Early automobiles most often used a straight beam front axle. This was a great solution for the time, as roads were rugged and the beam axle was capable of taking a lot of abuse. As the roads improved and cars could be driven faster, the solid beam front axle fell out of favor to independent front suspension (IFS). Throughout the 1930s auto manufacturers worked to improve the front suspension design, developing many interesting variations in the process, like the knee-action front suspension on many GM cars. But eventually, most used an upper and lower control arm, spindle, and spring design. This design has withstood the test of time and is still utilized on many cars today. But as good as the design is, it still requires routine maintenance.
Lubrication is the first key to keeping the front suspension working properly as well as replacement of the upper and lower ball joints. But don’t forget to service the upper and lower control arm bushings too. These bushings help isolate road noise, absorb shocks while driving, and provide a firm pivot point for the suspension to travel up and down. In most applications these bushings are simply steel and rubber, and over time the rubber breaks down and then allows too much slop in the control arm movement. Often this is felt in less-responsive steering or the car wandering in the lane while driving.
Often overlooked on many car restorations, it is a good practice when servicing the front suspension to replace the upper and lower control arm bushings. We join Mark Simpson in the shop to take us step-by-step through the process of replacing the lower control arm bushings on a torsion bar front suspension. Perhaps one of the most difficult things to change is the lower control arms, but only because of the list of components to be removed to get to the control arm. But by following some simple steps, Simpson demonstrates this task can be handled in most home shops and provide years of trouble-free driving in exchange.