I have a Ford F150 3.5 ecoboost XL FX4 and am wondering if I need to worry about the barings and the seals. Took in my truck for front, rear and transfer case fluid change and they found a small amount of water in the fluid (rear). The mechanic said the seals allow water to get in but does not allow fluid to get out. No fluid has leaked out and no damage inside the differential. No play in the axle.
A mechanic friend of mine says water got in the seals and barring need to be replaced or water could have got into the vent.
What do you experts think?
I would have got water into the differential likely from driving through a low water crossing (creek crossing).