Diff fluid all over underside of hood

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BradD

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I have a problem with my 2004 rubicon I’m unable to figure out. I recently changed my front diff cover to an ARB one. The mechanic said he put in 2qts.

I mostly drive around town. The last 4 trips on the highway when it really heats up I start smelling gear oil. When I pop the hood up by the drivers side front it has fluid all over the underside of the hood and all down the front left of the jeep engine compartment. I first thought it was a high pressure power steering hose leak and I changed it out.

It’s still doing it and I believe is the breather hose from the diff. I checked the dipstick on the diff cover and it has no markings but it doesn’t appear to be much of anything on the dipstick. Why would switching the cover be blowing all my fluid out of the hose?
 
It's probably over-filled. The classic symptom of a diff that's over-filled is oil blowing out the breather tube. It will find its happy level by doing that. It's messy, but once it's blown out what it needs to blow out, it'll be good to go.
 
sab said:
It's probably over-filled. The classic symptom of a diff that's over-filled is oil blowing out the breather tube. It will find its happy level by doing that. It's messy, but once it's blown out what it needs to blow out, it'll be good to go.
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That was my thought but when I didn’t really see any on the dipstick I started second guessing myself. Thought maybe the air from the lockers was blowing it out, but that’s way more advanced than my knowledge base.
 
I don't know much about the ARB covers and their dipstick. Maybe someone with one of them will give their thoughts. As for whether the air locker is leaking enough to blow oil out, I would think that could be tested in your driveway. Lock the locker and listen/look for oil/air hissing out the breather.
 
BradD said:
.... The mechanic said he put in 2qts.

...
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He over filled the front. FSM states 1.375qts. Anything not stock in components or orientation is going to change that volume one way or the other.

The diff is going to slowly spit the extra fluid it doesn't want up and out through the breather hose. Eventually it will stop when the fluid volume reaches stasis with it's container.
 
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BradD said:
I checked the dipstick on the diff cover and it has no markings but it doesn’t appear to be much of anything on the dipstick.
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1. Drain the remaining diff fluid.

2. Fill back with 1.375 qts.

3. Insert dipstick to find appropriate fluid level.

4. Use knife to mark appropriate level on dipstick.
 
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BradD said:
.Why would switching the cover be blowing all my fluid out of the hose?
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Your aftermarket cover probably has a higher fill port for diffs that are leaning back (after a lift and usually in the rear).
You should fill till the level is up to the bottom of the axle shafts. That's where the factory fill hole is on a stock jeep.
YRMV
 
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FWIW:
ee.jpg

How I marked the dipstick when I installed an ARB cover on my Dana 35.
 
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jjvw said:
FSM states 1.375qts.
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I had 1.375 qts in my notes for my 2005 Rubicon, but when I go back and look in the 2003-2006 manuals, they all state 4.0 pts (2 qts) in the section on fluid capacities. For instance, this is from page 0-7 of the 2004 FSM, but all the manuals state the same capacity (4.0 pts) for a front Dana 44:

1715262959235.png


Is there some other reference, or some other section of the FSM, where the capacity is noted to be 1.375 qt?
 
sab said:
I had 1.375 qts in my notes for my 2005 Rubicon, but when I go back and look in the 2003-2006 manuals, they all state 4.0 pts (2 qts) in the section on fluid capacities. For instance, this is from page 0-7 of the 2004 FSM, but all the manuals state the same capacity (4.0 pts) for a front Dana 44:

View attachment 525440

Is there some other reference, or some other section of the FSM, where the capacity is noted to be 1.375 qt?
Click to expand...

Nearly certain my 2003 FSM states 1.375 front, 2 rear. And I also recall there being a discrepancy between years.

What I do know is that the front does not have axle tubes to partly fill with oil.

Either way, when the diffs are overfilled, they will self correct. Mine are no longer anything stock other than the housing. I still add the factory specified volumes and both will spit for a few weeks until settled.
 
jjvw said:
He over filled the front. FSM states 1.375qts. Anything not stock in components or orientation is going to change that volume one way or the other.

The diff is going to slowly spit the extra fluid it doesn't want up and out through the breather hose. Eventually it will stop when the fluid volume reaches stasis with it's container.
Click to expand...

Thanks, guess I missed that he told me they were 2qts and I took him for his word.
 
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