2018-2021 Ford F-150 3.0L Powerstroke Differential Fluid

Differential fluid on the 2018-2021 F-150 3.0L

A gear oil label carries two viscosity grades, one for cold and one for hot. Ford's grade for the diesel F-150's differentials is 75W-85, full-synthetic and hypoid-rated. The oils in this collection are an 80W-90 and a 75W-140 synthetic. Neither is the factory grade, so check what your owner's manual permits for your axle before you choose, or call us and we'll go through it with you.

What we carry

Lucas Oil 10043 Heavy Duty 80W-90 Gear Oil and Royal Purple 01301 Max-Gear 75W-140 Synthetic Gear Oil. Plan your quantity from the published capacities: 2.25 to 2.7 quarts for the rear differential, plus 1.7 to 1.9 quarts if a 4x4 needs the front done too. More 3.0L parts are on the Power Stroke hub.

When to change it

• At the published 150,000-mile interval under normal use.
• Right away after the differentials or transfer case have been submerged, whatever the mileage.
• Whenever you see milky gear oil or hear new bearing noise after water exposure.
• After any differential cover swap, refill to the correct capacity. The electronic locking rear axle takes no special additive per the published schedule.

Fitment notes

This engine was sold in the F-150 only, 2018-2021. Ford doesn't publish its ring-gear size, and F-150s of this era used 8.8-inch and 9.75-inch rear axles, so check the axle tag or door-jamb code if your manual lists different specs by axle.

Frequently asked questions

Can I run 80W-90 or 75W-140 in my F-150 diesel's differential?

Ford's published spec for this truck is 75W-85 full-synthetic hypoid gear oil. The oils here are other grades, so read your owner's manual for what it allows on your axle. If it isn't clear, call the shop with your VIN and axle code and we'll help you sort it out.

How much fluid do I need for a full differential service?

Plan on 2.25 to 2.7 quarts for the rear. A 4x4 needs another 1.7 to 1.9 quarts for the front. Round up so you aren't a quart short with the truck on the lift.

What does milky gear oil mean?

Water got into the differential. Ford's schedule calls for immediate service any time the axles have been submerged, so drain and refill instead of waiting for the mileage interval.

Not sure what fits? Call the shop at the number in the header, or use the fitment checker on any product page. We install everything we sell.