Many enthusiasts find worn out Coil Spring Bushings (commonly called coil spring isolators), sway bar and strut mounts when installing their new lowering springs. PitStopUSA.com offers high quality polyurethane versions, as well as, new heavy duty end link kits.
Responsible for absorbing wheel motion and minimizing its effect on your ride, coil springs are probably one of the most recognizable components of your suspension. A less-easily recognized part are the coil spring isolators. Located at the top and bottom of each coil spring, these discs are what keep the harshest vibrations from being felt in the cab. The OE isolators are normally made of rubber. Rubber isolators are good at reducing these vibrations, but they don't last long.
Coil Spring Isolators are made with polyurethane, a material much sturdier than rubber. Entirely capable of shrugging off the repeated fluctuations of weight and pressure, coil spring isolators will hold up much longer than the OE did. This added longevity does come with a price, polyurethane is also firmer than rubber. This firmness does increase your NVH slightly, but most drivers agree that the phenomenally increased longevity of the part is well worth it.