Axles literally make your wheels turn, Axles transfer the torque from the drivetrain to your wheels. Excessive vibration is particularly bad as it can cause interference with ride characteristic, safety, comfort, and handling. When this starts happening to your axles you will have to replace them. The Jeep CJ-7 featured a wheelbase which is 10 inches longer than that of the CJ-5. The other main difference between CJ-5 and CJ-7 is chassis, which consisting of two parallel longitudinal main c-section rails. To help and improve vehicle stability and handling, the rear section of the chassis stepped out to allow the springs and shock absorbers to be mounted closer to the outside of the body. It was introduced for the 1976 model year.