2011 THOR MOTOR COACH FOUR WINDS Visibilitywiper Problems

WHILE DRIVING FROM WISCONSIN TO NORTH CAROLINA THE WEATHER CHANGED TO RAIN. I TURNED ON THE WIPERS OF THE MOTORCOACH AND WITHIN A FEW MINUTES THEY STOPPED AND CATCH ONCE IN A WHILE AND THEN COMPLETELY STOPPED. I HAD TO STOP ON THE SIDE OF THE ROAD AND FOUND THAT THE MOTOR WAS TURNING BUT THE WIPER ACTUATOR ARM HAD COME LOOSE. I MANAGED TO GET TO MY DESTINATION AND I CALLED THOR AND WAS TOLD I NEEDED TO HAVE THE ENTIRE WIPER SYSTEM REPLACE. THAT WOULD COST ABOUT $1,700.00. I WENT TO A LOCAL STORE AND PURCHASED LOCK WASHERS AND THREADLOCK AND REINSTALLED THE WIPER ACTUATOR ARM TO THE WIPER MOTOR. THE PROBLEM WAS FIXED, BUT I DO NOT KNOW FOR HOW LONG OR WHEN IT WILL FAIL AGAIN. THE WIPERS ON THIS MOTORHOME HAVE NEVER SEEMED TO WORK CORRECTLY AS THE LEFT WIPER GOES BEYOND THE WINDSHIELD TO...