The shop foreman at Murray’s Auto Clinic said that the Sunbeam needed new ball joints before the front wheels could be aligned. 
What is a ball joint and why is it important to alignment? Ball joints are one of the parts that attach the front wheels to the car’s frame. Each wheel has two ball joints, arranged in vertical line behind the wheel. They allow the wheels to swivel left and right. Worn ball joints cause imprecise alignment settings and a car that wanders on the road.
Ball joints are similar to the ball and socket in a human’s hip joint; the ball is attached to the leg and is held in place by a socket in the pelvis. This arrangement allows the leg to move forward and back and also side to side.
In a car, the ball joints allow the front wheels to pivot left and right but also tilt as the springs and suspension flex. To the right is one of the old upper ball joints removed from the car. You can see the ball in the middle of the picture, just below the threaded bolt. If you look closely, you will see a gap between the ball and the socket. This allowed the wheel to wobble in the vertical axis.
On each side of the car, the ball joints attach the wheel hub itself to the control arms, which in turn are bolted to the car.
In the photo to the right, the control arms are the clean black pieces at the top and bottom of the picture. The upper control arm is in the background and partially hidden; the lower one is prominent at the bottom; and the new piece in the center is a tie rod end, which was described in a recent post. This picture was taken after the front suspension was reassembled and shows, inter alia, a new blue shock absorber, green grease on the new lower ball joint, and a new brake hose. The upper ball joint is barely visible behind the brake hose at the top of the picture.
The upper ball joint is press fit into the control arm, and special tools are needed to force out the old one. As with the tie rod replacement, I borrowed special tools from the local Advance Auto store. In this picture, I am using a C-clamp tool to remove the ball joint from the upper control arm, the part sitting on the vise. The black cylindrical object pushes against ball joint. 
The pressure increases as the large screw (visible on the far right) is turned; this pressure causes the ball joint to pop out of the control arm itself.
The close up to the right shows knurled section of the ball joint that was pressed into a corresponding cylinder in the control arm. You can imagine the very tight fit that is needed to hold together important steering and suspension parts. The rust on this one made the fit even tighter.
The new upper ball joint was pressed in using the same tool shown above but flipped around to press into the control arm, not out. The lower ball joint is bolted in place, making that part of the job much easier.
Sunbeam 