A steering linkage normally includes (used with a worm type gearbox).
1. A Pitman Arm
2. Centre Link
3. Idler Arm
4. Two Tie Rod Assemblies
5. Ball Sockets 1. Pitman Arm It transfers gearbox motion to the steering linkage. The pitman arm is splined to the gearbox sector (output) shaft. A lane nut and lock washer secure the arm to its shaft. The outer end of the pitman arm normally used a ball socket, which is also known as swivel join. 2. Centre link (Relay Rod) Center link is also called as relay rod. It is simply a steel bar that connects the right and left sides of the steering linkage. It has holes that accept the pitman arm, tie rod ends and idler arm. 3. Idler Arm The idler arm supports the end of centre link on the passenger side of the car. It is bolted (fitted) to the car frame. 4. Tie-Rod Assemblies There are two tie rod assemblies that are used to fasten the centre link to the steering knuckles. Ball sockets are normally used on both ends of both tie rods. An adjustment sleeve is provided for changing the length of the tie rod during wheel alignment. 5. Ball Sockets These are like ball joints. The ball joints provide a swivel connection between two parts. If the ball sockets are not fitted in the steering links, it will bend when the wheel will turn or move up and down over rough road. Ball socket are filled with grease to prevent friction and wear. Some ball sockets are scaled. Others have a grease fitting that allows chassis grease to he inserted with a grease gun.