An engine includes a camshaft supported in a housing for rotation about an axis of rotation. A cam gear is attached to one end of the camshaft and includes a first thrust bearing surface. A thrust ring is attached to the cam gear and includes a second thrust bearing surface. A thrust ring retainer is attached to the housing with a plurality of bolts and includes a pair of thrust surfaces trapped between the first thrust bearing surface of the cam gear and a second thrust bearing surface of the thrust ring. The thrust ring retainer also defines a portion of a lubrication connection passage that facilitates pressure equalization among a plurality of lubrication galleries arranged in parallel adjacent the camshaft.