Rear diff oil black?

[NovaJeep]

I just changed my gear oil on both diffs (rear Dana 44 LSD) at 7900 km. The front was golden honey colour, the rear was a dark black-purple. There were some metal filings in the magnet, but nothing that seemed overly concerning. The rear may have had some water through the breather, but it didn't look to have water content in it from brief inspection. In the photo, the cap was wiped off and then re-dipped in the draining oil about halfway through, so this colour was very consistent throughout the whole diff.

My dealer recomended 80W-90 front and 75W-140 rear (for towing and/ or offroading, otherwise 80W-90 rear is also acceptable). My manual calls for SAE 75W85 (API GL-5), but my dealer tells me there was an update to the differential fluids.

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[NovaJeep]

Stock JLU Sahara, 12XXX KM's, 90% highway.

Was getting an oil change and the mechanic was saying my rear diff oil looks really black, and to get it checked by the dealership but could also just be the color of the oil jeeps are using for the JLs... Can anyone put some insight on this? I am going in a few days because they are ordering a new steering stabalizer due to it having the death wobble...

Sorry to bump an old thread, but any news from the dealer when you brought it in?

I've changed my oil twice total (currently at 18000 km) and each time it comes out dark grey/ black. I used royal purple last time, which went in a dark purple, may be a contributing factor this time around - not sure.

 

[Arterius2]

Sorry to bump an old thread, but any news from the dealer when you brought it in?

I've changed my oil twice total (currently at 18000 km) and each time it comes out dark grey/ black. I used royal purple last time, which went in a dark purple, may be a contributing factor this time around - not sure.

Same, do you have limited slip? Mine came out that way as well, colour seems to be pretty normal for LSDs with friction modifiers additive.

 

[Bearded_Dragon]

Same, do you have limited slip? Mine came out that way as well, colour seems to be pretty normal for LSDs with friction modifiers additive.

I changed both front and rear at 8000 miles and they were black. This is in a Rubicon so no LSD.

 

[NovaJeep]

Same, do you have limited slip? Mine came out that way as well, colour seems to be pretty normal for LSDs with friction modifiers additive.

I do have a LSD, which explains why it's my rear only that's black (I should have clarified that). Thanks for letting me know, eases my mind quite a bit!

 

[rustyshakelford]

What’s the reason y’all are changing your oil so frequently? Deep water crossing regularly or just aggressive preventive maintenance?

Brett

 

[intentsrig]

Black is normal after wear and use. Just change it.

Mine was actually super black after only 1k miles or so. Turns out my LSD clutch packs were basically disintegrating!

 

[BlackJL]

Stock JLU Sahara, 12XXX KM's, 90% highway.

Was getting an oil change and the mechanic was saying my rear diff oil looks really black, and to get it checked by the dealership but could also just be the color of the oil jeeps are using for the JLs... Can anyone put some insight on this? I am going in a few days because they are ordering a new steering stabalizer due to it having the death wobble...

I just took my 2018 Wrangler JLU that I bought last November into https://oilchangers.com/ for an oil change. Same issue. As part of the service they check the differentials and transfer case. Rear diff was black and he recommended to have it changed. I told him i would get back to him after some research because I didn't think that my JLU with only 12,000 miles should have black diff oil yet. 90% highway and only went 4 wheeling once. I think I will take it to the dealer as well but I am open to suggestions from this forum. Cheers.

 

[Lou_JLU]

I just took my 2018 Wrangler JLU that I bought last November into https://oilchangers.com/ for an oil change. Same issue. As part of the service they check the differentials and transfer case. Rear diff was black and he recommended to have it changed. I told him i would get back to him after some research because I didn't think that my JLU with only 12,000 miles should have black diff oil yet. 90% highway and only went 4 wheeling once. I think I will take it to the dealer as well but I am open to suggestions from this forum. Cheers.

From your description you probably have the Dana 44 (M220) with "Anti-Spin" LSD? got a lift installed? If so reference the tread below it may be of interest to you. BTW you might want to start having your radio off when you are coasting/decelerating in the 30 to 5 MPH range. This is where some of us have experienced some rotational clunking/knocking.

https://www.jlwranglerforums.com/forum/threads/knock-in-rear-with-dana-44.16921/

Regards,

 

[CarbonSteel]

For information, the vast majority of axle wear occurs at less than 15K miles and so it would not be a surprise to see really dark oil on a change around that mileage.

UOAs will show a lot of metal in a sample around 15K, but with longer and longer subsequent runs, the wear metals will continue to drop.

 

[BlackJL]

From your description you probably have the Dana 44 (M220) with "Anti-Spin" LSD? got a lift installed? If so reference the tread below it may be of interest to you. BTW you might want to start having your radio off when you are coasting/decelerating in the 30 to 5 MPH range. This is where some of us have experienced some rotational clunking/knocking.

https://www.jlwranglerforums.com/forum/threads/knock-in-rear-with-dana-44.16921/

Regards,

Sorry for the late reply, thank you very much. I don't have a lift but should get it back from the dealership shop today so we will see what they say.

 

[BlackJL]

****UPDATE****
Just got my JLU back from the dealership after a complete rebuild of the rear diff. We will see how she holds. I will keep everyone informed. Happy Jeepin!

 

[Lou_JLU]

****UPDATE****
Just got my JLU back from the dealership after a complete rebuild of the rear diff. We will see how she holds. I will keep everyone informed. Happy Jeepin!

Nicely detailed and documented repair description by the dealership. Not often seen... they're a keeper.

 

[rockadile]

Rubicon’s with the trailer tow package have 75/140 synthetic gear oil factory.
Rubicon’s without the trailer tow package have 85/90 conventional hypoid gear oil factory.

How do you know this? In the manual, there is no mention of this for the M220. It simply states:

We recommend you use Mopar Gear & Axle Lubricant (SAE 75W85)(API GL-5). Models equipped with Trac-Lok Limited Slip Differential require a friction modifier additive.

 

[CarbonSteel]

How do you know this? In the manual, there is no mention of this for the M220. It simply states:

I can confirm that although my Rubicon has the towing package, it DID NOT have 75W-140 in the rear axle from the factory. It had 75W-85/80W-90 in it just like the front axle.

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