KINGBOLT
kingbolt, kingpin, swivel pin
(noun) bolt that provides a steering joint in a motor vehicle
Source: WordNet® 3.1
Etymology
Noun
kingbolt (plural kingbolts)
The main bolt of a structure, especially the bolt in a motor vehicle that links the chassis to the axle, providing the steering pivot.
Synonyms
• kingpin
Source: Wiktionary
King"bolt`, n.
Definition: A vertical iron bolt, by which the forward axle and wheels of a
vehicle or the trucks of a railroad car are connected with the other
parts.
Source: Webster’s Unabridged Dictionary 1913 Edition