Unseenone,

I noticed in a different post that you had water issues with your rear differential. Did you ever figure out how the water got in?

It can get in via the axle seals I think. Could also get in via that Open rear breather. Every time the differential cools rapidly air will be sucked down that open tube. It won't be Water it will be in the form of moisture in the air that will condense over time. Maybe after 50k or so miles all that moisture in the air adds up.

Wonder why they don't put a filter on the rear like the front? Seems they were concerned over moisture for the front or they would not have bothered with that fancy new breather cap.

Anyone else have water in the rear diff during a change?

 

I was probably saying all these diffs have issued with rust. I theorize it is due to heating and cooling. I already recommend to customers to change their differential fluid every 30k miles or so to keep the bulk of it flushed out, and extend the life of the diffs as much as possible. Mine were also victims to this issue, I am in TX where moisture is something you wish for, which makes it even more surprising.

The result of the moisture is destructive bearing rust, and pitting. Pictures here.

 

Oh, so no water just oxidation damage.

I had read somewhere that paint was an issue. Like they painted the inside of the differential. That paint flakes off and mixes with the oil and causes damage. So don't always need water for the rust process to take hold.

 

There is a coating that breaks down, as a result of the moisture and rust. I remove it when redoing a diff. The main problem though is the rust on the bearings.

 

I also wondered why LR has a new 21st century differential breather on the front diff and a 19th century design on the rear.

My best guess is to credit Ford.

My theory is that Ford uses LR as their launch platform for new ideas that they wanted to try in a mass production format but understandably would not want to put into a Ford named product. Be it aluminum body panels, our Y type exhaust system, small turbo charged V6 engines etc or small stuff like a breather.

In our case, they would have learned that the initial design of the hydrophobic and oleophobic breather did not work and I suppose we are also testing the new D4 design as well.

You will note that is used the term "uses" above as I still believe Ford is continues to direct the design of all LR vehicles.

You have no doubt seen in your rear view mirror, the Ford Explorer that the Police now seem to be using in place of the Crown Vic.

https://www.google.ca/search?q=polic...w=1344&bih=722

Below is for the Discovery Sport - I guess it looks a bit different - the paint I suppose.

http://www.disco3.co.uk/gallery/albu...als_AVS_15.pdf

 

Hi found this bit of information while searching for something else, hope it helps,

A smaller pipe, which is not associated with the fuel system, is attached to the side of the fuel filler pipe. This pipe connects to the rear differential and provides breathing for the differential case. The pipe terminates near the fuel filler head.