The steering linkage is a combination of rods, and arms, that transmit the movement of the steering gear to the front wheels.
It must transmit this movement to the front wheels, while still allowing for any up-and down movement they may make, while the vehicle is in motion.
The type of steering mechanism, and the number of linkages, depends on the type of steering box, its location, and the type of suspension on the vehicle.
Passenger cars with independent suspension, and using a worm-type steering box, may have the steering box mounted so that the linkage is in front, or behind, the suspension cross-member.
When the linkage is behind, it is protected by the cross-member from possible damage, and the position of the steering box reduces the length of the steering column.
Steering wheel movement is relayed through the steering gear and Pitman arm, to a centre track rod. The centre track rod is connected to the Pitman arm at one end, and to a steering idler arm, at the other end.
The idler arm assembly is bolted to the vehicle frame, and the idler arm is positioned, parallel to the Pitman arm. It can then relay the steering box movement accurately to the opposite side.
A tie-rod on each side of the vehicle connects each wheel assembly with the centre track rod. Flexible joints on the track rod, and on the ends of the tie-rods, allow for steering and suspension movement.