Helpers - For Radius Leaf Type Springs
MV/Durastar/4000 - New Generation - Rear Single Axle - Helpers
HV/Workstar/7000 and Transtar/8000 - New Generation - Rear Single Axle - Helpers
4100, 4200, 4300 and 4400 - MV607 and MV607H (2002-22)
7300, 7400, 7500, 7600 and 7700; HV507, HV513, HV607 and HV613 - 8500 and 8600 - Transtar (2002-22)
For models with radius leaf type springs