Permatex Gear Oil RTV Gasket Maker is a specialty gasket maker that is specially formulated to withstand the harsh gear oil environment found in differentials and transfer cases, ensuring a leak-proof seal. Because gear oil has friction modifiers that break down normal RTV and cause leaking, this specialty silicone has been tested to OEM specifications to ensure complete sealing. Gear Oil RTV Gasket Maker seeks and seals leak paths that cut gaskets cannot and can also be used to seal cut gaskets.