1981 CHEVROLET CORVETTE Steering Problems

I'VE HAD AN UPPER CONTROL ARM BOLT COME OUT 4 TIMES ON MY CAR CAUSING THE WHEEL TO TUCK UNDER THE CAR. I ALSO HAD A LOWER CONTROL ARM BOLT COME OUT ONCE. I'VE BEEN LUCKY, IT'S ALWAYS HAPPENED WHEN I WAS TURNING AROUND OR GOING SLOW. HOWEVER, THE FIRST TIME IT HAPPENED, I WAS PULLING AWAY FROM THE CURB IN FRONT OF MY HOUSE, AND IT SOUNDED LIKE A ROCK SHOT OUT FROM UNDER THE TIRE. I STOPPED AND TOOK A LOOK AT THINGS AND LOOKED AT THE STREET BUT DIDN'T SEE A IT OR BOLT OR ANYTHING, AND FIGURED IT WAS A ROCK. IT DROVE FINE, GOT ON THE FREEWAY AND MY CAR SEEED TO DRIFT TO THE RIGHT. I GAVE IT A NORMAL SMALL CORRECTION AND SHOT HALF WAY ACROSS THE LANE NEXT TO ME THEN BACK ACROSS MY LANE. LET'S JUST SAY I ALMOST LOST CONTROL...