AS A MECHANICAL ENGINEER AND ACCIDENT RECONSTRUCTIONIST I WAS ASKED TO EXAMINE THE FRONT AXLE OF A LATE MODEL FREIGHTLINER TRUCK-TRACTOR THAT HAD BEEN IN A LOSS-OF-STEERING-CONTROL TYPE ACCIDENT. THE ACCIDENT RESULTED IN A TOTAL LOSS OF THE TRACTOR, THE TRAILER, THE TRAILER LOAD AND INJURY TO THE DRIVER. UPON EXAMINING THE LEFT FRONT STEERING SPINDLE I NOTICED IT HAD SEPARATED FROM THE AXLE. THE PLACE WHERE THE SPINDLE CONNECTS TO THE AXLE IS EFFECTED BY AN INTERFERENCE FIT BETWEEN A SOLID CYLINDER AND A CYLINDRICAL HOLE WITH NO OTHER MEANS OF JOINING THE TWO PARTS. THE HOLE WAS CRACKED WHICH CAUSED A PARTIAL LOSS OF INTERENCE FIT WHICH ALLOWED THE SPINDLE TO WORK ITS WAY OUT OF THE HOLE. WHEN THIS OCCURS THERE IS LOSS OF LOAD SUPPORT BY THE WHEEL AND A LOSS OF STEERING. THERE WAS NO IMPACT DAMAGE TO THE WHEEL SO THE SEPARATION WAS THE CAUSE OF THE ACCIDENT NOT A RESULT OF THE ACCIDENT. THIS WAS CLEARLY A DEFECTIVE FRONT AXLE BUT IT IS NOT KNOWN AT THIS TIME IF IT IS A (1) DESIGN DEFECT , (2) MANUFACTURING DEFECT OR (3) A MATERIAL DEFECT. HOWEVER, THERE IS A DEFECT AND IT IS A VERY SERIOUS PROBLEM BECAUSE THERE ARE SEVERAL THOUSAND OF THESE TRUCK TRACTORS OPERATING RIGHT NOW WITH STEERING AXLES POTENTIALLY ABOUT TO FAIL AND WHEN THEY DO THE EFFECTS WILL BE CATASTROPHIC TO THE DRIVERS, OTHER MOTORISTS AND CARGOES. THE ONLY WAY TO CORRECT THIS PROBLEM IS TO STOP THE TRUCKS, RECALL THE TRUCKS AND REPLACE OR MODIFY THE SPINDLE-AXLE CONNECTION SO THAT THEY CAN'T SEPARATE. I KN