Abstract: The present invention relates to an arrangement for mechanically driving a mechanism connected to an internal combustion engine. A push rod is mounted between the mechanism and a shaft rotatably mounted in the engine, one end of said rod being adapted to actuate the mechanism and the other end being adapted to resiliently engage against an arcuate surface on said shaft and to be given oscillating translation motion by said shaft on rotation. The invention is distinguished in that the end of the push rod engaging against the shaft is provided with two extensions at least partially embracing the arcuate surface on the shaft, said extensions guiding the position of a rod in a plane transverse to the shaft when said shaft rotates. The push rod thus requires no extra guidance and is simple to fit and to dismantle. The push rod preferably comprises two parts joined to each other via a jointing sleeve allowing a given degree of angular latitude between said parts.