Greetings.

I just bought a 2006 F-150 4X4 with a 3.55 limited slip rear and 98,000 miles. I doubt that the differentials have been serviced. Do the clutches etc in the rear diff need to be checked and adjusted, or is it simply a matter of changing the gear oil and friction modifier?

Thanks in advance.

 

Just change the fluid.

75W140 full synthetic and a bottle of XL-3 friction modifier from Ford.

 

Thanks.