MAINTENANCE : Jeep JK Wrangler Differential Fluid Change Write-Up

Mr.T

New member
Quick question...I unscrewed the filler plug on my 2012 jk rubicon and fluid came gushing out ? I'm guessing .25 quarts on the ground. How the heck would they get fluid that far over the filler plug and now do I need to drain and refill to make sure the correct amount is in there? Also the 2012 manual says 80w 90 oil, is 75w 90 alright to use. Thanks

It can get overfilled by adding oil with the Jeep on a slant, worst case is that some water got in and raised the level.

Regarding the 75w, the number before the w is the "winter", or cold viscosity. I can't remember the details, but it means the oil actually has the viscosity of a traditional 75 grade gear oil at some specified cold temperature in a standard test. The 90 number represents the viscosity at some standard normal operating temp. Bottom line is that 90 is the most important number, and 75w means it isn't as thick as an 80w in the cold. A number higher than 80w would be undesirable, but lower is better as long as other oil qualities aren't compromised in the process. I use a 75w/90 synthetic in everything that calls for 80w/90.

:beer:
 

Criztaztrophe

New member
so what should you do if you discover it looks like this?
:yawn37:
rear dif.jpg

I KNOW ... Take the cover off, new gasket, and some royal purple!! Looks like I have one more thing to add to my list of need to do's! lol
 
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bl17z90

New member
Hey Eddie, can you use synthetic in a non limited slip? I was thiniking about just going all synthetic if my Jeep can use it.
 

BlackKnight

Member
After the 1500 mile break in period (sometime in the next 2-3 weeks, already at 600 after a week) I'm changing every fluid to RP synthetic. Researching all the fluid types/amounts for the change, along with the best filters. the hardest part will be the auto trans :(. I'm debating pulling the pan to replace out the filter as well. It shouldn't of course need it, but I'm thinking about it..
 

bl17z90

New member
Sure you can. No reason why not.

Ok I was just curious because the stickers on my axles are unreadable now so without calling Chrysler (i really hate dealing with them) I don't know for sure what kind of differential I have. So if I can use synthetic on it anyways just to be safe thats great.
 

wayoflife

Administrator
Staff member
Ok I was just curious because the stickers on my axles are unreadable now so without calling Chrysler (i really hate dealing with them) I don't know for sure what kind of differential I have. So if I can use synthetic on it anyways just to be safe thats great.

I seriously doubt that you have limited slip but, if you do, synth gear oil will have you covered. If not, no big deal. You'll be just fine.
 

geman

New member
Hey Eddie, probably im being redundant but dont wanna screw it up. I have a 09 rubi with lockers, i only need the synthetic oil? no additive right? thanks!
 

DJKU09

New member
I got 75-140 gear oil. Its that ok? I got an 09 jk wrangler unlimited. 3.73 gears

I love bacon
 

mallaki

Member
I have 2012 JKU Sport with 35" and I live in NYC… I had my gears changed from 3.21 to 4.88... Originally after gears were changed, a heavier fluid was used (I could see it on my next change).

After the 500 mile break-in period I used the OEM Mopar 80W-90...

Now it’s time for another fluid change, my question is , should I go again with Mopar (or any other brand) 80W-90 as Chrysler recommends –(but please keep in mind they only recommend this for gears 3.21 to 4.10) or should I use something heavier?

As I mentioned before, I live in New York City, where it gets cold in winter and hot in summer… and I do as much as I can off-roading (few times a year)

So, 2012 JKU…4.88 gears… 80W-90 or heavier?

---Peter
 
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I have 2012 JKU Sport with 35" and I live in NYC… I had my gears changed from 3.21 to 4.88... Originally after gears were changed, a heavier fluid was used (I could see it on my next change).

After the 500 mile break-in period I used the OEM Mopar 80W-90...

Now it’s time for another fluid change, my question is , should I go again with Mopar (or any other brand) 80W-90 as Chrysler recommends –(but please keep in mind they only recommend this for gears 3.21 to 4.10) or should I use something heavier?

As I mentioned before, I live in New York City, where it gets cold in winter and hot in summer… and I do as much as I can off-roading (few times a year)

So, 2012 JKU…4.88 gears… 80W-90 or heavier?

---Peter

Peter,

I went to Napa Auto Parts and picked up the fluid type Eddie mentioned in his write up. Also went with a synthetic instead of Dino oil. I have about 1500 miles on my change.

R/
Will


Sent from my fRuit product using WAL
 

mallaki

Member
Peter,

I went to Napa Auto Parts and picked up the fluid type Eddie mentioned in his write up. Also went with a synthetic instead of Dino oil. I have about 1500 miles on my change.

R/
Will


Sent from my fRuit product using WAL

Right, but I think Eddie might have recommend 75W-90 for stock gears -3.21 to 4.10… My question/concern is having these lower gears (4.88) wouldn’t I benefit from heavier lubricant? Or even wouldn’t be wise to use heavier lubricant running 4.88 gears?

Thanks again,
---Peter
 

JoseRubicon

New member
Anyone know the torque the Dana 44 covers should be torqued at when changing fluid? I did my change and it's leaking. I think I

1) didn't let the right stuff dry and put on right away

2) might have put on the cover too toght and squeeze the rtv out.

The bolts where so hard to take off! But I think it was the paint...
 

OverlanderJK

Resident Smartass
Anyone know the torque the Dana 44 covers should be torqued at when changing fluid? I did my change and it's leaking. I think I

1) didn't let the right stuff dry and put on right away

2) might have put on the cover too toght and squeeze the rtv out.

The bolts where so hard to take off! But I think it was the paint...

You probably didn't use enough RTV. Your supposed to tighten them and then wait an hour or more and retorque.
 

Mr.T

New member
If there was a drop of oil on the mating surface, that can keep the RTV from adhering as well. Guestimate that 20 ft-lbs is about right.

:beer:
 
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