Rear axle fluid is milky all the time
I changed the rear diff fluid a couple of weeks ago on a scheduled basis. I was stunned by its color. It was something between the "coffee-and-milk", an old oil from the fryer and - sorry - children's diarrhea. Everything inside the diff housing was covered with reddish scurf but details were not rusty. I just wiped them off with a piece of cloth and they became shiny again.
I continue... Along with the "oil" I found some unidentified pieces of black rubber (???) inside the diff's housing. I decided it was the sealant's excess but I never seen the stuff inside the diff before.
My first thought was I somehow killed the vari-lock and the "oil" looks so strange due to worn clutch inside of varilok. But I didn't check that. Just removed the gunk and changed the oil.
It has been 2 weeks from the oil change. The truck passed ~500km, no off-road, no fords, nothing. Today I pulled the plug out of the differential cover and what do you think? I can see almost the same milky "oil" inside the diff (well, maybe not so milky as the previous time...). The diff's breather is ok, oil seals are ok too, so I don't think it's water.
What else it might be if not the water? Should I buy new varilok - 52104674AE? Or change the make of my oil (which is Castrol Syntrax Limited Slip 75W-140)
Any feedback would be highly appreciated.
Last edited by AByrvalg; 08-10-2013 at 01:18 PM.