I just finished changing all four of mine tonight. After 10 years and untold miles they were close to the same wear on each. Biggest problem was that one had suffered a return spring failure and pretty much destroyed the adjuster and magnet. I got four complete new sets from e-trailer in 2 days. I do have a grip with e-trailer concerning their packing skills. I had to reassemble three of them as they had come apart to include return springs and adjuster, shoe hold down springs off one shoe. All parts were still in the box. Now almost ready for our Oct. trip to Amish country in Ohio.