An axle differential may be one of the most overlooked items when it comes to vehicle maintenance. A differential transfers power from the drive shaft to the axles. A 2000 Ford F250 has a heavy-duty rear differential that may have a limited-slip feature on some models. Four-wheel-drive F250s also have a front differential. The differentials on these trucks are relatively maintenance-free, but Ford recommends that you check the differential lubricant level under certain conditions.
Park the truck on a level surface and apply the parking brake.
Slide under the vehicle and locate the filler plug on the differential housing near where the drive shaft is attached to the differential. Clean the plug and the surrounding differential housing with a rag so dirt particles will not enter the differential through the opening when you remove the filler plug.
Insert the square end of a 3/8 inch drive ratchet wrench or breaker bar into the square opening in the differential filler plug.
Remove the plug from the differential by turning the wrench handle in a counterclockwise direction.
Observe the fluid level through the filler plug opening. If you cannot see, put on a glove and stick your pinky finger into the hole to check the level. The fluid should come up to the bottom of the opening. Add fluid, if needed.
Wipe the filler plug clean with a rag. Thread the plug back into the differential opening by hand to avoid cross-threading it. Tighten the plug further with the ratchet wrench or breaker bar.
