TM 9-6115-730-24
0003
LUBRICATION SYSTEM - Continued
Engine Lubrication
The engine oil pump is mounted to the bottom of the cylinder block inside the engine oil pan. The engine oil pump
pulls oil from engine oil pan and pushes the oil through the passage to the engine oil cooler and filter. The filtered
oil then enters the turbocharger oil supply line and main oil gallery. The main oil gallery distributes oil to main
bearings, piston cooling jets, and the camshaft bearing. Oil from the main oil gallery exits the front of the block
and enters a groove that is cast in the front housing. Oil enters the crankshaft through holes in the bearing surfaces
(journals) for the main bearing. Passages connect the bearing surface for the main bearing with the bearing
surface for the connecting rod. The front housing passage sends the oil flow in two directions. At the upper end of
the passage, oil is directed back into the block and up to cylinder head gallery through passage to the rocker arm
mechanism. Internal passages lubricate the oil pump idler gear bearing and camshaft idler gear bearing. Oil
passages in the crankshaft send oil from all the main bearings through the connecting rods to the connecting rod
bearings. The passages send oil from the camshaft bearing to pushrod lifters.
AIR INLET AND EXHAUST SYSTEM
The air inlet and exhaust system (Figure 6) consists of an air filter assembly, intake manifold, turbocharger,
exhaust manifold and muffler. Ambient air is drawn into the air filter assembly where it passes through the filter
elements. Airborne dirt is removed and trapped in the elements. Filtered air is drawn out of the air filter assembly
through air intake tubes to the turbocharger where it is pressurized and passed through an aftercooler coil in the
radiator. In cold weather, an ether starting aid is used to accelerate combustion The pressurized inlet air enters
the intake manifold to the combustion chambers and mixes with fuel from the fuel injectors. The engine exhaust
gases are released into the turbocharger, which is mounted on the exhaust manifold. The exhaust gases drive the
turbocharger, forcing large amounts of air into the intake manifold. After passing through the turbocharger, the
exhaust gases are channeled into a muffler to deaden the sound. The exhaust gases are vented upward from the
Figure 6. Air Inlet and Exhaust System.