This time, front diff oil was dirty

[NWJeepr]

'23 Rubi XR with the wide axles. I did the first differential service at 2k miles following a trip to Moab. The rear was dirty, but the front was basically fresh. Filled both with 75-140. Did another trip to Moab, and dumped the diffs again this weekend at 5,600 miles. Rear was mostly clean, but front was dirty.

I wish I had saved a pic but fumbling for a phone in the moment would have been messy. Any theories as to why the front would be so much darker than the rear? No water crossings ever, so far.

Two diff services in <6k miles is probably too much, but the limited oil capacity and a couple of extreme-use cases in those miles had me curious how the oil would hold up.

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[Kracka]

I noticed the same on my wife's MY23 Rubicon. I replaced the differential fluids at 1500, 17k, & 22k miles. The rear was darkest at 1500 while the front was darkest at 17k. Both were clean at 22k and that fluid remains clean now at 25k (aFe differential covers with sight glasses).

My theory is that the rear works harder so it breaks in my quickly and it takes the front longer to full break-in being under less stress. I think a few early changes is ideal to get that break-in debris out.

Like you, we've used 4WD, 4Lo, & lockers during all intervals thus far.

As info, I run Redline 75W-85 GL-5 gear oil in the differentials and Redline C+ ATF in the [transfer case.