While most people know the benefits of upgrading a vehicle's suspension with polyurethane components, the Cab & Body Mounts are often overlooked. Factory mounts are constructed of rubber that breaks down over time and exposure to the elements. As they break down, they become less effective at isolating the cab from chassis noise and vibration. In extreme circumstances, worn body mounts can cause the body to shift on the frame and increase body roll. Numerous problems with components that attach to both the body and the chassis, such as mechanical shift linkage, are also indicators of worn body mounts.