The most common components for wear are the ball and socket type, variously called tie rods, idler and pitman arms, and center links, which serve as the connection between the rack and pinion or steering gear and the front wheels.
The remaining principal components, such as the rack and pinion, steering gear, steering wheel and any power assist unit only need to be replaced when fluid cannot be retained (large visible leaks) or internal failure to the part (worn or broken gears, seized pump). This may only happen once in the life of a car. Regular service of power steering fluid will help to keep these principal components from premature failure or wear.
A rack and pinion system uses several large components. This includes your main-shaft, universal joints, and an underlying intermediate shaft which immediately responds to all your steering wheel movements.
This rack and pinion system is designed to make your car’s steering easier to turn with the added help of a power assisted pump or motor. The typical car sold these days now weighs over 3000 pounds and larger vehicles like trucks and SUVs often weigh over 5000 pounds. The steering rack along with this power assist system are what allow you to easily move all that heavy mass between the steering wheel and your tires without so much as breaking a sweat.