The ball joints of your front suspension are critical components. Their job is to allow the spindle to travel vertically with the suspension, but not tilt in or out towards the fenderwell or fender. If that is happening, then you'll have alignment and tire wear issues, necessitating replacing the ball joints. In this case, the project vehicle is a 2001 GMC Sierra pickup, but the process is similar for other vehicles as well.
Lift up the front of the vehicle using the jack and secure it on jack stands. Make sure the vehicle is completely secure on the jack stands before you crawl underneath it. Remove the front wheels using the tire iron and place them to the side, out of the workspace.
Place the jack underneath the lower control arm until it just contacts the arm. This is to catch the spring from launching out of the control arm when the upper ball joint is disconnected.
Unbolt the upper control arm from the spindle using the 1/2-inch ratchet and socket. Then unbolt the upper control arm at the frame using the 3/8-inch ratchet and socket. Remove the upper control arm and place it to the side. GM does not offer a replacement ball joint for the upper control arm and instead sells the entire control arm assembly. This is actually easier to install than having to press out the stock ball joint, which requires special tools, and is also more reliable than buying an aftermarket ball joint.
Bolt the replacement upper control arm to the frame using the 3/8-inch ratchet and socket, then bolt the ball joint on the upper arm to the spindle using the 1/2-inch ratchet and socket.
Unbolt the lower control arm from the spindle using the 1/2-inch ratchet and socket. Then slowly lower the jack to release tension on the spring and separate the ball joint from the lower control arm.
Use the pneumatic angle grinder with the cut-off wheel to cut "X" shapes into the rivets that secure the lower ball joint to the lower control arm. This will make it easier to remove the heads of the rivets using the chisel. Insert the chisel attachment into the pneumatic chisel and place the chisel head between the lower control arm and the head of the rivet. Pull the trigger and chisel off the heads of the rivets until they're off completely. Once they are, switch to the pointed attachment and place it in the center of the rivet, then pull the trigger to knock the rivets completely out of the lower control arm.
Slide out the stock ball joint and slide in the replacement ball joint. Then bolt it in place using the hardware provided with the ball joint and the 3/8-inch ratchet and socket. Jack up the lower control arm and bolt it to the spindle using the 1/2-inch ratchet and socket. Bolt the tires back on and lower the vehicle back onto the ground using the jack.
