Abstract: A hydraulic lash adjuster has a cylindrical body and a hollow plunger slidably received within the body, the upper portion of the plunger extending beyond the body and is provided with a semi-spherical end socketably received in the socket of a rocker arm. The plunger has an internal oil chamber in communication with the exterior of the body and its semi-spherical end is provided with a through passage whereby to effect lubrication of the rocker arm. A snap-fit oil metering valve is snapped into the passage in the semi-spherical end of the plunger to control flow through the aperture from the internal oil chamber of the plunger.