REAR AXLE SPINDLE SEALS LEAK CAUSING GREASE TO CONTAMINATE REAR BRAKE PADS AND CAUSING LOCK UP OF REAR WHEELS AND LOSS OF CONTROL. PAID FOR UPGRADE FROM FORD GARAGE WHICH FAILED TO RESOLVE THE PROBLEM. FORD GARAGE TOLD ME THAT PROBLEM CANNOT BE FIXED. I HAVE TALKED TO SEVERAL OTHER OWNERS OF FORD TRUCKS WITH SAME REAR END AS MINE AND THEY ARE HAVING THE SAME PROBLEM AS I AM. THIS IS A SAFETY ISSUE THAT SHOULD BE ADDRESSED BY FORD MOTOR COMPANY AS THESE VEHICLES ARE ON THE ROAD WAITING FOR AN ACCIDENT TO HAPPEN. AS IT IS I HAVE BEEN REPLACING SEALS AND BRAKE PADS EVERY 15,000 MILES TO AVOID A WRECK AT A COST OF 300.00 DOLLARS A REPAIR.