Need Help! Im so confused.

[Redman1911]

Thanks. Will do. Here is something strange. I had to help my brother last week. He bough a parts truck for his Bronco....Long story short I towed the f150 with my Expedition and it did fine. Whats strange is for about a week after that problem went away now its starting to come back. Really weird.

 

[03 exp]

Plus one on friction modifier fixed mine!

 

[Redman1911]

Well this may not matter but I checked my differential and it's full. Should I just drain it and get some motorcraft 70w-140 synthetic