kingpin
It must be replaced as an assembly with the entire steering knuckle. If you check ebay, there might be just the ball joint for sale, but it will need to be pressed into your old steering knuckle.
Hub/bearing assembly to steering knuckle bolts, 77 ft lbs.Axle nut, 103 ft lbs.
Simplified: The steering linkage has to be conected to the wheel to make the car steer. The Wheel imounted to a Steering Nuckle, The nuckle holds the wheel in place, the tie rod end conects the steering linkage to the Knuckle and allows the Knuckle/WHeel assembly to go up and down over bumps and side to side when the steering says to.
The threads in a steering knuckle can be repaired by take the steering knuckle to a machine shop and they can repair the threads. It would probably be better and more economical to get another one from the boneyard.
The 2006 Chevrolet Impala had recalls on the 979 steering knuckle and the manual passenger seat adjuster. The steering knuckle recall is due to the possibility of a broken steering knuckle causing a loss of steering.
The ABS sensor is part of the hub wheel bearing assembly. The hub wheel bearing will have to be replaced. This involves removing the wheel, the hub axel nut and then three torx screws which attach the hub wheel bearing assembly to the steering knuckle. A puller tool will be neede to separate the hub bearing from the steering knuckle. If the hub bearing is heavily rusted to the steering knuckle you may need to heat the metal in order to loosen the rust connection.
First, raise and support the vehicle. Then remove the wheel and the tire assembly. Also remove the caliper from the steering knuckle, and then remove the caliper adapter assembly.
The steering knuckle.
Replacing a steering knuckle on a Chevy Colbalt is easy. All you have to is take the steering wheel off and replace the old one.
With the aid of ball joints and steering joints, the knuckle allows the spindle to move up and down for suspension, rotate left and right for steering.
Due to the special tools and expertise required to press the hub and bearing from the steering knuckle,this job should be left to a professional mechanic.However the steering knuckle and hub may be removed and the assembly taken to an automotive machine shop or qualified repair facility.