1. RP 643 TMC Air Suspension Maintenance Guidelines
2. SAE Study 962152: Worn Shocks contribute to wheel hop and or greater tire load variance x4 = (+/- 80%)?, the primary effect of which is scalloped tires. Worn shocks are defined as those that have loss over half their dampening performance.
3. U.S. Department of Transportation and OECD / DEVINE analysis of Modern Truck Air Suspension found that once the shock worn past 50% dampening performance, road wear damage increased by over 20% as a result of increased air-ride tire load variance creating a jack-hammer type effect between the tire and pavement, in turn severely reducing tire life as well.