WHILE DRIVING ON INTERSTATE 68 GOING UP A MOUNTAIN AND TOWING A RV, UPON REACHING TOP OF THE MOUNTAIN HEARD A LOUD NOISE. STARTED SLOWING DOWN, PASSED THE GUARDRAIL, AND ALL OF A SUDDEN VEHICLE JACK KNIFED OUT OF CONTROL. RV IMPACT FORCED TRUCK OFF THE ROAD. SHATTERED THE REAR CAB. WHEN THEY TOWED VEHICLE TO DEALER, WAS TOLD BY THE MECHANIC THAT THIS WAS A COMMON PROBLEM BECAUSE BEARINGS FAILED DUE TO BEARING SPINS IN THE HOUSING UNIT FREEZING UP. *AK