Too much oil in the differential

[Mike Poore]

If the differential gets overfilled, by a lot, and the excess starts exiting from the passinger side rear wheel bearing, is there reason to replace the seals, or will simply lowering the lubricant to the proper level "fix" it? It happened in my son's new F-150, and besides the extra pint we drained from the fill hole, there's at least that much splashed all over the spare tire and undercarriage.:help:

[Bradley G]

Hey Mike,

The seals are probably cheap.I wouldn't risk banking on Axle seals that have been stressed to the point you describe.If the seals are similar to my old ford truck, the metal spring that wraps the rubber seal is elastic so it may still hold the diff lube but for how long??
Bradley G

P S how did the diff get so overful ? isn't there a hole in the diff at the proper level??Was the vehicle at a severe angle on jacks??

[TripleTransAm]

I assume there's no vent? Or was the vent blocked?

[Mike Poore]

I assume there's no vent? Or was the vent blocked?At the recommendation of one of his buddies, John bought a Shiney Hiney (not from Wes) that's nothing more than a cover (no gear support, or stud cradle) with a dipstick and an "O" ring zig zag seal for his new F-150. He filled the thing following instructions to the full mark on the dipstick, which was, near as we can figure, at least a quart and a half too much, because we drained almost a quart out of the factory fill hole. Never mind how much got pumped out past the seal on his trip to Ohio and back. What a mess!

Which brings us back to the origonal question; is that seal toast? :mad2:

[MarauderMark]

Which brings us back to the origonal question; is that seal toast? :mad2:

Is this a new truck or used and how many miles on it ?


P S how did the diff get so overful ? isn't there a hole in the diff at the proper level??Was the vehicle at a severe angle on jacks??[/QUOTE]


I had the same thing happen to mine when i installed the girdle(limp hand) and when i took it to dennis he knew as soon as it went up on the rack .
apparently there are 2 holes 1 is at the top and the other is in the middle (fill hole).Most people fill it from the top which is to much..

[Mike Poore]

Is this a new truck or used and how many miles on it ?
P S how did the diff get so overful ? isn't there a hole in the diff at the proper level??Was the vehicle at a severe angle on jacks??


It's brand new, Mark. He came back from Kauffman's after seeing Tasha's and bought one just like it. He didn't pay attention to the fill hole, or my advice, said the fancy dip-stick gave him all the info he needed. :mad2:

so... are the seals toast?

[MarauderMark]

It's brand new, Mark. He came back from Kauffman's after seeing Tasha's and bought one just like it. He didn't pay attention to the fill hole, or my advice, said the fancy dip-stick gave him all the info he needed. :mad2:

so... are the seals toast?


Well have to get you and him on video next.lol j/k :P anyways i would keep an eye on it and i may swell back to normal it may not but being that its new i would wait to make sure.but when mine was overfilled it never leaked out of there only from the pinion seal and that was at 20k dennis took out the extra and everything went back to normal.so i would say ur chances or good for full recovery..

[David Morton]

There must be a vent, make sure it isn't clogged.

The fill hole is supposed to be just under the level of the axle tubes so that the only lube that ever gets to the bearings is what "tips" into the tubes on turns, they don't need to be constantly submersed in lube. Hence, the seal is not designed like an engine crankshaft seal, so if it is submerged, it will leak. Restore the lube to the correct level and forget about the seal. It shouldn't leak but make sure the parking brakes are cleaned thoroughly as any oil on the outside of the seal will attract the dust onto the outside of the seal and it will work its way into the seal and wear it out.

[Mike Poore]

There must be a vent, make sure it isn't clogged.

The fill hole is supposed to be just under the level of the axle tubes so that the only lube that ever gets to the bearings is what "tips" into the tubes on turns, they don't need to be constantly submersed in lube. Hence, the seal is not designed like an engine crankshaft seal, so if it is submerged, it will leak. Restore the lube to the correct level and forget about the seal. It shouldn't leak but make sure the parking brakes are cleaned thoroughly as any oil on the outside of the seal will attract the dust onto the outside of the seal and it will work its way into the seal and wear it out.
Thanks David. We drained the excess and took it to the car wash and gave it a super scrub-down. Didn't pay attention to the parking brake, or try it, but we'll make another trip to the car wash, and perhaps, give it a good pre-soak with Simple Green, first, also make sure the parking brake is functioning properly. :o