Haven't used the forum in a while, but my truck has 112,000 miles on her now and I've been considering changing the differential fluid. I've searched and found a ton of different opinions. I have 3.55 gears and a non limited slip and the tag says to use 75w140. However, I''ve heard Ford now recommends 75w90 because it can absorb water. I've also heard that the fluid shouldn't really ever need to be replaced. It currently runs fine, I never tow any anything. Truck is my daily driver. Would appreciate some clarity on what to try. Thanks !