Inspect the linings every 9 650 km (6,000 mi) and any time the wheels are removed (tire rotation, etc.). Inspect the lining for wear by removing the plug and using the inspection hole. Replace the shoe and lining assemblies when the thickness of any lining is worn within 0.72 mm (0.030 in) of the shoe. Replace riveted shoe and lining assemblies when the lining is worn to within 0.76 mm (0.030 in) of any rivet head. Always replace shoe and lining assemblies as a complete axle set.