How to Replace a Control Arm BushingRe-rubbering GM A-Body rear arms
Article updated October 2011
If you're having suspension issues with that classic GM car, it may be a worn control arm bushing. Control arm bushing replacement is a job you can do at home by following a few simple steps. First, though, let's cover the basics:
The rear upper and lower control arms on the 1964-72 GM A-body vehicles (Chevelle, GTO, 4-4-2, Buick GS) not only provide suspension travel but also secure the rear end to the vehicle. Each control arm has two pressed-in bushings, one at each end. The bushing is a metal cylinder with a rubber center and a tubular metal core for the mounting bolt to pass through.
Replacing these bushings is relatively easy, and you can save a lot of money doing it yourself at home. A machine shop will use a press to remove the old bushings, but there is a simple way to accomplish this task. We used a bottle jack and bench vise to push the rubber center and core out of the circular housing. If you use a penetrating lubricant on the bushing the night before, it doesn't take much pressure to push out the rubber. All four of the arms can be done the same way, but if you don't plan to remove the rear end, do them one at a time and replace the finished arm before removing the next one. This secures the rear assembly with three arms while you restore the one.
Having a floor jack (or trans jack if you have access to a lift) to support the rear end will make the removal of the control arms easier. Using a 3/4-inch wrench and socket set, loosen the nuts on both of the control-arm retaining bolts. If your bolts are rusty, soak them with lubricant the night before. Remove the bottom bolt first then access the top bolt through the hole in the frame. Hold the control arm as you remove the top bolt-you don't want this chunk of metal dropping on your foot. It might take a bit of prying and wiggling to get the top connection loose from the frame mount.
We used a cold chisel to dent the side of the empty bushing case, which also started to break the pressure-fit ends of the case away from the control arm. The stamped-steel control arm is pretty tough, so you don't have to worry about bending it during this process. A good place to do this part of the job is on a cement floor. Step on one end of the arm and pound the bushing on the other end. Obviously, a large hammer makes the job easier.
Use the dent and cut made in the side of the bushing case to create a long groove in the metal. Once you've cut the case about three quarters of the way down its length, you can then bend it inward on both sides, taking all the pressure off the ends. The folded case can then be easily hammered out of the arm. Now is the time to either sand the metal or, if rust is present, have the arm media-blasted. No sense putting a rusty part back into the car. We used a self-etching primer first and then a couple of coats of semi-flat black aerosol paint.
We used a couple of 2x4s and 4x4s to prop up the end of the restored control arm for the bushing installation. A little white grease or liquid lubrication on the contact ends of the bushing will facilitate installation. A large socket and hammer will easily install the new bushing—simply use care to install it straight into the hole. Pound it until the lip on the bushing is contacting the side of the control arm and you're done. Not counting time to cosmetically restore the arm, it should take about an hour of labor time to remove and replace each arm.
If your old bushings were really worn out, this control arm bushing replacement will make an immediate difference in how the car rides and handles, giving your suspension a good-as-new level of performance.