Does the 126 V8 117 engine oil pump have one (1) or two (2) plastic rail tensioners? When changing oil pan gasket in 81 500 sel I found some small plastic rail pieces floating around; looking up to the oil pump chain I saw only one small plastic rail tensioner on the drivers side but no corresponding plastic rail tensioner for the passenger side? I visually confirmed that car has new timing chain and upper rails on the heads and the usual telltale previous chain scratches in the driver side valve cover. Car runs excellent, chain is tight, new chain tensioner etc. and beautifully clean engine internals.