Tie Rod End For Truck

A Tie Rod End For Truck is used for allowing free rotation in two planes at the same time while preventing translation in any direction, including rotating in those planes. Combining two such joints with control arms enables motion in all three planes, allowing the front end of an automobile to be steered and a spring and shock (damper) suspension to make the ride comfortable.

A simple kingpin suspension requires that the upper and lower control arms (wishbones) have pivot axes that are parallel, and in strict geometric relationship to the kingpin, or the top and bottom trunnions, which connect the kingpin to the control arms, would be severely stressed and the Tie Rod End For Truck would suffer severe wear. In practice, many vehicles had elastomeric bearings in the horizontal pivots of the trunnions, which allowed some small amount of flexibility, however this was insufficient to allow much adjustment of caster to be made, and also introduced compliance where the suspension designer may not have desired it in his quest for optimum handling. Camber angle could generally be adjusted by moving both inner pivots of either the upper or lower control arm inwards or outwards by an exactly equal amount. But compliance of the control arm inner pivots, typically due to the use of elastomeric bearings, would again cause the trunnions to be stressed. The suspension designer's freedom was limited, it was necessary to have some compliance where it might not be wanted, and very little where more would have been useful in absorbing the fore and aft impact loading from bumps.