Changing differential and transfer case oil after deep water crossing.
So after having to ford through some deep water (36-38") I decided that I must've gotten water where it shouldn't be, as there was about 2-3" of water in the cab after finishing the river crossing. There would've been a lot more inside if I had stopped. Point is, water got in some of the breather tubes. I would've changed fluids right then, but this was WAY backwoods. I had to drive 60 miles back home. I didn't think there was a big problem until doing some reading. I planned to change fluids when I had a day off. I noticed a vibration the other day when on the throttle at all; it disappears when I let the truck coast. All fluids must get changed!
Upon draining the transfer case, the fluid looked like a strawberry milkshake. Milky pink, with chunks (water droplets). Lots of emulsified water in there. I drained it all out, and put in new Dextron ATF fluid, as per Ford's specs. I went for a drive to get the differential oil warm again, and still have the vibration.
I just drained the rear case, which was nasty opaque sludge, but no apparent water. I did notice a bit of rust on one side of the gears, but the truck has 399,000 mi on the odometer. it's not a new truck. There's no way the rust is new. The vibration is. There is however a fair bit of wear apparent in the gears. Will post pics later.
I loosened the tranny drain plug, and got perfectly clear, like-new ATF fluid out of it. I don't even know if it has a breather tube or not , but I'm just going to top it off. There is no sign of any water at all, and it was rebuilt last summer anyway.
I can't figure out how to drain the front differential. WTF!! I have no idea what axle it is, other than that it's a 3.55 ratio. Do some have no drain plug? There's a big fill plug about halfway up, but I can't find a drain, and there's no rear cover to remove. It seems to be two, very thick halves, but the front side, where the bolts are, is connected to the steering arm, which would be a ***** to remove to say the least. Can I just shove a tube down there and use a vacuum pump to pull it out?