Water in the Rear Differential


New member
I’m upgrading my diff covers to ARBs and this is what I found in my rear axle. 2015 JKUR.

I don’t see any signs of damage on the ring or the portion of the pinion I can see, and there isn’t a pile of metal shards at the bottom of the housing. The chunks you see are RTV I scraped off.

Is there anything specific I should inspect for or be wary of? The stock elockers engage and I haven’t had any problems with the Jeep.

I bought this from a dealer in Texas in Nov, but their paperwork doesn’t say anything about changing the diff fluid. I did submerge it a few weeks ago in a big old mud puddle so I’m guessing it’s connected and I should be prepared to change the diff oil when I let the redneck side come out. The front looked like a darker oil and not a latte

Any thoughts?


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New member
Replace the oil, and run a higher diff breather?

I made sure the breather tube is attached to the axle and it’s tucked into the frame above the exhaust. The good thing is it’s pretty easy for me to avoid large bodies of water in my day to day life

I saw a video last night of a guy with similar looking diff fluid (can we call it “oil” at this point?) and he changed his oil 4x over a few hundred miles. The tubes can collect water and grime, so it looks like the best thing to do is disassemble the rear axle, scrub it, replace the seals, and relocate the breather tube into the tub behind the tail light assembly.

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If it Isn't leaking oil out the axle tubes, then its well sealed and water shouldn't be able to get in either. The only other area water should be able to get in is the breather hose. A 2-3ft. extension is cheap insurance that you don't accidentally get water in and forget or don't realize it. Id run the end of the breather up above the top level of the tire. Plus avoiding water is no fun :)

I wouldnt bother dissasembling it, just spray it down with a can or 2 of Brakeclean. Any small amount of moisture thats still in it should evap. out after a few drives. Just changing the oil is 95% of the issue.


I piss excellence.
That definitely looks like water got in the oil to me too. I would put some cheap oil in it, run it down the road and get it warm then come back and drain it to see what it looks like. You don't want that much water staying in. Also check your other axle, transmission and transfer case if you haven't already.