Vehicles manufactured after 1990 often have axle and differential housings sealed with RTV. Over time, extreme vehicle vibration, even rough roads, can cause the RTV bead to break. If the bead breaks and the vehicle loses the axle lube, the transmission gears begin to rub and wear.
 
Federal-Mogul's Fel-Pro® brand axle and differential replacement gaskets are precut for these applications. You don’t have to worry about applying an RTV and waiting for it to set up to seal. In addition, installing precut Fel-Pro gaskets helps eliminate the risk of contaminating the differential housing with RTV. That contamination can happen for a number of reasons, two of the most common being the difficulty of running a consistent sealing bead, and the possible extrusion of the RTV in or out of the housing by tightening the housing cover, or even breaking the bead.

Fel-Pro replacement precut gaskets eliminate the need for RTV.