So I did my big 15k LOF job yesterday. Transmission drain/fill, Transfer drain/fill, engine oil/filter drain/fill, and, crucially, differential drain/fill.
I already have strong suspicions here, but here’s what came out of my front diff. Looks like Birfield soup to me. Annoyingly, I did the Big Axle Job 11k miles ago, so the seals didn’t last very long at all (I didn’t actually HAVE to drain and fill the front diff, but I did anyway, and I’m glad I caught it 4k miles early).
I suspect, among the million other ways the axle seal could fail, that my diff breather was clogged. One, it looks like crap, and was obviously sneezing out greasy BS for a while. Two, I had a significant vacuum pop when I pulled the fill plug, indicating that the diff was generating a good vacuum pull that could have sucked moly past the seals. I have no drips from my Birfs, so for now, it looks like the leak has been one-way.
Although the axle seals will have to be dealt with, my short term band-aid was to replace and extend the diff breather line, if for no other reason than to help with the vacuum issue.
Just adding to the 80 Series Tech forum so others can see the issue in case they get the same thing, and of course I welcome y’all weighing in.
edit: grr, can’t attach the video of the Birfield soup concoction draining from the diff. I’ll try another way in a minute
I already have strong suspicions here, but here’s what came out of my front diff. Looks like Birfield soup to me. Annoyingly, I did the Big Axle Job 11k miles ago, so the seals didn’t last very long at all (I didn’t actually HAVE to drain and fill the front diff, but I did anyway, and I’m glad I caught it 4k miles early).
I suspect, among the million other ways the axle seal could fail, that my diff breather was clogged. One, it looks like crap, and was obviously sneezing out greasy BS for a while. Two, I had a significant vacuum pop when I pulled the fill plug, indicating that the diff was generating a good vacuum pull that could have sucked moly past the seals. I have no drips from my Birfs, so for now, it looks like the leak has been one-way.
Although the axle seals will have to be dealt with, my short term band-aid was to replace and extend the diff breather line, if for no other reason than to help with the vacuum issue.
Just adding to the 80 Series Tech forum so others can see the issue in case they get the same thing, and of course I welcome y’all weighing in.
edit: grr, can’t attach the video of the Birfield soup concoction draining from the diff. I’ll try another way in a minute
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