DESCRIPTION
The complete engine lubricating oil system is a combination of three separate systems. These are the main lubricating system, the piston cooling system and the scavenging oil system. Each system has its own oil pump. The main lube oil pump and piston cooling oil pump, although individual pumps, are both contained in one housing and driven from a common drive shaft. The scavenging oil pump is a separate pump. All the pumps are driven from the accessory gear train at the front of the engine. Parts of the complete oil system and a schematic arrangement of oil circulation are shown in Fig. 9-1.

Oil tubes at the center of each main bearing "A" frame conduct oil from the main manifold to the upper half of the main crankshaft bearings. Drilled passages in the crankshaft supply oil to the connecting rod bearings, damper, and accessory drive gear at the front of the crankshaft. Leak-off oil from the adjacent main bearings lubricates the crankshaft thrust bearings.
Oil from the main lube oil manifold enters the gear train at the rear of the engine, at the idler gear stubshaft bracket. Oil passages in the stubshaft bracket distribute the oil. One passage conducts oil to both the right and left bank camshaft drive gear stubshaft brackets and to a manifold connected to the turbocharger oil filter. After passing through the filter, the oil enters the return line in the manifold and flows back to the idler gear stubshaft. A passage in the idler gear stubshaft bracket directs lube oil to the upper and lower stubshaft bearings. Filtered oil enters the turbocharger oil system from the upper idler gear stubshaft.
An oil passage in the turbocharger filter head, parallel to the filter output line, is connected to a passage in the turbocharger oil manifold. An oil pressure line is connected between the manifold passage and the low oil pressure device in the governor.
Oil enters the hollow bore camshafts from the camshaft drive stubshafts. Radial holes in the camshaft conduct oil to each camshaft bearing. An oil line from one camshaft bearing at each cylinder supplies oil to the rocker arm shaft, rocker arm cam follower assemblies, hydraulic lash adjusters, and the injector rocker arm button. Leak-off oil returns to the oil pan through passages between the top deck and the oil pan.
Passages in the turbocharger conduct oil to the turbocharger bearings, idler gear, planet gear assembly, and auxiliary drive bore.
Considerable heat will remain in the metal parts of the turbine when the engine is shut down, and if the oil supply to the turbocharger was shut off suddenly, this heat would penetrate the turbo-charger bearing area. To prevent possible over-heating of the turbocharger, oil is automatically supplied to the turbocharger after stopping the engine.
Protection is provided against a hot oil condition by a thermostatic valve. Descriptive information is contained in Section 13, Protective Devices

DESCRIPTION
The main lube oil and piston cooling oil manifold, Fig. 9-3, is a one piece casting with cored passages. The manifold is mounted and doweled in the front end plate, under the accessory drive cover.
Fig. 9-3 - Lube Oil Manifold And Relief Valve
Connecting tubes passing through the accessory drive cover, protected against leakage by seal rings, connect the manifold to the discharge side of the main lube oil piston cooling oil pumps.
The purpose of the manifold is to transfer the oil supplied by the pumps to the main bearing oil header in the center of the engine. The manifold also transfers oil to the piston cooling oil header pipes on each side of the crankcase, just inside the oil pan mounting flange

DESCRIPTION
The lube oil pressure relief valve, Fig. 9-4, is installed on the lube oil manifold, inside the accessory gear train housing on the left side of the engine, Fig. 9-1. A cover plate provides access to the valve for inspection and adjustment The purpose of the valve is to limit the maximum pressure of the lube oil entering the engine oil system. When the lube oil pump pressure exceeds the spring tension on the valve, the valve will be lifted off its seat and relieve the excess pressure. This oil drains into the accessory housing and then into the oil pan.

The setting of the oil pressure relief valve connected to the lube oil manifold determines the maximum oil pressure at the main lube oil pump. It is not set by pressure gauges, but by a specific dimension from the top of the valve guide to the top of the valve holder.
To set valve, loosen the locknut, Fig. 9-4, and position the valve guide so that it extends 38.10 mm (1-1/2") above the safety plate.
This setting will permit a maximum oil pressure of about 862 kPa (125 psi) under cold oil conditions, and allow an adequate pressure for normal operation and hot oil.
Lubricating oil manifold pressure or pressure at the valve can be determined by applying a pressure gauge at the main lube oil pump discharge elbow.

DESCRIPTION
The piston cooling oil pipe is bolted at one end to a flange on the piston cooling oil manifold, and at the other end to the bottom of the cylinder liner. A pipe is located at each cylinder to direct a stream of oil through the piston carrier to the undercrown of the piston. Alignment of the piston cooling oil pipe is very important

DESCRIPTION
The oil strainer housing. Fig. 9-6, is a large box-shaped cast aluminum housing which is mounted on the right front side of the engine on the accessory drive cover. It contains independent strainers for the main oil pump supply and scavenging oil pump. There are two strainers for the main lube pump oil and one strainer screen for scavenging pump oil. with a separate oil inlet and discharge for each of the systems.
The two main lube oil pump strainers. Fig. 9-7, each consists of a replaceable element of a pleated perforated metal core covered with mesh screening, and a metal cylinder which encloses the element. The cylinder prevents collapse of the element in the event of a high pressure drop. The element is attached to the cylinder by a through bolt in the cylinder which runs through the base of the element and is secured with a locknut. The unperforated outer cylinder provides a constant head of oil since suction is from the bottom only and not through the entire length of the screen.
The flow of oil is from the bottom of the strainer between the cylinder and the mesh screen, through the mesh screen and the perforated metal core into the center of the element, then out the top of the strainer

When in place, they are held by a crab and handwheel on the stud between the holes. Each strainer is sealed at the top by a seal ring. Also, oil under pump pressure is admitted to a groove around each strainer, just below the seal, to prevent air
Entry in event of a leaky seal. A partition adjacent to the strainers, open at the bottom, separates them from the oil inlet area of the housing. Oil enters the strainers at the partition bottom and is taken up by thy pump through a cast passage in the housing.
The scavenging oil pump strainer, Fig. 9-8, has a rigid perforated metal screen which retains its shape and is easily cleaned. When the strainer is installed in the housing, it is held in position with three nuts. Two handwheels on swivel bolts secure a cover over the strainer and drain valves. The scavenging oil strainer inlet and outlet openings are shown in Fig. 9-6.
An oil level is maintained in the strainer housing up to the bottom of the overflow opening, Fig. 9-6. Excess oil returns to the oil pan sump. A spring-loaded valve, Fig. 9-9, is provided to drain the oil from the strainer housing into the oil pan sump, at the time of an oil change. An additional valve, Fig. 9-9, is used to drain the oil filter housing. Both valves are located under the filler cover and must be kept closed at all times except for the period of draining.

DESCRIPTION
The oil separator is an elbow-shaped cylindrical housing containing a wire mesh screen element. It is mounted on the turbocharger housing. An elbow assembly connects the oil separator to the eductor tube assembly in the exhaust stack, Fig. 9-10. The exhaust gases in the stack create a suction in the eductor tube, which draws up oily vapors from the engine through the separator element. The oil collects on the element and drains back into the engine. The gaseous vapors going through the element are discharged into the exhaust stack and vented to atmosphere.

The main lube oil and piston cooling oil pumps, Fig. 9-11, are contained in one housing. The two pumps are separated by a spacer plate between the sections of the pump body. Each has its individual oil inlet and discharge opening. The piston cooling pump gears at the end are narrower than the lube oil pump gears. The lube oil and piston cooling oil pump assembly is mounted in the center of the accessory drive housing and is driven by the accessory drive gear.

DESCRIPTION
The scavenging oil pump, Fig. 9-16, is a positive displacement, helical gear type pump. The pump body, split transversely for ease of maintenance, contains sets of mated pumping gears. The driving gears are retained on the pump drive gear shaft by keys. The idler shaft is held stationary in the housing by a set screw, and the driven pump gears rotate on this shaft on bushings pressed into the gear bores. The drive shaft turns in bushings pressed into the pump body. These bushings are made with thrust collars which protrude slightly above the pump body and absorb the thrust of the drive gears. The scavenging pump is mounted on the accessory housing in line with and to the left of the crankshaft, and is driven by the accessory drive gear.

DESCRIPTION
The turbocharger oil filter, Fig. 9-18, provides additional protection for the high speed bearings and other lubricated areas of the turbocharger, by filtering the oil just before it is admitted to the turbocharger. Oil enters the filter through a cast manifold and, after passing through the filter, returns to the upper idler gear stubshaft and into the turbocharger. The filter element is of pleated paper construction, and is disposable. The filter is mounted on the camshaft drive housing at the right bank of the engine. The filter head contains two check valves, Fig. 9-18. one to prevent lube oil from the soak back system from going into the turbocharger filter during soak back pump operation and the other to prevent lube oil from the turbocharger filter from entering the soak back system when the engine is running.

DESCRIPTION
To ensure lubrication of the turbocharger bearings prior to engine start. and the removal of residual heat from the turbo after engine shutdown, a separate lube oil pressure source is provided. This pressure source is controlled automatically through the engine "start" and "stop" controls.
An electrically driven pump drawing lube oil from the oil pan, pumps the oil through a soak back filter, Fig. 9-19, and the head of the turbocharger oil filter directly into the turbocharger bearing area, Fig. 9-1. The motor driven pump and filter are mounted on the side of the oil pan, Fig. 9-19.
Fig. 9-19 - Soak Back Oil Motor, Pump, And Filter Installation
CAUTION: If the soak back pump should fail to operate when the engine is shut down. restart the engine immediately and allow it to run for 15 minutes at idle speed with no load, to prevent damage to the turbocharger.
If engine is not restarted within two minutes of shutdown, do not restart the engine until soak back pump operation is restored and the engine has been allowed to cool down.
A pressure relief valve, Fig. 9-19, set at 379 kPa (55 psi), is located in the head of the filter. When the engine starts, and the motor driven pump is still running, main lube oil pressure from the engine driven pump becomes greater than the motor driven pump pressure. As there is no outlet for the lower pressure oil. the relief valve will open when the
pressure builds up to 379 kPa (55 psi), and the oil will return to the oil pan through a passage in the filter head mounting flange. Also located in the filter head is a bypass valve, Fig. 9-19, set at 483 kPa (70 psi). This valve will open to permit motor driven pump pressure to bypass a plugged filter element so that lubrication can be supplied to the turbocharger to prevent turbo damage.