A rocker arm assembly for a valvetrain having a valve, a lash adjuster, and a camshaft lobe. The rocker arm assembly includes a shaft, a bearing rotatably supported by the shaft for engaging the lobe, and a rocker arm. The rocker arm has a pad for engaging the valve, and a socket for engaging the lash adjuster. A pair of walls are disposed between the pad and socket and define a valley for accommodating the shaft. A pair of upwardly-opening arc-shaped bearing surfaces are disposed longitudinally between the pad and the socket and are spaced laterally from each other. The bearing surfaces rotatably support the shaft when the bearing engages the lobe. A pair of retention elements extend from the walls into the valley above the bearing surfaces such that the shaft is prevented from moving out of the valley in absence of engagement between the bearing and the lobe.