Differential overfull?

[Huskerbob]

Checking some things this morning and found the rear differential was overfull. Pulled the fill plug and quite a bit of gear oil came out. First what damage could have been done by an overfull diff and second how the heck did it get above the fill hole in the first place. Checked it on level ground and the vehicle was not jacked up. What should I be looking for or should I just let that sleeping dog lie?

2003 4x4 6 cyl.

 

[EXPLORER04]

The rear diff was not overfilled. The correct way to service the rear diff is to fill to the bottom of the fill plug, replace the plug and then add an additional one pint through the ABS sensor mounted on the top of the diff.

 

[Exproblems]

The correct way to service the rear diff is to fill to the bottom of the drain plug, .

Fill the diff to the bottom of the large "drain" plug or fill it up to the bottom of the higher up, smaller "fill" plug, before adding another pint thru the top at the ABS sensor?

 

[EXPLORER04]

my mistake, i meant the fill plug

 

[Huskerbob]

The rear diff was not overfilled. The correct way to service the rear diff is to fill to the bottom of the fill plug, replace the plug and then add an additional one pint through the ABS sensor mounted on the top of the diff.

So I need to add back the stuff that drained out? I might as well go ahead and drain and change it all then. It was pretty ugly looking oil. Thanks.

 

[Huskerbob]

differential fill question?

The rear diff was not overfilled. The correct way to service the rear diff is to fill to the bottom of the fill plug, replace the plug and then add an additional one pint through the ABS sensor mounted on the top of the diff.

Okay, so I took the spare tire out and jacked her up and I can just barely see the ABS sensor on the front driver side of the diffy with a mirror. I can see NO way to get at it. I can't even touch it. Any ideas?

 

[swshawaii]

Not critical. Add 4 ounces of XL-3 friction modifier BEFORE filling with 75W-140. BTW, is your axle vent tube plugged up?

 

[Huskerbob]

Not critical. Add 4 ounces of XL-3 friction modifier BEFORE filling with 75W-140. BTW, is your axle vent tube plugged up?

No, the vent tube is clear. Thanks for the added information. I will follow your instructions. Aloha

 

[unclemeat]

So I need to add back the stuff that drained out? I might as well go ahead and drain and change it all then. I was pretty ugly looking oil. Thanks.

Could that extra volume be from water getting in the diff?

Was the oil like chocolate milk?

 

[Huskerbob]

Could that extra volume be from water getting in the diff?

Was the oil like chocolate milk?

Well, when I first went to check the level quit a bit of it ran out and landed on my garage floor and on me.

Pretty much pure gear oil with no visible water. So I'm guessing it was just that factory fill. I am replacing it tomorrow with the friction modifier suggested by swshawaii.

On the plus side my 3/8" ratchet is well lubricated now. (and soon I will be as well

 

[Exproblems]

Well, when I first went to check the level quit a bit of it ran out and landed on my garage floor and on me.


:

Nothing like "grease monkey cologne"!

 

[Huskerbob]

Nothing like "grease monkey cologne"!

Gosh darnit! I love the smell of gear oil in the morning!

 

[roush9799]

I never understood why they add the pint above the fill hole, why didn't they just make the fill hole a little higher up? Any time you check it you're gonna lose the extra.

 

[Huskerbob]

I never understood why they add the pint above the fill hole, why didn't they just make the fill hole a little higher up? Any time you check it you're gonna lose the extra.

Good question. Must be to piss us shade tree mechanics off. If so, it's working

 

[Ronin8002]

It must be a newer modified procedure, because in my shop manuals for my 2004 and 2008 they specify to fill it to the bottom edge of the fill hole. I don't know how you'd fill it up more than that on a 2005 or later with Advancetrac since none of those have an ABS sensor on the diff. Maybe they thought that having more gear oil in it would prevent the rear diff whine?

 

[Huskerbob]

It must be a newer modified procedure, because in my shop manuals for my 2004 and 2008 they specify to fill it to the bottom edge of the fill hole. I don't know how you'd fill it up more than that on a 2005 or later with Advancetrac since none of those have an ABS sensor on the diff. Maybe they thought that having more gear oil in it would prevent the rear diff whine?

Actually it seems quieter since I drained out the pint. The whine was the reason I looked in the first place. My shop manual says the same as yours, fill to bottom of the upper hole. Friction modifier and a clean fill should do it.

Oh well, what is you gonna do?

 

[EXPLORER04]

Actually it seems quieter since I drained out the pint. The whine was the reason I looked in the first place. My shop manual says the same as yours, fill to bottom of the upper hole. Friction modifier and a clean fill should do it.

Oh well, what is you gonna do?

What manual do you use?

 

[Huskerbob]

What manual do you use?

Chilton 2002-2003 Ford Exploder

 

[Ronin8002]

I use the 10 pound, 2 volume, ford factory service manual for my 2008. I had a similar one for my 2004 before selling it, but both checked out against the alldatadiy.com site as far as the diff refill procedure goes. I just wonder if the extra pint thing is part of a TSB or something.

 

[Huskerbob]

I use the 10 pound, 2 volume, ford factory service manual for my 2008. I had a similar one for my 2004 before selling it, but both checked out against the alldatadiy.com site as far as the diff refill procedure goes. I just wonder if the extra pint thing is part of a TSB or something.

I'm not sure but I do know that there is no way in hell, without dropping the axle, to get at that ABS gizzo so I'm thinking it's that way from the factory. Anyway what I'm going to do is add the 4 ozs of friction modifier and top it off with 75/90 goo.