I WAS DRIVING UPHILL ON 4 LANE HIGHWAY WHEN I NOTICED SPEED DROPPING, I HAD DROPPED TO 50 MPH, THEN STARTED TO HEAR METAL BANGING, I WAS STARTING TO HEAD TO BURM WHEN SOME VERY LOUD METALLIC BANGS HAPPENED, AND ONE OR MORE WHEELS LOCKED UP AND SENT ME INTO A SPIN TO THE RIGHT, AND I HIT GAURD RAILS. I WAS ON RT. 68 EASTBOUND IN MARYLAND, ON SIDELING HILL. AFTER HAVING IT IN THE GARAGE THE MECHANICS TOLD ME THAT A GASKET OR SEAL LEAKED ON THE DIFFERENTIAL, THEY TOLD ME THEY HAVE NEVER HAD IT HAPPEN, NOR DO THEY NO WHY.