THERE ARE PINS HOLDING TOGETHER THE DIFFERENTIAL IN MANUAL AND STANDARD TRANSMISSIONS. THIS PIN GETS WORN OUT AND FALLS OUT OF PLACE CAUSING THE DIFFERENTIAL GEARS TO EXPLODE OUT OF THE BOTTOM OF THE TRANSMISSION CAUSING CHUNKS OF METAL TO FALL AND HIT THE PAVEMENT LEAVING HAZARDS ON THE ROAD WAY AND IN THE PROCESS CAUSES TOTAL LOSS OF CONTROL BY LOCKING UP BOTH FRONT TIRES ON THE VEHICLE. I WAS A VICTIM OF THIS AND ALMOST STRUCK A VEHICLE HEAD ON AND IN THE PROCESS HIT SEVERAL OBSTACLE BEFORE THE VEHICLE CAM TO REST IN A DITCH. THE VEHICLE IS NOW AT AAMCO TRANSMISSION IN TULSA OK. ALL THIS INFORMATION ABOUT THE PINS ARE COMING FROM THEM. THIS HAPPENS IN ALL 1999 SATURN SL AND SL2 VEHICLES WITH THE STANDARD AND AUTOMATIC TRANSMISSIONS. MY VEHICLE IS THE 1999 SATURN SL2 WITH THE SOHC 5 SPEED TRANSMISSION. IF YOU TAKE A LOOK AT COMPLAINTS THERE ARE MANY BEARING THE SAME PROBLEMS. *TR