How to Add Gear Fluid to a Ford F150

by Thomas West

The F150 is a half-ton, full-size pickup truck made by the Ford Motor Company. Gear oil is used in the rear axle differential to lubricate the bearings and ring and pinion gears. F150s that are equipped with four-wheel drive also have a front differential that is very similar to the rear. If a leak is detected, the gear oil should be checked. Low fluid level in the differential may cause it to overheat and fail.

Crawl under the rear of the vehicle. Locate the differential, which is at the center of the vehicle between the front or rear wheels, depending on which differential you wish to check. (Only four-wheel drive F150s have a front differential.)

Locate the threaded plug, which is mounted approximately midway between the top and bottom of the differential at the front.

Place the square end of a ratchet wrench into the threaded plug in the differential. Turn the wrench in a counterclockwise direction to loosen and remove the plug. Wipe any oil or metal shavings from the plug with a rag and place it aside.

Check the level of oil by sticking a finger into the hole where the plug was removed. Add oil if the level is below the bottom of the hole. Do this by inserting the nozzle of the gear oil container into the hole and squeezing until the fluid is at the correct level.

Thread the plug back into the hole and tighten with a ratchet wrench in a clockwise direction. Wipe up any oil spills on the differential with a rag.

Tip

  • check Most Ford differentials are lubricated for life and the fluid does not need to be checked or changed unless a leak is suspected or the differential has been submerged in water.

Warning

  • close Use only the type of gear oil in your differential specified in your owner's guide. Your differential could be damaged by using the wrong type or viscosity of gear oil. Ford calls for a synthetic gear oil to be used in the rear differential on most later model F150s. The type of oil used in the front differential on four-wheel drive models may be different than what is used in the rear axle. For instance, the owner's guide of the 2002 F150 calls for synthetic 75W-140 gear oil in the rear axle, while the front axle uses 75W-90 non-synthetic 4x4 gear oil.

Items you will need

References

About the Author

This article was written by the It Still Runs team, copy edited and fact checked through a multi-point auditing system, in efforts to ensure our readers only receive the best information. To submit your questions or ideas, or to simply learn more about It Still Runs, contact us.