NHTSA Complaint #10289897 — 2001 FORD F-350 SD

I WAS DRIVING MY 2001 FORD F350 TO WORK. JUST AS I TURNED OFF THE HIGHWAY MY TRUCK LURCHED AND THE REAR WHEELS BEGAN TO SKID. I PUT MY TRUCK INTO NEUTRAL AND THE REAR WHEELS BEGAN TO ROLL AGAIN. I COASTED TO A STOP ON THE SHOULDER OF THE ROAD. I TESTED THE BRAKES AND THEY WHERE FINE. I TRIED REVERSE AND FORWARD AND EVERYTHING SEEMED FINE. I WAS CLOSE TO WORK AND THE ROAD SHOULDER WAS VERY NARROW SO I DECIDED TO SEE IF I COULD GET TO WORK. THE TRUCK STARTED OUT FINE. HOWEVER WHEN IT SHIFTED TO 3RD GEAR IT LURCHED AGAIN AND THE REAR WHEELS BEGAN TO SKID. I MANUALLY SHIFTED BACK TO SECOND GEAR AND THE TRUCK RESUMED NORMAL OPERATION FOR THAT GEAR. AFTER TALKING TO A NUMBER OF TRANSMISSION MECHANICS THE CONSENSUS WAS CLEAR. THE 'MECHANICAL DIODE' ON THE DIRECT DRUM WAS SEIZED. THIS PROBLEM IS WELL DOCUMENTED. IT IS COMMON ON 2001 FORDS TRUCKS WITH THE 4R100 TRANSMISSION. THESE ARE THE ONLY FORD TRUCKS WITH THIS 'MECHANICAL DIODE'. AFTER APPROXIMATELY 6 MONTHS OF PRODUCTION FORD SWITCHED BACK TO USING A ROLLER SPRAG JUST AS IT HAD USED IN ALL AUTOMATIC TRUCK TRANSMISSIONS BEFORE AND AFTER. IF THIS CATASTROPHIC TRANSMISSION FAILURE HAD OCCURRED MOMENTS BEFORE OR AT ANY POINT THE NEXT DAY (SNOW RAIN MIX) THE RESULT WOULD HAVE BEEN TOTAL LOSS OF CONTROL OF THE VEHICLE. I HAVE HAD A TRANSMISSION SHOP REMOVE THE DEFECTIVE PART. THEY REPLACED IT WITH THE A REDESIGNED FORD PART THAT REPLACES THE 'MECHANICAL DIODE' WITH A ROLLER SPRAG. *TR