Well, here we disagree. If the tube is plugged, then there is no air flow in and out of the diff tube, hence no scourse of moisture to in the air to condense.
Bottom line, if the tube is plugged, then it is plugged and water seepage into the vent tube is really the only way to turn the gear oil to milk.

 

Fair enough Mike, fair enough.

 

Seems like you both might have a point. I think that theTSB was for water entering the vent tube (not only just from deep water though). Having a clogged vent would only make it worse. No doubt a leaky pinion seal would let water in too, if fluid can come out - there's a lot of road spray right there.

 

I would say pinion seal and clogged vent tube. You run through water and the diff cools down and sucks water in through the seal. Happened to me. I don't suggest running with water for very long, but I will tell you that I went to a powerboat race where they race to a bouy and round it and come back. The guy we were sponsoring cracked his outdrive and flooded it with seawater at the turn. He made it back fine (won the race and set a record), and after inspecting the parts, did no damage to the internals. He was running RP. Again, I am not saying to flood your diffs with seawater, but you can feel a little more confident about putting RP in.

 

Wow, you can always tell who the saleman is. LOL

(I'm one too)

 

I have a 2007 Range Rover Supercharged and recently drove it thru a flooded street and immeditely after getting out of the water it started making a noise from the passenger rear. The dealership said it was the rear differential but my insurance adjuster is saying water can not get in the rear differential so it was not the cause of it going out. Is this completely true or can water get in there from driving thru a flood? I just can't believe it was that big of a coincidence that the rear differential went bad on it's on immeditely after driving thru the water.

 

Well I'm not going to begin to explain how wrong this forum/category/thread is for your questions, but I will say that your diff is not going to go bad even remotely close in time to the water entering it.

We have solid axles, which means that the differential goes into the axle housing and the oil can go all the way through the axle housing. You have independent suspension, so your diff is a small unit in the rear center of your vehicle, where it is much higher up than ours. By design water should not be able to get into your differential, but it's not as though any differential design allows for water ingress, seals just get old and it allows water in.

 

I had an '06 Rangie Supercharged (full size) rear diff had to be replaced at 51,000 miles. No water crossings, ever. Bearings were humming like a sum bitch. No explanation.

 

LR3s had that same issue.

 

There are many after market wading kits for differentials which help keep water out when driving in deep rivers, gullies etc.

http://www.rovacraft.com.au/products..._equipment.pdf