The truck is a 2008 F-450 pickup that I have owned since new, now with 60,000 miles. 5,000 miles ago I replaced the brake pads on both axles due to the material separating from the backing plate on one side of the rear axle. Have not had any issues until recently. The brakes are now what I can best describe as grabbing. Not pulling to either side, just grabbing. Quite severe at low speed. I removed the wheels and calipers, inspected the rotors. No signs of overheating or cracking. I used my portable grinder with sanding pads to go over both surfaces of all four rotors to remove any high spots, rust. The truck does sit covered in the driveway for extended periods of time. While the rotors look good, I reassembled the brakes, drove the truck and the problem persists. Before I spend $119 per rotor to replace, I am looking for a second opinion of the possible cause. The suspension looks good, no loose ball joints, tie rod ends. Tires are good, only 10k miles. You may be asking why I just do not have the rotors resurfaced, the reason is not many shops have the capability to turn these larger rotors. Any suggestions are much appreciated.