Abstract: A trucktrailer turntable locking apparatus mounted on a tractor or trailer dolly frame is described in which at least one locking bar hinged on a cross frame member of the tractor or dolly frame is pivoted by an air ram into a locking position such that the respective ends of the bar will abut against the longitudinal side frame struts of the trailer bed proximate the turntable as the trailer articulates on the turntable thereby locking the respective frames of the tractor or dolly and trailer in longitudinal alignment. For added strength, the locking bar may be mounted on the cross frame member such that its respective ends also abut against the longitudinal side frames of the tractor or dolly when in the locking position. In the preferred embodiment two locking bars are provided fore and aft the trailer turntable.