Hey Wagnum, sorry and kinda of relieved that you ran into the same issue. I found the same info on the solid axle AMCbut was hoping I could avoid having to make any sort of drain or channel. Had the same results with ARB, no help to date. I haven't made any changes to the diff yet. What I have done is run a new vent live for the trans and t-case to the air box to avoid any future cross contamination. I also moved the rear diff vent line to an empty plastic water bottle, I know big time red neck fix... I put a quick connect vent filter on the end to provide some resistance. I put a whole just large enough for the vent line in the bottle cap and hung the bottle upside down in the rear passengers wheel well. When it accumulates fluid I drain it out. I have noticed that when I park after driving for a good amount of pressure, air and a bit of fluid, can be heard blowing into the bottle. I also found that my rear portals were both FULL! Also had one front that was high, that might be from the front diff as that is ARB Also. My rear diff is now making a clucking noise so I have to drop it out again and take a look. Not sure if the pressure buildup is causing the diff to partially lock or what. Will let you know. I have also pulled the cover and changed the fluid and all looked good...
I also swapped both axles out for a new pair. Did find an outer that was bone dry and the boots were pretty dry rotted. I used axles from parts-liquidator on ebay, they use junk boots that leak... I ended up having to replace all the boots to get the grease to stop leaking out. They did refund me some money but was not worth the amount I saved. Especially since I torn my bicep tendon during one of the replacements.
