Making sure you don't feel every bump in the road is the task handled by your coil springs. Your coil spring isolators, on the other hand, are made to create a buffer between your coil springs and control arms. This buffer keeps your coil springs from damaging your control arms, and vice-versa, while simultaneously helping to reduce vibrations from the road. The OE isolators installed on your vehicle are most likely made of rubber, a material prone to cracking and falling away due to the variable pressure.
Whiteline crafts all of their isolators with synthetic elastomer, a material proven to last much longer than the OE rubber. Protecting your suspension components while dealing with the pressure of the coil spring are both well within the capabilities of Whiteline's isolators. This synthetic elastomer is also firmer than rubber, potentially increasing your NVH once installed. However, the safety and dependability of your suspension as a whole is well worth it. Plus, Whiteline covers all of their isolators with a lifetime warranty handled in-house here at DST.
