I am wondering what is needed to refill a rear dif in a 2002 FX4 with the 9.75 rear-end. I read about friction modifier and synthetic fluids. Whew....I was on overload. What is the best to put back in? I have a slight leak from the rear dif cover. I am going to replace that cover with an aluminum girdle. I am also going to use the RTV sealer for my gasket. Any tips or tricks would be much appreciated.

 

regular dinosaur oil is better for your factory limited slip . . synthetic wears our the clutches, hence why many people in the community think the factory limited slip sucks.

i believe youll need around two an a half quarts and the friction modifier, dont quote me i cant put my finger on the exact amount, but fluid will flow out the fill hole if you are overfilling (the holes in the side not on top)

good choice of aluminum girdle and RTV for your gasket is spot on. just be very careful on your torque, i believe 12-15 footpounds is spec