This invention pertains to the drive jaw structure of a device for installing a pipe under a finished surface such as a driveway or street. The drive jaws are each provided with a spring loaded shift lever and a slide bar; one end of the spring is anchored to a slide box structure, carrying the jaw assembly, and the opposed spring end is slidably engaged on the slide bar in a manner whereby proper manipulation of the shift lever will cause the associated drive jaw to be selectively shifted and maintained in a forward or reverse drive attitude.Both of the drive jaw assemblies are pivotally maintained in position relative to the slide box by means of a single removable rod, extending centrally, longitudinally of the top of the slide box.