Most trucks are built with a body-on-frame construction. The bed on the truck is bolted directly to the frame, but to minimize vibrations, the cab is separated from the frame by a series of rubber bushings, known as body mounts. Over time, the rubber in these mounts degrades, the cab will start to lower in height, and vibrations from the engine will be more prevalent. Swapping out the mounts is an involved process but can be done at home.
Measure the location of the cab on the frame using the tape measure and record these measurements. Note the distance between the rocker of the cab and the frame as well as the distance between the cab and the ground.
Unbolt the body mounts from one side of the truck using the 1/2-inch ratchet and socket. There are body mounts under the core support in the front and at least two on the side underneath the cab. Place the wood block on the jack and set the jack in line with a body mount. Lift the jack until the wood block touches the bottom of the cab, then continue jacking until there is approximately 1 to 2 inches between the top of the old cab mount and the bottom of the cab.
Slide out the old cab mount and insert the replacement mount. Lower the jack and repeat the process for the next cab mount on that side. Once all of them are done, loosely bolt the cab back to the frame and use the tape measure to ensure that the vehicle didn't shift from side to side in the process. If it did, push or pull the cab until it comes into alignment.
Repeat the process for the opposite side of the cab. Once all of the measurements are verified, tighten down all of the cab mount bolts using a 1/2-inch ratchet and socket.
