Any time your are sealing Gear Oil you need to use this product. Its designed to be used for Differentials and Transfer Cases. Your standard Gasket Maker will not work with Gear Oil.
Permatex Gear Oil RTV gasket maker is specially formulated to withstand the friction modifiers in conventional and synthetic gear oils that breakdown normal RTV's and cause leaks. This specialty silicone has been tested to OEM specifications to ensure complete sealing of differentials and transfer cases. Can be used as a gasket maker or a cut gasket sealant.