Correct oil level for ford 8.8

[Ryan Petrukovich]

i have an 02 e150 with an 8.8 rear, when i got the van about 2 years ago im PRETTY sure that i checked/topped off the rear diff, just pulled the plug and fill’d her till it ran out.

now i was doing a tire rotation and i noticed the pinion was weeping, i kinda knew this previously but figured hey ill check the level. pulled the plug, no oil. stuck a piece of wire pretty far down in and no oil. so i topped it off til it was about 1/2 or so from the hole. doing this because it seemed like the oil fill hole is much higher on this axle then others i have worked on. at the same time i noticed the vent tube was bending and pinching itself closed, so i changed that hose too.

well now, 2 days later my pinion seal is completely blown. oil just dumping out all over the driveway. im wondering if i over filled it. i started googling and all i can find is very conflicting answers on the correct amount of oil.

pretty frustrating that i cant find out how much oil/how to PROPERLY check the level in a rear axle. or is it just coincidence that my seal has finally decided to give out?

Topic

[Richard Kirshy]

To begin with..
Running a wet seal dry will cause it to fail prematurely.
Most differentials that have a drain plug at the bottom and a fill port somewhere higher.
Usually require you to fill the fluid to the point it weeps out the fill port.
Being that you state: pulled the plug, no oil. stuck a piece of wire pretty far down in and no oil.
I would believe the seal was run dry and was damaged, the fact that it failed within 2 days doesn’t sound so surprising.

[Ryan Petrukovich]

i guess it makes sense, im glad its just the seal and not the pinion bearings i guess..

i found the owners manual buried under the seat and it says 1/4 – 9/16th down from the fill hole.

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