2010 Mountaineer differential full of water

[wdbates]

At 22,000 miles I noticed that the differential was leaking at the pinion seal. When replacing the seal it was discovered that the differential was overflowing with water, pass the fill plug. Now 90,000 miles later the differential is making a whining noise and when the mechanic open the fill plug (checking the oil level) he was covered with oil and water.

This is my wife's grocery getter and spends most of its time in an enclosed garage. We don't have a boat so its never been down a boat ramp. Most of the driving is on the interstate between our house and her mothers, about 20 miles. Never in flood conditions.

What gives? This is the AWD version with V8. Does the vent plug have a check valve or is it open?

One more thing, this was service by a Ford, Lincoln dealership using the Mountaineer's maintenance schedule.

 

[Explorer_PL]

Is the vent tube intact ?

 

[wdbates]

Is the vent tube intact ?

Never seen a tube like on the front differential. Looking at the parts online the only vent for the rear differential is Vent Assy - Rear Axle Part #: 4022.

 

[michael loibl]

I’ve been meaning to change my front and rear pumpkin fluids for a few months now, Maybe one night next week I’ll put it on the lift at work and do it and check to see what kind of a breather I have on the front and rear