I HAVE A 2005 PONTIAC VIBE AWD AND RECENTLY HAD MY OIL CHANGED AND WAS TOLD THEY FOUND A SLIGHT LEAK IN MY "REAR DIFFERENTIAL OR GEARBOX". THEY SAID THEY DIDNT KNOW WHAT CAUSED IT BUT SOMETIMES IF IT IS OVERFILLED THE PRESSURE CAN POP THE SEAL AND CAUSE A LEAK. THEY TOLD ME TO GET IT FIXED AS SOON AS I COULD BECAUSE IT COULD CAUSE MAJOR PROBLEMS FOR ME. I HAVE TWO QUESTONS, WHAT IS THIS "GEARBOX" AND SHOULD IT BE COVERED UNDER MY WARRANTY? I FEEL EVEN IF IT IS NOT COVERED UNDER MY WARANTY IT SHOULD BE SINCE THE FACTORY OR DEALERSHIP WOULD OBVIOUSLY HAVE BEEN THE ONE TO "OVERFILL" IT. THANK YOU.