Permatex Gear Oil RTV Gasket Maker is specially formulated to withstand the harsh gear oil environment found in differentials and transfer cases. Gear oil has friction modifiers that break down normal RTV and cause leaking, but this specialty silicone has been tested to Original Equipment Manufacturer (OEM) specifications to ensure complete sealing power. As a gasket maker it seeks and seals leak paths that cut gaskets cannot. Suggested applications: differentials and transfer cases.