual or OEM service information.

Engine oil (gasoline 6.8L/7.3L)

• Spec: 5W-30 that meets Ford WSS-M2C961-A1 (API SP/ILSAC GF-6). Use oils explicitly stating this spec on the label.
• Capacity: Approximately 6.8L: ~7–8 quarts; 7.3L: ~8 quarts with filter. Verify by engine and VIN.
• Interval: Follow the Intelligent Oil-Life Monitor. Severe service (heavy towing, idling, dust) often 5,000–7,500 miles.
• Tips/pitfalls: Do not substitute 5W-20 or 0W-20. Use a quality filter meeting Ford spec. Keep oil level at the upper hash after filter fill to protect under sustained grades/towing.

Engine oil (diesel 6.7L Power Stroke)

• Spec: 10W-30 (preferred) or 5W-40 full synthetic meeting Ford WSS-M2C171-F1 and API CK-4. Do not use API FA-4.
• Capacity: ~12–13 quarts with filter depending on calibration/build.
• Interval: Use the dash reminder; severe-duty/towing often 5,000 miles or per oil analysis.
• Tips/pitfalls: Cold climates or heavy towing may benefit from 5W-40. Always prime the new oil filter. Watch soot loading if idled extensively.

Engine coolant

• Spec: Motorcraft Yellow (P-OAT) coolant meeting Ford WSS-M97B57-A1. Color: Yellow.
• Capacity: Roughly 6–8 gallons total system, varying by engine and heater configurations.
• Interval: Typically up to 10 years/200,000 miles initial fill, then 5 years/100,000 miles thereafter. Confirm in OM for your configuration.
• Tips/pitfalls: Do not mix with older Ford Orange (WSS-M97B44-D2) or green conventional coolants. If mixing is unavoidable, perform a complete flush. Use only distilled water when diluting concentrate.

Automatic transmission (10-speed TorqShift)

• Spec: MERCON ULV ATF meeting Ford WSS-M2C949-A (Motorcraft XT-12-QULV). Some service publications and earlier units may reference MERCON LV on certain applications; use exactly what your dipstick/tags/OM specify.
• Capacity: Service refill typically ~7–10 quarts; dry fill around ~16–20 quarts depending on cooler lines and PTO, if equipped.
• Interval: Normal service can be very long; under severe duty (heavy towing, heat, PTO use) plan 30,000–60,000-mile fluid/filter service.
• Tips/pitfalls: Never use “universal” ATF or MERCON V. Level must be checked at the specified fluid temperature via the service procedure—over/underfill can cause shift and durability issues.

Transfer case (4×4)

• Spec: Motorcraft Transfer Case Fluid (XL-12) meeting WSS‑M2C203‑A for many BorgWarner units used on Super Duty. Some 2023 trucks specify MERCON LV (WSS-M2C938-A) instead. Verify by model tag and OM.
• Capacity: ~2.0–3.0 quarts.
• Interval: Inspect every 30,000 miles; change 60,000–100,000 miles severe duty or after deep-water immersion.
• Tips/pitfalls: Do not fill with gear oil. Use only the specified fluid to protect chain, bearings, and clutch packs (if TOD).

Front differential (4×4)

• Spec: 75W-140 full-synthetic API GL-5.
• Capacity: ~2.0–3.0 quarts depending on axle (e.g., Dana Super 60 variants) and hubs.
• Interval: 100,000 miles normal; 30,000–60,000 miles severe use (towing, dirt roads), or after water crossings.
• Tips/pitfalls: Clean the magnet and check for water intrusion (milky fluid) on trucks used off-road.

Rear differential

• Spec: 75W-140 full-synthetic API GL-5 across most F-350 axles. Limited-slip additive: add Motorcraft XL-3 friction modifier only if equipped with a clutch-type limited-slip. Electronic locking differentials typically do NOT use additive.
• Capacity: ~3.0–4.5 quarts depending on axle (Sterling/Dana M275/M300), ratio, and cover depth.
• Interval: 100,000 miles normal; 30,000–60,000 miles severe duty or frequent towing.
• Tips/pitfalls: Overfilling can aerate fluid. If towing heavy in hot climates, 75W-140 is preferred over 75W-90.

Brake fluid

• Spec: DOT 4 (Low Viscosity) meeting Ford WSS‑M6C65‑A2.
• Capacity: Plan on ~1–2 quarts for a complete flush/bleed.
• Interval: Replace every 2–3 years regardless of mileage, or sooner if testing shows >3% moisture or low boiling point.
• Tips/pitfalls: Keep fluid off painted surfaces. Do not mix DOT 5 silicone with DOT 3/4/5.1 systems.

Power steering

• Spec: MERCON LV ATF meeting WSS‑M2C938‑A (check reservoir cap and OM; some chassis-cab/hydroboost configurations may specify differently).
• Capacity: ~2–3 quarts for a full exchange.
• Interval: Inspect each service; change 60,000–100,000 miles or if dark/contaminated.
• Tips/pitfalls: Use only the specified ATF; do not substitute generic “power steering fluid” unless Ford-approved for your VIN.

Washer fluid

• Spec: Any reputable premixed washer fluid appropriate for climate. Winter blends with methanol/ethanol for freeze protection.
• Capacity: Typically 1.0–1.5 gallons depending on body.
• Tips: Never use plain water in freezing climates; keep the strainer screen clear.

Diesel Exhaust Fluid (DEF) — 6.7L Power Stroke only

• Spec: ISO 22241 (DIN 70070) compliant DEF (32.5% urea).
• Capacity: Typically ~5–7.5 gallons depending on cab/bed/wheelbase; verify in OM.
• Interval: Top off as needed; consumption commonly 2–3% of diesel usage (higher under heavy load/regeneration).
• Tips/pitfalls: Store sealed, out of sun, 23–77°F. DEF freezes at 12°F; the truck’s system is designed to thaw it. Do not add additives or water. Use clean funnels to avoid SCR contamination.

Always verify fluid specs and fill capacities in your owner’s manual or OEM service information for your specific VIN and configuration. Using the exact Ford specification (WSS-…) protects your powertrain and preserves warranty coverage.

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