How to Replace the Upper Control Arm & Ball Jointby Don Bowman
The upper control arm and ball joint are located under the front of the vehicle and are an integral part of the steering and suspension system. If these are loose or broken, they should be replaced immediately, as the handling of the vehicle can be severely affected. The upper and lower control arms hold the spring in and are directly related to keeping the vehicle up off the tire. Depending on the year, make and model of the vehicle, the vehicle has a shock or a strut. The shock or strut is also affected if the upper control arm is bad.
Raise the front of the vehicle and support it by the frame with jack stands. Remove the front wheels using the air gun and a socket.
Place the floor jack under the lower control arm as close to the ball joint as possible. Raise the jack until it begins to lift the control arm. Make sure that the floor jack is positioned where it cannot slip off the control arm.
Remove the cotter pin in the upper control arm ball joint using the wire cutters. Remove the nut on the bottom of the upper ball joint using a wrench. Separate the ball joint using the ball joint separator tool. Insert the tool between the spindle and the upper control arm and hit it with a hammer until it comes loose from the spindle.
Remove the upper control arm by removing the nuts on the engine side of the arm holding it to the frame. Use a wrench for this, but as the bolts are loosened, keep the alignment shims together that are behind each nut. It will be necessary to replace these on the side they were removed from for the alignment.
Lift the upper control arm off and remove the upper ball joint using the ball joint installer kit. This procedure is only necessary if the new control arm does not come with a ball joint, which would be unusual.
Place the receiver over the bottom of the ball joint and the smaller pusher cylinder on the topside. Place the large C-clamp from the kit over the cylinders. Use the ½-inch drive air gun and socket to push the ball joint out. Reverse the process to install the ball joint. Install the upper control arm in reverse order of removal.
- Don Bowman, A.S.E. Certified Mechanic
Things You'll Need
- Floor jack
- Jack stands
- Ball joint separator
- Large hammer
- ½-inch drive air gun
- Set of ½-inch drive sockets
- Wire cutters
- Set of wrenches
- Ball joint installer kit
- When replacing an upper control arm, it is important to understand that the coil spring is compressed to half its unsprung height. It is normally compressed between the upper and lower control arms, which are connected on one end to the frame, and the other end to the spindle, via the ball joints. When the upper control arm is removed, the weight of the vehicle alone keeps the spring retained. If the lower control arm slips off the floor jack or jack stand, this would release the spring, possibly causing bodily harm or death.
Don Bowman has been writing for various websites and several online magazines since 2008. He has owned an auto service facility since 1982 and has over 45 years of technical experience as a master ASE tech. Bowman has a business degree from Pennsylvania State University and was an officer in the U.S. Army (aircraft maintenance officer, pilot, six Air Medal awards, two tours Vietnam).