1999 COACHMEN MIRADA Steeringlinkages Problems

ON THREE SEPARATE OCCASIONS (ON THE SAME TRIP) I EXPERIENCED TOTAL LOSS OF STEERING CONTROL AT 60 MPH DUE TO THE FRONT WHEELS OF MY MOTOR HOME HITTING STAGGERED BUMPS IN THE ROAD THAT SET OFF A HARMONIC VIBRATION. THE FRONT WHEELS WERE OSCILLATING FROM LOCK TO LOCK (I HEARD THEM HITTING THE STOPS) WITH NO INPUT FROM THE STEERING WHEEL. BRAKING EFFECT WAS ALSO SEVERELY REDUCED. I THOUGHT THE VEHICLE WAS GOING TO COME APART - THE NOISE WAS THAT DRAMATIC! THE WHEELS CONTINUED TO OSCILLATE UNTIL THE VEHICLE SLOWED TO 20 MPH. FORTUNATELY THE ROAD WAS STRAIGHT OR I WOULD HAVE LEFT IT FOR SURE! I CALLED COACHMEN (MOTORHOME MANUFACTURER) WHO REFERRED ME TO FORD (THE UNIT HAS A FORD SD53 CHASSIS). FORD INFORMED ME THAT THEY HAD NO REPORTED PROBLEMS WITH THIS UNIT. BUT THEY ALSO TOLD ME THAT 1999 WAS THE ONLY YEAR THAT THEY HAD...