Engine Lubrication: Diagrams

6.9L - 7.3L Diesel Lubrication System

Lubrication oil is drawn out of the sump through the pick up screen and oil pick up tube to the oil pump. Oil pump flow is 45.4 liters (12 gallons) per minute at rated speed and a pressure of 275-482 kPa (40-70 psi). From the oil pump, oil is passed via drilled passageways in the crankcase to the oil cooler adapter then through the oil cooler. Oil flows around the outside of the heat exchanger tubes. (Coolant flows through the tubes). The oil passes around the tubes rearward to the oil filter header. At the oil filter header the oil meets the pressure regulating valve. This regulates the oil pressure to the oil filter and the engine oil galleries. The rear oil filter header also has a bypass valve which will open if the oil filter should become clogged. Five cross passages distribute oil to verticle passages which feed crankshaft main bearings, camshaft bearings and two tappet galleries. The piston cooling jets are fed from the same passage as the valve tappets. The connecting rod bearings are fed from the main bearings via drilled passages in the crankshaft. The timing gears are lubricated by oil splash. Oil passes through the hydraulic tappet rollers and up the hollow pushrods to lubricate the rocker arm assemblies and valve stems.