2018 Ford F-350 Super Duty Transmission Fluid & Service
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Quick Answer
- Transmission Make/Model: TorqShift 6R140 (automatic)
- OEM Fluid Spec: MERCON® LV Automatic Transmission Fluid
- Drain & Fill Capacity: Approximately 7.6 quarts (varies with pan size and cooler configuration)
- Full Overhaul Capacity: Approximately 17.5 quarts (includes torque converter, cooler, and lines)
- Filter OEM Part Number: Verify with Ford dealer or service manual (typically integrated within the pan or accessible externally)
- Recommended Service Interval: Every 30,000 miles for severe duty/towing, 150,000 miles for normal duty (fluid and filter replacement)
Fluid Type Explained
The 2018 Ford F-350 Super Duty, when equipped with the 6.7L Power Stroke diesel or the 6.2L V8 gasoline engine, utilizes the robust TorqShift 6R140 automatic transmission. This heavy-duty transmission is specifically designed for the demanding work conditions often encountered by Super Duty trucks, including towing heavy loads and frequent hauling. The critical component for its longevity and performance is the correct automatic transmission fluid (ATF).
Ford specifies MERCON® LV Automatic Transmission Fluid for the TorqShift 6R140 transmission. The "LV" in MERCON® LV stands for "Low Viscosity." This fluid is engineered to provide excellent wear protection, consistent shift quality, and optimized fuel economy within the specified operating temperatures of the 6R140. Using any other type of fluid can lead to premature wear, poor shifting, overheating, and ultimately, transmission failure. Always ensure that any fluid used meets the MERCON® LV specification.
Service Procedure
There are generally two methods for servicing the transmission fluid: a drain and fill, and a full fluid exchange (or flush).
Drain & Fill: This method involves draining the transmission fluid from the transmission pan and refilling it with new fluid. This typically replaces only a portion of the total fluid capacity, as a significant amount remains in the torque converter, lines, and cooler. For the 6R140, a drain and fill will replace roughly 7.6 quarts, depending on the pan size and whether it has an auxiliary cooler. While simpler, it doesn
More specs for the 2018 Ford F-350 Super Duty
Oil Capacity & Filter
Capacity, weight, filter PN, drain plug torque, change interval.
Fluid Type Specs
Engine oil, coolant, ATF, diff, brake, PS, DEF — with OEM spec numbers.
Coolant Capacity & Type
Total system capacity, OEM coolant spec, flush interval, bleed tips.
Torque Specifications
Lug nuts, drain plug, caliper, axle nut, plug, key fasteners.
Brake Pad & Rotor Specs
Pad PNs, rotor size, min thickness, caliper torque.
Tire Size & Pressure
OEM size, cold psi, bolt pattern, wheel size, TPMS.
Battery Size & Group
Group size, CCA, AGM/flooded, dimensions, reset note.
A/C Refrigerant & Oil
R-134a or R-1234yf, charge oz, PAG oil spec.
Bulb Sizes (Headlight, Tail, Fog)
Headlight, fog, tail, turn, reverse, interior.
Factory Maintenance Schedule
Service intervals by mileage, severe-duty notes, known issues.
Towing Capacity & Payload
Max tow, payload, GVWR/GCWR, hitch class by trim.
Fuse Box Diagram & Amperage
Fuse box locations, layout, amps, and what each fuse controls.
Serpentine Belt Routing & Length
Belt routing, length, rib count, OEM + aftermarket PNs.
Wheel Alignment Specifications
Camber, caster, toe ranges (front & rear), adjustability notes.
Paint Color Codes
All factory colors with paint codes, sticker location, touch-up tips.
Wiper Blade Sizes
Driver/passenger/rear blade size, attachment, OEM + cross-refs.
Spark Plug Type & Gap
Plug PN, gap, torque, interval by engine.
Transmission & Axle Gear Ratios
Trans gear ratios, axle ratios, RPO codes, tow vs MPG impact.
Key Fob Programming
DIY programming steps, FCC ID, fob PN, battery, transponder.
Same spec — other model years
2014 F-350 Super Duty
2015 F-350 Super Duty
2016 F-350 Super Duty
2017 F-350 Super Duty
2019 F-350 Super Duty
2020 F-350 Super Duty
Maintenance & repair guides
2018 Ford F-350 Super Duty Maintenance Schedule →
Available maintenance guidance; confirm the manufacturer schedule.
Repair planning references →
Plan the scope of work; detailed procedures need configuration-matched evidence.
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