Rocker Shaft Lock SetAnother TurboKraft original The TurboKraft 911 Rocker Lock Sets solve common engine oil leak problems seen at the valve covers. The original rocker shafts installed in the engine camshaft housings develop excessive free play, coming loose and shifting as the engine reaches operating temperature. When the rocker shafts move in the camshaft housing, they shift to the side resulting in support of only one end. Not only does this create a huge oil leak,