Technical Notes: Yukon recommends the use of high grade GL-5 gear oil and two bottles of Yukon LSD (Limited Slip Differential) additive for long life and smooth operation. Part number OILADD. The use of synthetic oil is allowed but may result in aggressive or noisy operation.
F150 2011-2018 that have Only Ford 9.75" rear ends.
CALIFORNIA RESIDENTS: PROP 65