38S21136 3412 INDUSTRIAL ENGINE Systems Operation

Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Introduction

NOTE: For Specifications with illustrations, make reference to Specifications for 3408C & 3412C Industrial Engines, SENR1136. If the
Specifications in SENR1136 are not the same as in the Systems Operation, Testing & Adjusting, look at the printing date on the front cover
of each book. Use the Specifications given in the book with the latest date.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Systems Operation
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Engine Design

3408C

Cylinder, Valve And Injection Pump Location

Number And Arrangement Of Cylinders . . . 65 degree V-8

Valves Per Cylinder . . . 4

Displacement . . . 18.0 liters (1099 cu in)

Bore . . . 137.2 mm (5.40 in)

Stroke . . . 152.4 mm (6.00 in)

Compression Ratio . . . 14.5:1

Type Of Combustion . . . Direct Injection

Direction Of Crankshaft Rotation (as viewed from flywheel end) . . . Counterclockwise

Direction Of Fuel Pump Camshaft Rotation (as viewed from pump drive end) . . . Counterclockwise

Firing Order (Injection Sequence) . . . 1-8-4-3-6-5-7-2

Valve Lash Setting

Inlet . . . 0.38 mm (.015 in)

Exhaust . . . 0.76 mm (.030 in)

NOTE: Front end of engine is opposite the flywheel end. Left side and right side of engine are as viewed from the flywheel end. No. 1
cylinder is the front cylinder on the left side. No. 2 cylinder is the front cylinder on the right side.

3412C

Cylinder, Valve And Injection Pump Location

Number And Arrangement Of Cylinders . . . 65 degree V-12

Valves Per Cylinder . . . 4

Displacement . . . 27.0 liters (1649 cu in)

Bore . . . 137.2 mm (5.40 in)

Stroke . . . 152.4 mm (6.00 in)

Compression Ratio . . . 14.5:1

Type Of Combustion . . . Direct Injection

Direction Of Crankshaft Rotation (as viewed from flywheel end) . . . Counterclockwise

Direction Of Fuel Pump Camshaft Rotation (as viewed from pump drive end) . . . Counterclockwise

Firing Order (Injection Sequence) . . . 1-4-9-8-5-2-11-10-3-6-7-12

Valve Lash Setting

Inlet . . . 0.38 mm (.015 in)

Exhaust . . . 0.76 mm (.030 in)

NOTE: Front end of engine is opposite the flywheel end. Left side and right side of engine are as viewed from the flywheel end. No. 1
cylinder is the front cylinder on the left side. No. 2 cylinder is the front cylinder on the right side.
Copyright 1991, 2004 Caterpillar Inc.
All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Systems Operation
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Fuel System

Fuel System Schematic

(1) Fuel tank. (2) Tank shutoff valve. (3) Fuel injection nozzle. (4) Fuel manifolds. (5) Fuel injection pump housing. (6) Bleed orifice. (7)
Fuel inlet line (from secondary filters). (8) Fuel inlet line (from primary filter). (9) Check valve. (10) Fuel transfer pump. (11) Secondary
fuel filter. (12) Primary fuel filter. (13) Fuel priming pump. (14) Fuel transfer pump relief valve.

There is one fuel injection pump and one fuel injection nozzle for each cylinder. The fuel injection pumps are located in the fuel injection
pump housing. The fuel injection nozzles (3) are located in the injection adapter in the cylinder head.

When the engine is running, fuel is pulled from the fuel tank through the fuel supply line and primary fuel filter (12) by fuel transfer pump
(10). The fuel is then pushed to secondary fuel filters (11), and into the fuel filter housing. A bleed orifice (6) in the fuel filter housing
cover vents air in the system through a line back to fuel tank (1). Fuel from the fuel filter housing goes through fuel inlet line (7) to fuel
manifolds (4) in fuel injection pump housing (5). The fuel manifolds supply fuel to each fuel injection pump.

Individual fuel injection lines carry fuel from the fuel injection pumps to each cylinder. One section of line connects between the fuel
injection pump and an adapter on the vllve cover base. Another section of line on the inside of the valve cover base connects between the
adapter and the fuel injection nozzle (3).
The fuel filters and priming pump are located in a compartment at the front of the fuel tank. The fuel transfer pump is mounted on a drive
adapter on the fuel injection pump housing, and is driven by a shaft connected to the fuel injection pump camshaft. Fuel transfer pump
relief valve (14) is located in the cover of the pump.

Fuel priming pump (13) is used before the engine is started to put pressure in the fuel system and to vent air from the system. A check
valve (9) located in the fuel transfer pump adapter housing will let fuel go around the fuel transfer pump when the priming pump is in use.

There is no bleed orifice or valve installed on the fuel injection pump housing to vent air from this part of the fuel system. Air trapped in
the fuel injection lines can be vented by loosening all of the fuel injection line nuts where they connect to the adapters in the valve cover
base. Move the governor lever to the low idle position. Crank the engine with the starting motor until fuel without air comes from the fuel
line connections. Tighten the fuel line nuts. This procedure is necessary because the fuel priming pump will not give enough pressure to
push fuel through the reverse flow check valves in the fuel injection pumps of a direct injection system.

An automatic timing advance unit is mounted on the front of the fuel injection pump camshaft. It is driven by the engine camshaft gear
inside the front timing gear housing. The automatic timing advance unit gives easier starting and smooth low speed operation. It will also
advance timing as engine speed increases to give correct engine operation efficiency.

Fuel Injection Pump

Cross Section Of The Fuel Injection Pump Housing

(1) Fuel manifold. (2) Inlet passage. (3) Check valve. (4) Pressure relief passage. (5) Pump plunger. (6) Spring. (7) Gear. (8) Fuel rack
(left). (9) Lifter. (10) Link. (11) Lever. (12) Camshaft.

The rotation of the lobes on the camshaft (12) cause lifters (9) and pump plungers (5) to move up and down. The stroke of each pump
plunger is always the same. The force of springs (6) hold lifters (9) against the cams of the camshaft.

The pump housing is a "V" shape (similar to the engine cylinder block). The 3408C has four pumps on each side and the 3412C has six
pumps on each side.

When the pump plunger is down, fuel from fuel manifold (1) goes through inlet passage (2) and fills the chamber above pump plunger (5).
As the plunger moves up it closes the inlet passage.
The pressure of the fuel in the chamber above the plunger increases until it is high enough to cause check valve (3) to open. Fuel under
high pressure flows out of the check valve, through the fuel line to the injection valve, until the inlet passage opens into pressure relief
passage (4) in the plunger. The pressure in the chamber decreases and check valve (3) closes.

The longer inlet passage (2) is closed, the larger the amount of fuel which will be forced through check valve (3). The period for which the
inlet passage is closed is controlled by pressure relief passage (4). The design of the passage makes it possible to change the inlet passage
closed time by rotation of the plunger. When the governor moves fuel racks (8), they move gears (7) that are fastened to pump plungers (5).
This causes a rotation of the plungers.

The governor is connected to the left rack. The spring load on lever (11) removes the play between the racks and link (10). The fuel racks
are connected by link (10). They move in opposite directions (when one rack moves in, the other rack moves out).

Fuel Injection Nozzles

The fuel injection nozzle is installed in an adapter in the cylinder head and is extended into the combustion chamber. The fuel injection
pump sends fuel with high pressure to the fuel injection nozzle where the fuel is made into a fine spray for good combustion.

Fuel Injection Nozzle

(1) Carbon dam. (2) Seal. (3) Passage. (4) Filter screen. (5) Inlet passage. (6) Orifice. (7) Valve. (8) Diameter. (9) Spring.

Seal (2) goes against the nozzle adapter and prevents leakage of compression from the cylinder. Carbon dam (1) keeps carbon out of the
bore in the nozzle adapter.

Fuel with high pressure from the fuel injection pump goes into inlet passage (5). Fuel then goes through filter screen (4) and into passage
(3) to the area below diameter (8) of valve (7). When the pressure of the fuel that pushes against diameter (8) becomes greater than the
force of spring (9), valve (7) lifts up. This occurs when the fuel pressure goes above the Valve Opening Pressure of the fuel injection
nozzle. When valve (7) lifts, the tip of the valve comes off of the nozzle seat and the fuel will go through the six small orifices (6) into the
combustion chamber.

The injection of fuel continues until the pressure of fuel against diameter (8) becomes less than the force of spring (9). With less pressure
against diameter (8), spring (9) pushes valve (7) against the nozzle seat and stops the flow of fuel to the combustion chamber.

The fuel injection nozzle can not be disassembled and no adjustments can be made.

Hydra-Mechanical Governor

The throttle lever, or governor control, is connected to the control lever on the engine governor. The governor then controls the amount of
fuel needed to keep the desired engine rpm at the throttle lever setting.
Hydra-Mechanical Governor

(1) Collar. (2) Bolt. (3) Lever assembly. (4) Upper spring seat. (5) Governor weights. (6) Governor spring. (7) Lower spring seat. (8) Thrust
bearing. (9) Valve. (10) Upper oil passage (in piston). (11) Piston. (12) Lower oil passage (in piston). (13) Sleeve. (14) Oil passage (in
cylinder). (15) Drive assembly. (16) Cylinder. (17) Pin. (18) Lever.

The governor has governor weights (5) driven by the engine through the drive assembly (15). The governor has a governor spring (6), valve
(9) and piston (11).

The valve and piston are connected to one fuel rack through pin (17) and lever (18). The pressure oil for the governor comes from the
governor oil pump, on top of the injection pump housing. The oil used is from the engine lubrication system. Pressure oil goes through oil
passage (14) and around sleeve (13). The throttle lever, or governor control, controls only the compression of governor spring (6).
Compression of the spring always pushes down to give more fuel to the engine. The centrifugal force of governor weights (5) always pulls
to get a reduction of fuel to the engine. When these two forces are in balance, the engine runs at the desired rpm (governed rpm).

The governor valve (9) is shown in the position when the force of the governor weights and the force of the governor spring are in balance.

When the engine load increases, the engine rpm decreases and the rotation of governor weights (5) will get slower. (The governor weights
will move toward each other). Governor spring (6) moves valve (9) down. This lets the oil flow from the lower oil passage (12) around the
valve (9) and through the upper oil passage (10) to fill the chamber behind piston (11). This pressure oil pushes the piston (11) and pin (17)
down to give more fuel to the engine. (The upper end of the valve stops the oil flow through the top of the piston, around the valve). Engine
rpm goes up until the rotation of the governor weights is fast enough to be in balance with the force of the governor spring.

When there is a reduction in engine load, there will be an increase in engine rpm and the rotation of governor weights (5) will get faster.
This will move valve (9) up. This stops oil flow from the lower oil passage (12), and oil pressure above piston (11) goes out through the
top, around valve (9). Now, the pressure between the sleeve (13) and piston (11) pushes the piston and pin (17) up. This causes a reduction
in the amount of fuel to the engine. Engine rpm goes down until the centrifugal force (rotation) of the governor weights is in balance with
the force of the governor spring. When these two forces are in balance, the engine will run at the desired rpm (governed rpm).

When engine rpm is at Low Idle, a spring-loaded plunger in lever assembly (3) comes in contact with a shoulder on the adjustment screw
for low idle. To stop the engine, push throttle lever to vertical position. This will let the spring-loaded plunger move over the shoulder on
the low idle adjustment screw and move the fuel rack to the fuel closed position. With no fuel to the engine cylinders, the engine will stop.

The governor oil pump supplies oil to the valve (9) to increase governor power and response. Oil from the governor oil pump gives
lubrication to the governor weight support (with gear), thrust bearing (8), and drive gear bearing. The other parts of the governor get
lubrication from "splash-lubrication" (oil thrown by other parts). Oil from the governor runs down into the housing for the fuel injection
pumps.

Fuel Ratio Control

Fuel Ratio Control (Engine Stopped)

(1) Inlet air chamber. (2) Valve. (3) Diaphragm assembly. (4) Oil drains. (5) Pressure oil chamber. (6) Large oil passages. (7) Oil inlet. (8)
Small oil passages. (9) Oil outlet. (10) Fuel rack linkage. (11) Valve.

With the engine stopped, valve (11) is in the fully extended position. The movement of fuel rack linkage (10) is not limited by valve (11).

Fuel Ratio Control (Ready For Operation)

(1) Inlet air chamber. (2) Valve. (5) Pressure oil chamber. (6) Large oil passages. (8) Small oil passages. (11) Valve.
When the engine is started, oil flows through oil inlet (7) into pressure oil chamber (5). From pressure oil chamber (5) the oil flows through
large oil passages (6), inside valve (11), and out small oil passages (8) to oil outlet (9).

A hose assembly connects inlet air chamber (1) to the inlet air system. As the inlet air pressure increases, it causes diaphragm assembly (3)
to move down. Valve (2), that is part of the diaphragm assembly, closes large and small oil passages (6 and 8). When these passages are
closed, oil pressure increases in pressure oil chamber (5). This increase in oil pressure moves valve (11) up. The control is now ready for
operation.

When the governor control is moved to increase fuel to the engine, valve (11) limits the movement of fuel rack linkage (10) in the "Fuel
On" direction. The oil in pressure oil chamber (5) acts as a restriction to the movement of valve (11) until inlet air pressure increases.

Fuel Ratio Control (Increase In Inlet Air Pressure)

(2) Valve. (4) Oil drains. (5) Pressure oil chamber. (10) Fuel rack linkage. (11) Valve.

As the inlet air pressure increases, valve (2) moves down and lets oil from pressure oil chamber (5) drain through large oil passages (6) and
out through oil drains (4). This lets valve (11) move down so fuel rack linkage (10) can move gradually to increase fuel to the engine. The
control is designed not to let the fuel increase until the air pressure in the inlet manifold is high enough for complete combustion. It
prevents large amounts of exhaust smoke caused by an air/fuel mixture with too much fuel.

The control movements take a very short time. No change in engine acceleration (rate at which speed increases) can be felt.

Automatic Timing Advance Unit

Automatic Timing Advance Unit

(1) Flange. (2) Weight. (3) Springs. (4) Slide. (5) Drive gear. (6) Camshaft.

The automatic timing advance unit is installed on the front of the camshaft (6) for the fuel injection pump and is gear driven through the
timing gears. The drive gear (5) for the fuel injection pump is connected to camshaft (6) through a system of weights (2), springs (3), slides
(4) and flange (1). Each one of the two slides (4) is held on drive gear (5) by a pin. The two weights (2) can move in guides inside flange
(1) and over slides (4), but the notch for the slide in each weight is at an angle with the guides for the weight in the flange. As centrifugal
force (rotation) moves the weights away from the center, against springs (3), the guides in the flange and the slides on the gear make the
flange turn a small amount in relation to the gear. Since the flange is connected to the camshaft for the fuel injection pump, the fuel
injection timing is also changed. No adjustment can be made in the timing advance unit.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Systems Operation
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Air Inlet And Exhaust System

The air inlet and exhaust system components are: air cleaner, turbocharger, inlet manifold (passages inside the cylinder block), cylinder
head, valves and valve system components, and exhaust manifold.

Air Inlet And Exhaust System

(1) Exhaust manifold. (2) Pipe to inlet manifold. (3) Engine cylinders. (4) Air inlet. (5) Compressor wheel. (6) Turbine wheel. (7) Exhaust
outlet.
Air Flow Schematic

(1) Exhaust manifold. (2) Pipe to inlet manifold. (4) Air inlet. (7) Exhaust outlet. (8) Turbocharger.

Clean inlet air from the air cleaner is pulled through air inlet (4) of the turbocharger by the turning of turbocharger compressor wheel (5).
The compressor wheel causes a compression of the air. The air then goes through pipe to inlet manifold (2) of the engine. When the inlet
valves open, the air goes into engine cylinders (3) and is mixed with the fuel for combustion.

When the exhaust valves open, the exhaust gases go out of the engine cylinders and into exhaust manifold (1). From exhaust manifold, the
exhaust gases go through the blades of turbine wheel (6). This causes the turbine wheel and compressor wheel to turn. The exhaust gases
then go out exhaust outlet (7) of the turbocharger.

Aftercooler

The aftercooler cools the air coming out of the turbocharger before it goes into the inlet manifold. The aftercooler is located toward the rear
of the engine between the cylinder heads. Coolant from the water pump flows through a pipe into the aftercooler. It flows through the core
assembly, then out of the aftercooler through a different pipe into the rear of the cylinder block. Inlet air from the compressor side of the
turbocharger flows into the aftercooler through pipes. The air passes through the core assembly. This lowers the temperature of the air to
approximately 93°C (200°F). The cooler air goes out the bottom of the aftercooler into the inlet manifold. The purpose of this is to make
the air going into the combustion chambers more dense. The more dense the air is, the more fuel the engine can burn efficiently. This gives
the engine more power.

Turbocharger

The turbocharger is installed at the top, rear of the engine on a cross pipe for the two exhaust manifolds. All the exhaust gases from the
engine go through the turbocharger.
Typical Example

(1) Turbocharger. (2) Cross pipes. (3) To exhaust manifold.

Turbocharger

(4) Air inlet. (5) Compressor wheel. (6) Turbine wheel. (7) Exhaust outlet. (8) Compressor housing. (9) Oil inlet port. (10) Thrust collar.
(11) Thrust bearing. (12) Turbine housing. (13) Spacer. (14) Air outlet. (15) Oil outlet port. (16) Bearing. (17) Coolant passages. (18)
Bearing. (19) Exhaust inlet.

The exhaust gases go through the blades of turbine wheel (6). This causes the turbine wheel and compressor wheel (5) to turn, which
causes a compression of the inlet air.

When the load on the engine is increased, more fuel is put into the engine. This makes more exhaust gases and will cause the turbine and
compressor wheels of the turbocharger to turn faster. As the turbocharger turns faster, it gives more inlet air and makes it possible for the
engine to burn more fuel and will give the engine more power.

Maximum rpm of the turbocharger is controlled by the rack setting, the high idle speed setting and the height above sea level at which the
engine is operated.
 If the high idle rpm or the rack setting is higher than given in the TMI (Technical
Marketing Information) or Fuel Setting And Related Information Fiche (for the height
above sea level at which the engine is operated), there can be damage to engine or
turbocharger parts. Damage will result when increased heat and/or friction, due to the
higher engine output, goes beyond the engine cooling and lubrication systems abilities.

Bearings (16 and 18) for the turbocharger use engine oil under pressure for lubrication. The oil comes in through the oil inlet port (9) and
goes through passages in the center section for lubrication of the bearings. Oil from the turbocharger goes out through the oil outlet port
(15) in the bottom of the center section and goes back to the engine lubrication system.

This type turbocharger has coolant passages (17) around the bearings to cool the oil in these areas. Engine coolant is taken from the top,
rear of the engine and sent into the rear of the turbocharger (center section). The coolant flows through the passages around the bearings,
and out the front of the turbocharger (center section) back to the radiator top tank.

The fuel rack adjustment is done at the factory for a specific engine application. The governor housing and turbocharger are sealed to
prevent changes in the adjustment of the rack and the high idle speed setting.

Valve System Components

The valve system components control the flow of inlet air and exhaust gases into and out of the cylinders during engine operation.

The crankshaft gear drives the camshaft gear. The camshaft gear must be timed to the crankshaft gear to get the correct relation between
piston and valve movement.

The camshaft has two cams for each cylinder. One cam controls the exhaust valves, the other controls the inlet valves.
Valve System Components

(1) Inlet bridge. (2) Inlet rocker arm. (3) Push rod. (4) Rotocoil. (5) Valve spring. (6) Valve guide. (7) Inlet valves. (8) Lifter. (9) Camshaft.
Valve System Components (Typical Illustration)

(1) Inlet bridge. (2) Inlet rocker arm. (7) Inlet valves. (10) Exhaust rocker arm. (11) Exhaust bridge. (12) Exhaust valves.

As the camshaft turns, the lobes of camshaft (9) cause lifters (8) to go up and down. This movement makes push rods (3) move rocker arms
(2 and 10). Movement of the rocker arms makes the bridges move up and down on dowels mounted in the cylinder head. The bridges let
one rocker arm open and close two valves (inlet or exhaust). There are two inlet and two exhaust valves for each cylinder.

Rotocoils (4) cause the valves to turn while the engine is running. The rotation of the valves keeps the deposit of carbon on the valves to a
minimum and gives the valves longer service life.

Valve springs (5) cause the valves to close when the lifters move down.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Systems Operation
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Lubrication System

Oil Flow Through The Engine Oil Cooler And Engine Oil Filters

Schematic Of Oil Flow

(1) To oil manifold. (2) Filter bypass valve. (3) Engine oil cooler. (4) Cooler bypass valve. (5) Engine oil pump. (6) Oil pan. (7) Engine oil
filters.

With the engine warm (normal operation), oil is pulled from oil pan (6) through a suction bell assembly and pipe to engine oil pump (5).
The engine oil pump sends oil to a passage in the cylinder block. The oil then goes through engine oil cooler bypass valve (4) into engine
oil cooler (3). The oil goes out of the engine oil cooler through engine oil filters (7). The clean oil then goes through engine oil filter bypass
valve (2), then into the oil manifold on the right side of the cylinder block.

When the engine is cold (starting condition), bypass valves (2 and 4) open because cold oil with high viscosity causes a restriction to the oil
flow through engine oil cooler (3) and engine oil filters (7). With the bypass valves open, oil flows directly through passages in the valve
body to the oil manifold.

When the oil gets warm, the pressure difference at the bypass valves decreases and the bypass valves close. This gives normal oil flow
through engine oil cooler (3) and engine oil filters (7).

The bypass valves will also open when there is a restriction in the engine oil cooler or engine oil filters. This action does not let an engine
oil cooler or engine oil filter with a restriction prevent the lubrication of the engine.

There is also a bypass valve in engine oil pump (5). This bypass valve controls the pressure of the oil from the engine oil pump. The engine
oil pump can put more oil into the system than is needed. When there is more oil than needed, the oil pressure goes up and the bypass valve
will open. This lets the oil that is not needed to go back to the inlet oil passage of the engine oil pump.

Oil Flow In The Engine

Schematic Of Oil Flow In The 3408C Engine

(1) Passage is plugged. (2) Passage (to rear idler gear). (3) Passage (to rocker arm shaft). (4) To turbocharger. (5) Passage (to fuel injection
pump housing, governor and fuel ratio control). (6) Rocker arm shaft. (7) Passages (to rocker arm shaft and valve lifters). (8) Passages (to
valve lifters). (9) Camshaft bearing bores. (10) Piston cooling jets. (11) To SCAC water pump. (12) Oil manifold (left side). (13) To timing
gear housing. (14) Passage (to front idler gear). (15) Oil supply line (to manifold in cylinder block). (16) Oil manifold (right side). (17)
Main bearing bores.

The oil manifolds are cast into the sides of the cylinder block. Oil goes into oil manifold (16) from the bypass valve body. From oil
manifold (16) oil is sent to oil manifold (12) through drilled passages in the cylinder block that connect main bearing bores (17) and
camshaft bearing bores (9). Oil goes through holes in the bearings and gives them lubrication. Oil from the main bearings goes through
holes drilled in the crankshaft to give lubrication to the connecting rod bearings. A small amount of oil from the oil manifolds goes through
piston cooling jets (10) to make the pistons cooler.

Oil goes through grooves in the outside of the front and rear camshaft bearings to passages (7 and 8). The oil in these passages gives
lubrication to the valve lifters and rocker arm shafts. Holes in the rocker arm shafts lets the oil give lubrication to the valve system
components in the cylinder head.

The fuel injection pump and governor gets oil from passage (5) in the cylinder block. There is a small gear pump between the injection
pump housing and the governor. This pump sends oil under pressure for the hydraulic operation of the hydra-mechanical governor. The
automatic timing advance unit gets oil from the injection pump housing, through the camshaft for the fuel injection pumps.

The idler gear bore gets oil from passage (14) in the cylinder block, oil then goes through the shaft for the bearings of the idler gear
installed on the front of the cylinder block.

The bearing for the balancer gear at the rear of the engine (3408C only) gets oil through a passage in the balancer gear shaft that is
connected to passage (2).
Turbocharger Lubrication (Typical Example)

(18) Oil supply line (to turbocharger). (19) Oil drain line (from turbocharger).

Oil supply line (18) gives oil to the turbocharger impeller shaft bearings. The oil goes out of the turbocharger through oil drain line (19) to
the flywheel housing.

Oil that gives pressure lubrication to gear shafts and bearings then flows free to give lubrication to the gear teeth. After the oil for
lubrication has done its work it flows back to the oil pan.

Schematic Of Oil Flow In The 3412C Engine

(1) Passage is plugged. (3) Passage (to rocker arm shaft). (4) To turbocharger. (5) Passage (to fuel injection pump housing, governor and
fuel ratio control). (6) Rocker arm shaft. (7) Passages (to rocker arm shaft and valve lifters). (8) Passages (to valve lifters). (9) Camshaft
bearing bores. (10) Piston cooling jets. (11) To SCAC water pump. (12) Oil manifold (left side). (13) To timing gear housing. (14) Passage
(to front idler gear). (15) Oil supply line (to manifold in cylinder block). (16) Oil manifold (right side). (17) Main bearing bores.
Copyright 1991, 2004 Caterpillar Inc.
All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Systems Operation
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Cooling System

Jacket Water Aftercooler

Cooling System Schematic

(1) Aftercooler elbow. (2) Aftercooler. (3) Front housing. (4) Temperature regulator housing. (5) Bypass lines. (6) Water cooled exhaust
manifold. (7) Jacket water coolant source. (8) Water cooled turbocharger. (9) Engine oil cooler. (10) Jacket water pump.

This engine has a pressure type cooling system. A pressure type cooling system gives two advantages. The first advantage is that the
cooling system can have safe operation at a temperature that is higher than the normal boiling (steam) point of water. The second advantage
is that this type system prevents cavitation (the sudden making of low pressure bubbles in liquids by mechanical forces) in the water pump.
With this type system, it is more difficult for an air or steam pocket to be made in the cooling system.

In normal operation (engine warm), jacket water pump (10) receives coolant through the inlet connection. The jacket water pump (10)
forces water out in two directions. Part of it flows to the aftercooler (2). The coolant goes through the aftercooler core and enters into the
cylinder block at the top rear through aftercooler elbow (1). Part of the coolant flows through the engine oil cooler (9) and into the side of
the cylinder block.

Coolant moves through the cylinder block to the cylinder heads. The coolant then goes to the temperature regulator housing (4). The
temperature regulators are open and most of the coolant goes through the outlets and back to the coolant source.

NOTE: The water temperature regulator is an important part of the cooling system. It divides coolant flow between jacket water coolant
source (7) and bypass lines (5) as necessary to maintain the correct temperature. If the water temperature regulator is not installed in the
system, there is no mechanical control, and most of the coolant will take the path of least resistance through the bypass. This will cause the
engine to overheat in hot weather. In cold weather, even the small amount of coolant that goes back to the coolant source is too much, and
the engine will not get to normal operating temperatures.

When the engine is cold, the water temperature regulator is closed, and the coolant is stopped from going back to the coolant source. The
coolant goes from the temperature regulator housing (4) back to the jacket water pump (10) through bypass lines (5).
Some of these engines are equipped with a water cooled exhaust manifold (6) and a water cooled turbocharger (8). The coolant for the
exhaust manifold comes from the back of the cylinder head through the exhaust manifold and out into the water temperature regulator
housing. The coolant for the turbocharger comes from the engine oil cooler (9) through the tube to the turbocharger. The coolant goes out
of the turbocharger and into the water cooled exhaust manifold.

Separate Circuit Aftercooler

Cooling System Schematic

(1) Separate circuit coolant source. (2) Aftercooler. (3) Water cooled exhaust manifold. (4) Front housing. (5) Temperature regulator
housing. (6) Bypass lines. (7) Separate circuit water pump. (8) Water cooled turbocharger. (9) Engine oil cooler. (10) Water pump. (11)
Jacket water coolant source.

Jacket Water System

This engine has a pressure type cooling system. A pressure type cooling system gives two advantages. The first advantage is that the
cooling system can have safe operation at a temperature that is higher than the normal boiling (steam) point of water. The second advantage
is that this type system prevents cavitation (the sudden making of low pressure bubbles in liquids by mechanical forces) in the water pump.
With this type system, it is more difficult for an air or steam pocket to be made in the cooling system.

In normal operation (engine warm), water pump (10) receives coolant through the inlet connection and sends the coolant to engine oil
cooler (9) and the oil cooler bypass. The engine oil cooler outlet sends the coolant from the cooler and bypass to the engine cylinder block.
The coolant to the cylinder block circulates through the block up through the cylinder heads, on to the water temperature regulator housing
(5). Part of the coolant in water temperature regulator housing (5) flows into water pump (10), and part of the coolant passes through open
water temperature regulators through the outlet connections to be cooled. The water pump (10) will pump the cooled coolant through the
engine to keep the cycle going.
These engines are equipped with water cooled exhaust manifold (3) and water cooled turbocharger (8). The coolant for the exhaust
manifold comes from the back of the cylinder head through the exhaust manifold and out into the water temperature regulator housing (5).
The coolant for water cooled turbocharger (8) comes from the engine oil cooler through the tube to the water cooled turbocharger. The
coolant goes out of the water cooled turbocharger and into water cooled exhaust manifold (3).

NOTE: The water temperature regulator is an important part of the cooling system. It divides coolant flow between the coolant source and
bypass lines (6) as necessary to maintain the correct temperature. If the water temperature regulator is not installed in the system, there is
no mechanical control, and most of the coolant will take the path of least resistance through the bypass. This will cause the engine to
overheat in hot weather. In cold weather, even the small amount of coolant that goes through the radiator or heat exchanger is too much,
and the engine will not get to normal operation temperatures.

When the engine is cold, the water temperature regulators are closed. The coolant in the water temperature regulator housing (5) flows
through bypass lines (6) to water pump (10). The coolant continues to flow through system as described above except the coolant does not
flow out to be cooled.

Separate Circuit Aftercooler (SCAC) System

The aftercooler (2) is cooled by a separate circuit. The separate circuit is used to maintain a specific and constant water temperature. Water
is pumped from separate circuit coolant source (1) by separate circuit water pump (7) through the aftercooler and back to the water supply.

Heat Exchanger Cooled System

Example Of Heat Exchanger Cooled System

(1) Water cooled turbocharger. (2) Aftercooler. (3) Connection [inlet for engine water return (either side)]. (4) Vent lines. (5) Water
temperature regulator (both sides). (6) Auxiliary water pump. (7) Connection (outlet for engine water). (8) Engine water pump. (9) Duplex
filter. (10) Heat exchanger. (11) Oil cooler bypass or marine gear cooler. (12) Engine oil cooler. (13) Water cooled exhaust manifold.

When the engine is cooled by the heat exchanger system, auxiliary water pump (6) is used to constantly pump filtered water from another
source (either sea water or storage water) through the heat exchanger. When the engine reaches a temperature high enough to open the
regulators, the coolant flow is directed around heat exchanger core (10) and then back to the expansion tank. The cooled coolant in the
expansion tank is then picked up by engine water pump (8) and directed back through the engine.

Coolant Conditioner (An Attachment)

Some conditions of operation have been found to cause pitting (small holes in the metal surface) from corrosion or cavitation erosion (wear
caused by air bubbles in the coolant) on the outer surface of the cylinder liners and the inner surface of the cylinder block next to the liners.
The addition of a corrosion inhibitor (a chemical that gives a reduction of pitting) can keep this type of damage to a minimum.

The "spin-on" coolant conditioner elements, similar to the fuel filter and engine oil filter elements, fasten to a base that is mounted on the
engine or is remote mounted. Coolant flows through lines from the water pump to the base and back to the block. There is a constant flow
of coolant through the element.

The element has a specific amount of inhibitor for acceptable cooling system protection. As coolant flows through the element, the
corrosion inhibitor, which is dry material, dissolves (goes into solution) and mixes to the correct concentration. Two basic types of
elements are used for the cooling system, and they are called the "Precharge" and the "Maintenance" elements. Each type of element has a
specific use and must be used correctly to get the necessary concentration for cooling system protection. The elements also contain a filter
and should be left in the system so coolant flows through it after the conditioner material is dissolved.

The "Precharge" element has more than the normal amount of inhibitor, and is used when a system is first filled with new coolant. This
element has to add enough inhibitor to bring the complete cooling system up to the correct concentration.

The "Maintenance" elements have a normal amount of inhibitor and are installed at the first change interval and provide enough inhibitor to
keep the corrosion protection at an acceptable level. After the first change period, only "Maintenance" elements are installed at specified
intervals to give protection to the cooling system.

Do not use any Methoxy Propanol/Based Antifreezes or coolant in the Cooling System.
Methoxy Propanol will cause some seals and gaskets to deteriorate and fail. Do not use
Dowtherm 209 Full-Fill in a cooling system that has a coolant conditioner. These two
systems are not compatible (corrosion inhibitor is reduced) when used together.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Systems Operation
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Basic Block

Cylinder Block, Liners And Heads

The cylinders in the left side of the block make an angle of 65 degrees with the cylinders in the right side of the block. The main bearing
caps are fastened to the block with two bolts per cap.

The cylinder liners can be removed for replacement. The top surface of the block is the seat for the cylinder liner flange. Engine coolant
flows around the liners to keep them cool. Three O-ring seals around the bottom of the liner make a seal between the liner and the block.

The engine has a single, cast head on each side. Four vertical valves (two inlet and two exhaust), controlled by a pushrod valve system, are
used per each cylinder. The opening for the fuel nozzles is located between the four valves. Series ports (passages) are used for both inlet
and exhaust valves.

A steel spacer plate is used between the cylinder head and block. A thin gasket is used between the (plate and liners) and the block to seal
water and oil. A thick gasket of metal and asbestos is used between the plate and the head to seal combustion gases, water and oil.

The size of the pushrod openings through the head permits the removal of the valve lifters with the head installed.

Valve guides without shoulders are pressed into the cylinder head.

Pistons, Rings And Connecting Rods

The aluminum pistons have three rings; two compression rings and one oil ring. All rings are located above the piston pin bore. The two
compression rings are of the Keystone type, which have a tapered shape. The seat for the rings is an iron band that is cast into the piston.
The action of the rings in the piston groove, which is also tapered, helps prevent seizure of the rings caused by too much carbon deposits.
The oil ring is a standard (conventional) type. Oil returns to the crankcase through openings in the oil ring groove.

The piston pin is held in place by two snap rings that fit in grooves in the pin bore of the piston. The connecting rod has a taper on the pin
bore end. This gives the rod and piston more strength in the areas with the most load.

Oil spray tubes, located on the cylinder block main webs, direct oil to cool and give lubrication to the piston components and cylinder
walls.

Crankshaft

The crankshaft changes the combustion forces in the cylinder into usable rotating torque which powers the machine. Vibration, caused by
combustion impacts along the crankshaft, is kept small by a vibration damper on the front of the crankshaft.

There is a gear at the front of the crankshaft to drive the timing gears and the engine oil pump. Seals and wear sleeves are used at both ends
of the crankshaft for easy replacement and a reduction of maintenance cost. Pressure oil is supplied to all bearing surfaces through drilled
holes in the crankshaft. The crankshaft is supported by five main bearings on the 3408C and seven main bearings on the 3412C. A thrust
plate at either side of the center main bearing controls the end play of the crankshaft.

Camshaft

The engine has a single camshaft that is driven at the front end. It is supported by five bearings on the 3408C and seven bearings on the
3412C. As the camshaft turns, each cam (lobe) (through the action of the valve system components) moves either two exhaust valves or
two inlet valves for each cylinder. The camshaft gear must be timed to the crankshaft gear. The relation of the cam (lobes) to the camshaft
gear cause the valves in each cylinder to open and close at the correct time.

Vibration Damper
Cross Section Of A Vibration Damper

(1) Flywheel ring. (2) Rubber ring. (3) Inner hub.

The twisting of the crankshaft, due to the regular power impacts along its length, is called twisting (torsional) vibration. The vibration
damper is installed on the front end of the crankshaft. It is used for reduction of torsional vibrations and stops the vibration from building
up to amounts that cause damage.

The damper is made of a flywheel ring (1) connected to an inner hub (3) by a rubber ring (2). The rubber makes a flexible coupling
between the flywheel ring and the inner hub.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Systems Operation
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Electrical System

The electrical system can have three separate circuits: the charging circuit, the starting circuit and the low amperage circuit. Some of the
electrical system components are used in more than one circuit. The battery (batteries), circuit breaker, ammeter, cables and wires from the
battery are all common in each of the circuits.

The charging circuit is in operation when the engine is running. An alternator makes electricity for the charging circuit. A voltage regulator
in the circuit controls the electrical output to keep the battery at full charge.

The starting circuit is in operation only when the start switch is activated.

The electrical systems include a Diagnostic Connector which is used when testing the charging and starting circuits.

The low amperage circuit and the charging circuit are both connected to the same side of the ammeter. The starting circuit connects to the
opposite side of the ammeter.

Never operate the alternator without the battery in the circuit. Making or breaking an
alternator connection with heavy load on the circuit can cause damage to the regulator.

Charging System Components

Alternator (4N3986, 4N3987, 5N5692, 7G7889, 3T6352, 7N9720, 3E7577, 3E7892)

Alternator (4N3986, 4N3987)

(1) Rectifier. (2) Rotor assembly. (3) Stator winding. (4) Coil and support assembly. (5) Ball bearing. (6) Regulator. (7) Roller bearing. (8)
Fan.

Alternator (5N5692, 7G7889, 3T6352)

(1) Regulator. (2) Roller bearing. (3) Stator winding. (4) Ball bearing. (5) Rectifier bridge. (6) Field winding. (7) Rotor assembly. (8) Fan.

Alternator (Typical Illustration) (7N9720, 3E7577, 3E7892)

(1) Fan. (2) Stator winding. (3) Field winding. (4) Regulator. (5) Ball bearing. (6) Roller bearing. (7) Rotor. (8) Rectifier assembly.

The alternator is driven by belts from the crankshaft pulley. This alternator is a three phase, self-rectifying charging unit, and the regulator
is part of the alternator. The alternators (4N3986, 4N3987, 7G7889) have a 60 amp output. The alternator (5N5692) has a 45 amp output.
The alternator (3T6352, 7N9720) has a 35 amp output. The alternator (3E7577) has a 75 amp output. The alternator (3E7892) has a 85 amp
output.

This alternator design has no need for slip rings or brushes, and the only part that has movement is the rotor assembly. All conductors that
carry current are stationary. The conductors are the field winding, stator windings, six rectifying diodes and the regulator circuit
components.

The rotor assembly has many magnetic poles like fingers with air space between each opposite pole. The poles have residual magnetism
(like permanent magnets) that produce a small amount of magnetic lines of force (magnetic field) between the poles. As the rotor assembly
begins to turn between the field winding and the stator windings, a small amount of alternating current (AC) is produced in the stator
windings from the small magnetic lines of force made by the residual magnetism of the poles. This AC current is changed to direct current
(DC) when it passes through the diodes of the rectifier bridge. Most of this current goes to charge the battery and to supply the low
amperage circuit, and the remainder is sent on to the field windings. The DC current flow through the field windings (wires around an iron
core) now increases the strength of the magnetic lines of force. These stronger lines of force now increase the amount of AC current
produced in the stator windings. The increased speed of the rotor assembly also increases the current and voltage output of the alternator.

Alternator (6T1395, 9G4574, 9X7803)

Alternator (Typical Illustration)

(1) Rotor assembly. (2) Stator assembly. (3) Brush assembly. (4) Regulator. (5) Bearings. (6) Capacitor. (7) Slip rings.

The alternator is driven by belts from the crankshaft pulley. The alternator is a 24 volt, (6T1395, 9G4574) 35 ampere (9X7803) 100 ampere
unit with a regulator which is a solid state (transistor, stationary parts) electronic switch installed on the side opposite the pulley. The
alternator is made up of a head assembly on the drive end, rotor assembly, stator assembly, rectifier and heat removal assemblies, brush and
holder assembly, head assembly on the ring end and regulator.

The rotor assembly has the field windings (wires around an iron core) which make magnetic lines of force when direct current (DC) flows
through them. As the rotor turns, the magnetic lines of force are broken by the stator. This makes an alternating current (AC) in the stator.
The rectifier has diodes which change the alternating current (AC) from the stator to direct current (DC). Most of the direct current (DC)
goes to charge the battery and make a supply of direct current (DC) for the low amperage circuit. The remainder of the direct current (DC)
is sent to the field windings through the brushes.

Alternator Regulator (7T5665, 3T6354, 6T9445)

The voltage regulator is a solid state (transistor, stationary parts) electronic switch. It feels the voltage in the system and switches on and
off many times a second to control the field current (DC current to the field windings) for the alternator to make the needed voltage output.

Starting System Components

Solenoid

A solenoid is an electromagnetic switch that does two basic operations:

a. Closes the high current starting motor circuit with a low current start switch circuit.

b. Engages the starting motor pinion with the ring gear.

Typical Solenoid Schematic

The solenoid has windings (one or two sets) around a hollow cylinder. There is a plunger (core) with a spring load inside the cylinder that
can move forward and backward. When the start switch is closed and electricity is sent through the windings, a magnetic field is made that
pulls the plunger forward in the cylinder.

This moves the shift lever (connected to the rear of the plunger) to engage the pinion drive gear with the ring gear. The front end of the
plunger then makes contact across the battery and motor terminals of the solenoid, and the starting motor begins to turn the flywheel of the
engine.

When the start switch is opened, current no longer flows through the windings. The spring now pushes the plunger back to the original
position, and, at the same time, moves the pinion gear away from the flywheel.

When two sets of windings in the solenoid are used, they are called the hold-in winding and the pull-in winding. Both have the same
number of turns around the cylinder, but the pull-in winding uses a larger diameter wire to produce a greater magnetic field. When the start
switch is closed, part of the current flows from the battery through the hold-in windings, and the rest flows through the pull-in windings to
motor terminal, then through the motor to ground. When the solenoid is fully activated (connection across battery and motor terminal is
complete), current is shut off through the pull-in windings. Now only the smaller hold-in windings are in operation for the extended period
of time it takes to start the engine. The solenoid will now take less current from the battery, and heat made by the solenoid will be kept at
an acceptable level.

Starting Motor

The starting motor is used to turn the engine flywheel fast enough to get the engine running.
Starting Motor

(1) Field. (2) Solenoid. (3) Clutch. (4) Pinion. (5) Commutator. (6) Brush assembly. (7) Armature.

The starting motor has a solenoid. When the start switch is turned to the START position, the solenoid will be activated electrically. The
solenoid core will now move to push the starting pinion, by a mechanical linkage, to engage with the ring gear on the flywheel of the
engine. The starting pinion will engage with the ring gear before the electric contacts in the solenoid close the circuit between the battery
and the starting motor.

When the circuit between the battery and the starting motor is complete, the pinion will turn the engine flywheel. A clutch gives protection
for the starting motor so that the engine, when it starts to run, can not turn the starting motor too fast. When the start switch is released, the
starting pinion will move away from the flywheel ring gear.

Magnetic Switch

A magnetic switch (relay) is used sometimes for the starter solenoid circuit. Its operation electrically is the same as the solenoid. Its
function is to reduce the current load on the start switch and control current to the starter solenoid.

Other Components

Circuit Breaker

The circuit breaker is a switch that opens the battery circuit if the current in the electrical system goes higher than the rating of the circuit
breaker.

A heat activated metal disc with a contact point makes complete the electric current through the circuit breaker. If the current in the
electrical system gets too high, it causes the metal disc to get hot. This heat causes a distortion of the metal disc which opens the contacts
and breaks the circuit.

Shutoff Solenoid

The rack shutoff solenoid, when activated, moves the shutoff lever in the governor housing which in turn moves the fuel rack to the fuel
closed position. The solenoid is activated by a manual control switch.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Systems Operation
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Air Starting System

The air starting motor is used to turn the engine flywheel fast enough to get the engine running.

Typical Air Starting System

(1) Air start control valve. (2) Air starting motor. (3) Relay valve. (4) Oiler.

The air starting motor (2) can be mounted on either side of the engine. Air is normally contained in a storage tank and the volume of the
tank will determine the length of time the engine flywheel can be turned. The storage tank must hold this volume of air at 1720 kPa (250
psi) when filled.

For engines which do not have heavy loads when starting, the regulator setting is approximately 690 kPa (100 psi). This setting gives a
good relationship between cranking speeds fast enough for easy starting and the length of time the air starting motor can turn the engine
flywheel before the air supply is gone.

If the engine has a heavy load which can not be disconnected during starting, the setting of the air pressure regulating valve needs to be
higher in order to get high enough speed for easy starting.

The air consumption is directly related to speed; the air pressure is related to the effort necessary to turn the engine flywheel. The setting of
the air pressure regulator can be up to 1030 kPa (150 psi) if necessary to get the correct cranking speed for a heavily loaded engine. With
the correct setting, the air starting motor can turn the heavily loaded engine as fast and as long as it can turn a lightly loaded engine.

Other air supplies can be used if they have the correct pressure and volume. For good life of the air starting motor, the supply should be
free of dirt and water. A lubricator with 10W non detergent oil [for temperatures above 0°C (32°F)], or air tool oil [for temperatures below
0°C (32°F)] should be used with the starting system. The maximum pressure for use in the air starting motor is 1030 kPa (150 psi).
Air Starting Motor

(5) Air inlet. (6) Vanes. (7) Rotor. (8) Pinion. (9) Gears. (10) Piston. (11) Piston spring.

The air from the supply goes to relay valve (3). The air start control valve (1) is connected to the line before the relay valve. The flow of air
is stopped by the relay valve until air start control valve (1) is activated. The air from air start control valve goes to piston (10) behind
pinion (8) for the starter. The air pressure on piston (10) puts piston spring (11) in compression and puts pinion (8) in engagement with the
flywheel gear. When the pinion is in engagement, air can go out through another line to relay valve. The air activates relay valve which
opens the supply line to the air starting motor.

The flow of air goes through the oiler (lubricator) (4) where it picks up lubrication for the air starting motor.

The air with lubrication goes into the air motor through air inlet (5). The pressure of the air pushes against vanes (6) in rotor (7), and then
exhausts through the outlet. This turns the rotor which is connected by gears (9) and a drive shaft to pinion (8) which turns the engine
flywheel.

When the engine starts running, the flywheel will start to turn faster than pinion (8). The pinion (8) retracts under this condition. This
prevents damage to the motor, pinion (8) or flywheel gear.

When air start control valve (1) is released, the air pressure and flow to piston (10) behind pinion (8) is stopped, piston spring (11) retracts
pinion (8). Relay valve (3) stops the flow of air to the air starting motor.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Systems Operation
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Power Take-Off Clutch

Power Take-Off Clutch (Typical Illustration)

(1) Ring. (2) Driven discs. (3) Link assemblies. (4) Lever. (5) Key. (6) Collar assembly. (7) Nut. (8) Yoke assembly. (9) Hub. (10) Plates.
(11) Output shaft.

Power take-off clutches (PTOs) are used to send power from the engine to accessory components. For example, a PTO can be used to drive
an air compressor or a water pump.

The PTO is driven by a ring (1) that has spline teeth around the inside diameter. The ring can be connected to the front or rear of the engine
crankshaft by an adapter.

NOTE: On some PTOs located at the rear of the engine, ring (1) is a part of the flywheel.

The spline teeth on the ring engage with the spline teeth on the outside diameter of driven discs (2). When lever (4) is moved to the
ENGAGED position, yoke assembly (8) moves collar assembly (6) in the direction of the engine. The collar assembly is connected to four
link assemblies (3). The action of the link assemblies will hold the faces of driven discs (2), drive plates (10) and hub (9) tight together.
Friction between these faces permits the flow of torque from ring (1), through driven discs (2), to plates (10) and hub (9), Spline teeth on
the inside diameter of the plates drive the hub. The hub is held in position on the output shaft (11) by a taper, nut (7) and key (5).

NOTE: A PTO can have from one to three driven discs (2) with a respective number of plates.

When lever (4) is moved to the NOT ENGAGED position, yoke assembly (8) moves collar assembly (6) to the left. The movement of the
collar assembly will release link assemblies (3). With the link assemblies released there will not be enough friction between the faces of the
clutch assembly to permit a flow of torque.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Testing & Adjusting
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Introduction

NOTE: For Specifications with illustrations, make reference to Specifications for 3408C & 3412C Industrial Engines, SENR1136. If the
Specifications in SENR1136 are not the same as in the Systems Operation, Testing & Adjusting, look at the printing date on the front cover
of each book. Use the Specifications given in the book with the latest date.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Testing & Adjusting
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Troubleshooting

Troubleshooting can be difficult. The Troubleshooting Index gives a list of possible problems. To make a repair to a problem, make
reference to the cause and correction on the pages that follow.

This list of problems, causes, and corrections will only give an indication of where a possible problem can be, and what repairs are needed.
Normally, more or other repair work is needed beyond the recommendations in the list.

Remember that a problem is not normally caused only by one part, but by the relation of one part with other parts. This list is only a guide
and can not give all possible problems and corrections. The service personnel must find the problem and its source, then make the
necessary repairs.

Troubleshooting Problem List

1. Engine Will Not Turn When Start Switch Is On.

2. Engine Will Not Start.

3. Engine Misfires Or Runs Rough.

4. Stall At Low RPM.

5. Sudden Changes In Engine RPM.

6. Not Enough Power.

7. Too Much Vibration.

8. Loud Combustion Noise.

9. Valve Train Noise (Clicking).

10. Oil In Cooling System.

11. Mechanical Noise (Knock) In Engine.

12. Fuel Consumption Too High.

13. Loud Valve Train Noise.

14. Too Much Valve Lash.

15. Valve Rotocoil Or Spring Lock Is Free.

16. Oil At The Exhaust.

17. Little Or No Valve Lash.

18. Engine Has Early Wear.

19. Coolant In Lubrication Oil.

20. Too Much Black Or Gray Smoke.

21. Too Much White Or Blue Smoke.

22. Engine Has Low Oil Pressure.

23. Engine Uses Too Much Lubrication Oil.

24. Engine Coolant Is Too Hot.

25. Exhaust Temperature Is Too High.

26. Starting Motor Does Not Turn.

27. Alternator Gives No Charge.

28. Alternator Charge Rate Is Low Or Not Regular.

29. Alternator Charge Rate Is Too High.

30. Alternator Has Noise.

Troubleshooting Problems

Problem 1: Engine Crankshaft Will Not Turn When Start Switch Is On

Probable Cause:

1. Battery Has Low Output

Make reference to Problem 26.

2. Wires Or Switches Have Defect

Make reference to Problem 26.

3. Starting Motor Solenoid Has A Defect

Make reference to Problem 26.

4. Starting Motor Has A Defect

Make reference to Problem 26.

5. Internal Problem Prevents Engine Crankshaft From Turning

If the crankshaft can not be turned after the driven equipment is disconnected, remove the fuel nozzles and check for fluid in the cylinders
while the crankshaft is turned. If fluid in the cylinders is not the problem, the engine must be disassembled to check for other internal
problems. Some of these internal problems are bearing seizure, piston seizure, wrong pistons installed in the engine, and valves making
contact with pistons.

Problem 2: Engine Will Not Start

Probable Cause:

1. Starting Motor Turns Too Slow

Make reference to Problem 26 and Problem 27.

2. Dirty Fuel Filter

Install new fuel filter.

3. Dirty Or Broken Fuel Lines

Clean or install new fuel lines as necessary.

4. Fuel Transfer Pump

At starting rpm, the minimum fuel pressure from fuel transfer pump must be 35 kPa (5 psi). If fuel pressure is less than 35 kPa (5 psi),
change the fuel filter element. Look for air in the fuel system. If fuel pressure is still low, install a new fuel transfer pump.

5. No Fuel To Cylinders

Put fuel in fuel tank. "Prime" (remove the air and/or low quality fuel) the fuel system.

6. Poor Quality Fuel

Remove the fuel from the fuel tank. Install a new fuel filter element. Put a good grade of clean fuel in the fuel tank. Refer to Diesel Fuels
and Your Engine, SEBD0717.

7. Wrong Fuel Injection Timing

Make adjustment to timing.

Problem 3: Engine Misfires Or Runs Rough

Probable Cause:

1. Fuel Pressure Is Low

Make sure there is fuel in the fuel tank. Look for leaks or bad bends in the fuel line between fuel tank and fuel transfer pump. Look for air
in the fuel system, sticking, binding or defective fuel bypass valve. Check fuel pressure. The outlet pressure of the fuel transfer pump is 230
± 35 kPa (33 ± 5 psi) at full load speed.

If fuel pressure is lower than 140 kPa (20 psi), install a new filter element. If fuel pressure is still low, install a new fuel transfer pump.

2. Air In Fuel System

Find the air leak in the fuel system and correct it. If air is in the fuel system, it will probably get in on the suction side of fuel transfer pump.

3. Leak Or Break In Fuel Line Between Fuel Injection Pump And Fuel Injection Nozzle

Install a new fuel line.

4. Wrong Valve Lash

Make adjustment according to the subject, Valve Lash Setting.

5. Defect In Fuel Injection Nozzle(s) Or Fuel Injection Pump(s)

Run at rpm that causes engine to misfire the most or run the roughest. Then loosen a fuel injection line nut at the valve cover base for each
cylinder, one at a time. Find the cylinder where a loosened fuel line nut does not change the way the engine runs. Test the injection pump
and injection nozzle for that cylinder. Install new parts where needed.

6. Wrong Fuel Injection Timing

Make adjustment to timing.

7. Bent Or Broken Push Rod

Replacement of push rod is necessary.

8. Fuel Has "Cloud Point" Higher Than Atmospheric Temperature ("Cloud Point" = Temperature Which Makes Wax Form In Fuel.)

Drain the fuel tank, lines, and fuel injection pump housing. Change the fuel filter. Fill the tank with fuel which has the correct "cloud point"
and remove the air from the system with the priming pump.

Problem 4: Stall At Low RPM

Probable Cause:

1. Fuel Pressure Is Low

Make sure there is fuel in the fuel tank. Look for leaks or bad bends in the fuel line between fuel tank and fuel transfer pump. Look for air
in the fuel system, sticking, binding or defective fuel bypass valve. Check fuel pressure. The outlet pressure of the fuel transfer pump is 230
± 35 kPa (33 ± 5 psi) at full load speed.

If fuel pressure is lower than 140 kPa (20 psi), install a new filter element. If fuel pressure is still low, install a new fuel transfer pump.

2. Idle RPM Too Low

Make adjustment to governor so idle rpm is the same as given in the TMI (Technical Marketing Information) or Fuel Setting And Related
Information Fiche.

3. Defect In Fuel Injection Nozzle(s)

Install a new fuel injection nozzle(s).

4. Engine Accessories

Check engine accessories for damage and correct adjustment. If necessary, disconnect the accessories and test the engine.

5. Defect In Fuel Injection Pump(s)

Install new parts if needed.

Problem 5: Sudden Changes In Engine Speed (RPM)

Probable Cause:

1. Failure Of Governor Or Fuel Injection Pump

Look for damaged or broken springs, linkage or other parts. Remove the governor. Check for free travel of the fuel racks. Be sure fuel
injection pumps are installed correctly. Check for correct governor spring. Install new parts for those that have damage or defects.

Problem 6: Not Enough Power

Probable Cause:

1. Poor Quality Fuel

Remove the fuel from the fuel tank. Install a new fuel filter element. Put a good grade of clean fuel in the fuel tank.
2. Fuel Pressure Is Low

Make sure there is fuel in the fuel tank. Look for leaks or bad bends in the fuel line between fuel tank and fuel transfer pump. Look for air
in the fuel system, sticking, binding or defective fuel bypass valve. Check fuel pressure. The outlet pressure of the fuel transfer pump is 230
± 35 kPa (33 ± 5 psi) at full load speed.

If fuel pressure is lower than 140 kPa (20 psi), install a new fuel filter element. If fuel pressure is still low, install a new fuel transfer pump.

3. Leaks In Air Inlet System

Check the pressure in the air inlet manifold. Look for restrictions in the air cleaner.

4. Governor Linkage

Make adjustment to get full travel of linkage. Install new parts for those that have damage or defects.

5. Wrong Valve Lash

Make adjustment according to the subject, Valve Lash Setting.

6. Defect In Fuel Injection Nozzle(s) Or Fuel Injection Pump(s)

Run at rpm that causes engine to misfire the most or run the roughest. Then loosen a fuel line nut on the injection pump for each cylinder,
one at a time. Find the cylinder where a loosened fuel line nut does not change the way the engine runs. Test the injection pump and
injection nozzle for that cylinder. Install new parts where needed.

7. Wrong Fuel Injection Timing

Make adjustment to timing.

8. Rack Setting Too Low

Make reference to the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche.

9. Fuel Ratio Control

Control either needs an adjustment or it is damaged and a new control is needed.

10. Turbocharger Has Carbon Deposit Or Other Causes Of Friction

Inspect and repair turbocharger as necessary.

Problem 7: Too Much Vibration

Probable Cause:

1. Loose Bolt Or Nut For Pulley Or Damper

Tighten bolt or nut.

2. Pulley Or Damper Has A Defect

Install a new pulley or damper.

3. Engine Supports Are Loose, Worn, Or Have A Defect

Tighten all bolts that hold engine supports. Install new components if necessary.
4. Engine Misfires Or Runs Rough

Make reference to Problem 3.

5. Fan Blade Not In Balance

Loosen or remove fan belts and operate engine for a short time at the rpm that the vibration was present. If vibration is not still present,
make a replacement of the fan assembly.

Problem 8: Loud Combustion Noise (Sound)

Probable Cause:

1. Poor Quality Fuel

Remove the fuel from the fuel tank. Install a new fuel filter element. Put a good grade of clean fuel in the fuel tank. Refer to Diesel Fuels
and Your Engine, SEBD0717.

2. Defect In Fuel Injection Nozzle(s)

Install new fuel injection valve(s).

3. Defect In Fuel Injection Pump(s)

Install new fuel injection pump(s).

4. Wrong Fuel Injection Timing

Make adjustment to timing.

Problem 9: Valve Train Noise (Clicking)

Probable Cause:

1. Damage To Valve Spring(s), Locks, Or Broken Or Worn Valve Lifter

Install new parts where necessary. Broken locks can cause the valve to get into the cylinder. This will cause much damage.

2. Not Enough Lubrication

Check lubrication in valve compartment. There must be a strong flow of oil at engine high rpm, but only a small flow of oil at low rpm. Oil
passages must be clean, especially those that send oil to the cylinder head.

3. Too Much Valve Lash

Make adjustment according to the subject, Valve Lash Setting.

Problem 10: Oil In Cooling System

Probable Cause:

1. Defect In Core Of Engine Oil Cooler Or Transmission Oil Cooler

Install a new engine oil cooler or transmission oil cooler. Drain and flush cooling system and refill with new coolant.

2. Defect In Spacer Plate Gasket

Install new spacer plate gasket.

3. Failure Of Cylinder Head Gasket

Install a new head gasket.

Problem 11: Mechanical Noise (Knock) In Engine

Probable Cause:

1. Failure Of Bearing For Connecting Rod

Inspect the bearing for the connecting rod and the bearing surface (journal) on the crankshaft. Install new parts where necessary.

2. Damaged Timing Gears

Install new parts where necessary.

3. Damaged Crankshaft

Make replacement of the crankshaft.

4. Defect In Attachment

Repair or install new components.

Problem 12: Fuel Consumption Too High

Probable Cause:

1. Fuel System Leaks

Large changes in fuel consumption may be the result. Inside leaks probably will cause low engine oil pressure and an increase in oil level
in the engine. Tighten loose connections or make a replacement of the component that leaks.

2. Fuel And Combustion Noise (Knock)

Make reference to Problems 3 and 6.

3. Wrong Fuel Injection Timing

Make adjustment to timing.

Problem 13: Loud Valve Train Noise

Probable Cause:

1. Damage To Valve Spring(s)

Make replacement of parts with damage.

2. Damage To Camshaft

Make replacement of parts with damage. Clean engine thoroughly. If replacement of camshaft is made, new valve lifters are also necessary.

3. Damage To Valve Lifter

Clean engine thoroughly. Make a replacement of the damaged valve lifters. Inspect camshaft lobes for damage. Look for valves that do not
move freely. Make an adjustment to valve lash according to the subject, Valve Lash Setting.

4. Damage To Bridge For Valves Or Bridge Dowel

Make a replacement of the bridge and/or bridge dowel, and adjust as necessary.

Problem 14: Too Much Valve Lash

Probable Cause:

1. Not Enough Lubrication

Check lubrication in valve compartment. There must be a strong flow of oil at engine high rpm, but only a small flow at low rpm. Oil
passages must be clean, especially those that send oil to the cylinder head.

2. Rocker Arm Worn At Face That Makes Contact With Bridge

If there is too much wear, install new parts or rocker arms. Make adjustment of valve lash according to the subject, Valve Lash Setting.

3. Bridge Or Bridge Dowel For Valves Worn

Make replacement of the bridge and/or bridge dowel, and adjust as necessary.

4. End Of Valve Stem Worn

If there is too much wear, install new valves. Make adjustment to valve lash according to the subject, Valve Lash Setting.

5. Worn Push Rods

If there is too much wear, install new push rods. Make adjustment of valve lash according to the subject, Valve Lash Setting.

6. Broken Or Worn Valve Lifters

Install new valve lifters. Check camshaft for wear. Check for free movement of valves or bent valve stem. Clean engine thoroughly. Make
adjustment of valve lash according to the subject, Valve Lash Setting.

7. Worn Camshaft Lobes

Install a new camshaft. Install new valve lifters if damaged. Check for free movement of valves or bent valve stems. Make adjustment of
valve lash according to the subject, Valve Lash Setting.

Problem 15: Valve Rotocoil Or Spring Lock Is Free

Probable Cause:

1. Broken Locks

Broken locks can cause the valve to get into the cylinder. This will cause much damage.

2. Broken Valve Spring(s)

Install new valve spring(s).

3. Broken Valve

Replace valve and other damaged parts.

Problem 16: Oil At The Exhaust

Probable Cause:

1. Too Much Oil In The Valve Compartment

Look at both ends of the rocker arm shaft. Be sure a plug is in each end of the shaft.

2. Worn Valve Guides

Reconditioning of the cylinder head is needed.

3. Worn Piston Rings

Inspect and install new parts as needed.

Problem 17: Little Or No Valve Lash

Probable Cause:

1. Worn Valve Seat Or Face Of Valve

Reconditioning of cylinder head is needed. Make adjustment of valve lash according to the subject, Valve Lash Setting.

Problem 18: Engine Has Early Wear

Probable Cause:

1. Dirt In Lubrication Oil

Remove dirty lubrication oil. Install new engine oil filter elements. Put clean oil in the engine.

2. Air Inlet Leaks

Inspect all gaskets and connections. Make repairs if leaks are found.

3. Fuel Leakage Into Lubrication Oil

This will cause high fuel consumption and low engine oil pressure. Make repairs if leaks are found. Install new parts where needed.

Problem 19: Coolant In Lubrication Oil

Probable Cause:

1. Failure Of Engine Oil Cooler Core

Install a new engine oil cooler. Drain crankcase and refill with clean engine oil. Install new engine oil filter elements.

2. Failure Of Cylinder Head Gasket Or Water Seals

Check cylinder liner projection. Install a new spacer plate gasket and new water seals in the spacer plate. Install a new cylinder head gasket.
Tighten the bolts that hold the cylinder head. Refer to Specifications, 3408C & 3412C Industrial Engines, SENR1136 for the proper
procedure to tighten the cylinder head bolts.

3. Crack Or Defect In Cylinder Head

Install a new cylinder head.

4. Crack Or Defect In Cylinder Block

Install a new cylinder block.

5. Failure Of Liner Seals

Replace seals.

6. Crack Or Defect In Cartridge Of Turbocharger

Install a new turbocharger cartridge.

Problem 20: Too Much Black Or Gray Smoke

Probable Cause:

1. Not Enough Air For Combustion

Check air cleaner for restrictions.

2. Damaged Fuel Injection Nozzle(s)

Install new fuel injection nozzle(s).

3. Wrong Fuel Injection Timing

Make adjustment to timing.

4. Defect In Fuel Ratio Control

Make adjustment to or install new control.

Problem 21: Too Much White Or Blue Smoke

Probable Cause:

1. Too Much Lubrication Oil In Engine

Remove extra oil. Find where extra oil comes from. Put correct amount of oil in engine.

2. Engine Misfires Or Runs Rough

Make reference to Problem 3.

3. Wrong Fuel Injection Timing

Make adjustment to timing.

4. Worn Valve Guides

Reconditioning of cylinder head is necessary.

5. Worn Piston Rings

Install new piston rings. Check condition of cylinder liners.

6. Failure Of Turbocharger Oil Seal

Check inlet manifold for oil. Replace seals and repair turbocharger if necessary.

7. Coolant In Combustion System

Check for cracked head.

Problem 22: Engine Has Low Oil Pressure

Probable Cause:

1. Dirty Engine Oil Filter Or Engine Oil Cooler

Check the operation of bypass valve for the filter. Install new engine oil filter elements if needed. Clean or install new engine oil cooler
core. Remove dirty oil from engine. Put clean oil in engine.

2. Diesel Fuel In Lubrication Oil

Find the place where diesel fuel gets into the lubrication oil. Make repairs as needed. Remove the lubrication oil that has diesel fuel in it.
Install new engine oil filter elements. Put clean oil in the engine.

3. Too Much Clearance Between Rocker Arm Shaft and Rocker Arms

Check lubrication in valve compartment. Install new parts as necessary.

4. Engine Oil Pump Suction Pipe Has A Defect

Replacement of pipe is necessary.

5. Relief Valve For Engine Oil Pump Does Not Operate Correctly

Clean valve and housing. Install new parts as necessary.

6. Engine Oil Pump Is Worn Or Has A Defect

Repair or make replacement of necessary parts.

7. Too Much Clearance Between Crankshaft And Crankshaft Bearings

Inspect crankshaft and bearings. Install new parts as necessary.

8. Too Much Clearance Between Camshaft And Camshaft Bearings

Install new camshaft bearings. Install new camshaft if necessary.

9. Defect In Oil Pressure Indicator

Install new indicator.

10. Too Much Bearing Clearance For Idler Gear

Inspect bearings and make replacement as necessary.

Problem 23: Engine Uses Too Much Lubrication Oil

Probable Cause:
1. Too Much Lubrication Oil In Engine

Remove extra oil. Find where extra oil comes from. Put correct amount of oil in engine.

2. Oil Leaks

Find all oil leaks. Make repairs as necessary.

3. Oil Temperature Is Too High

Check operation of engine oil cooler. Clean the core of the engine oil cooler. Install new parts if necessary.

4. Too Much Oil In The Valve Compartment

Look at both ends of the rocker arm shaft. Be sure a plug is in each end of the shaft.

5. Worn Valve Guides

Reconditioning of the cylinder head is necessary.

6. Worn Piston Rings And Cylinders

Inspect and install new parts as necessary. Reconditioning of the cylinder block may be necessary.

7. Failure Of Seal Rings In Turbocharger

Check inlet manifold for oil and make repair to turbocharger if necessary.

Problem 24: Engine Coolant Is Too Hot

Probable Cause:

1. Restriction To Flow Of Coolant Through Radiator Core Tubes

Clean and flush radiator.

2. Restriction To Air Flow Through Radiator

Remove all restrictions to air flow.

3. Low Fan Speed

Check for worn or loose fan belts.

4. Not Enough Coolant In System

Add coolant to cooling system.

5. Pressure Relief Valve Has A Defect

Check operation of pressure relief valve. Install a new pressure relief valve if necessary.

6. Combustion Gases In Coolant

Find out where gases get into the cooling system. Make repairs as necessary.
7. Water Temperature Regulators (Thermostats) Or Temperature Indicators Have A Defect

Check water temperature regulators for correct operation. Check temperature indicator operation. Install new parts as necessary.

8. Water Pump Has A Defect

Make repairs or replacement of the water pump as necessary.

9. Too Much Load On The System

Make a reduction to the load.

10. Wrong Fuel Injection Timing

Make adjustment to timing.

11. Torque Converter Or Transmission Does Not Operate Correctly. This Can Cause An Increase In The Coolant Temperature

Make corrections for torque converter or transmission running too hot.

Problem 25: Exhaust Temperature Is Too High

Probable Cause:

1. Air Inlet Or Exhaust System Has A Restriction

Remove restriction.

2. Wrong Fuel Injection Timing

Make an adjustment to the timing.

Problem 26: Starting Motor Does Not Turn

Probable Cause:

1. Battery Has Low Output

Check condition of battery. Charge battery or make replacement as necessary.

2. Wires Or Switch Has Defect

Make repairs or replacement as necessary.

3. Starting Motor Solenoid Has A Defect

Install a new solenoid.

4. Starting Motor Has A Defect

Make repair or replacement of starting motor.

Problem 27: Alternator Gives No Charge

Probable Cause:
1. Loose Drive Belt For Alternator

Make an adjustment to put the correct tension on the drive belt.

2. Charging Or Ground Return Circuit Or Battery Connections Have A Defect

Inspect all cables and connections. Clean and tighten all connections. Make replacement of parts with defect.

3. Rotor (Field Coil) Has A Defect

Install a new rotor.

Problem 28: Alternator Charge Rate Is Low Or Not Regular

Probable Cause:

1. Loose Drive Belt For Alternator

Make an adjustment to put the correct tension on the drive belt.

2. Charging Or Ground Return Circuit Or Battery Connections Have A Defect

Inspect all cables and connections. Clean and tighten all connections. Make replacement of parts with defect.

3. Alternator Regulator Has A Defect

Install a new alternator regulator.

4. Rectifier Diodes Have A Defect

Make replacement of rectifier diode that has a defect.

5. Rotor (Field Coil) Has A Defect

Install a new rotor.

Problem 29: Alternator Charge Rate Is Too High

Probable Cause:

1. Alternator Or Alternator Regulator Has Loose Connections

Tighten all connections to alternator or alternator regulator.

2. Alternator Regulator Has A Defect

Install a new alternator regulator.

Problem 30: Alternator Has Noise

Probable Cause:

1. Drive Belt For Alternator Is Worn Or Has A Defect

Install a new drive belt for the alternator.

2. Loose Alternator Drive Pulley

Check groove in pulley for key that holds pulley in place. If groove is worn, install a new pulley. Tighten pulley nut according to
Specifications, 3408C & 3412C Industrial Engines, SENR1136.

3. Drive Belt And Drive Pulley For Alternator Are Not In Alignment

Make an adjustment to put drive belt and drive pulley in correct alignment.

4. Worn Alternator Bearings

Install new bearings in the alternator.

5. Rotor Shaft Is Bent

Make a replacement of the rotor shaft.

6. Rectifiers In The Alternator Are Shorted

Make a replacement of the diode assembly.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Testing & Adjusting
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Fuel System

Either too much fuel or not enough fuel for combustion can be the cause of a problem in the fuel system. Many times work is done on the
fuel system when the problem is really with some other part of the engine. The source of the problem is difficult to find, especially when
smoke comes from the exhaust. Smoke that comes from the exhaust can be caused by a defective fuel injector, but it can also be caused by
one or more of the reasons that follow:

a. Not enough air for good combustion.

b. An overload at high altitude.

c. Oil leakage into combustion chamber.

d. Not enough compression.

e. Fuel injection timing incorrect.

Fuel System Inspection

A problem with the components that send fuel to the engine can cause low fuel pressure. This can decrease engine performance.

1. Check the fuel level in the fuel tank. Look at the cap for the fuel tank to make sure the vent is not filled with dirt.

2. Check the fuel lines for fuel leakage. Be sure the fuel supply line does not have a restriction or a bad bend. Verify that the fuel return line
has not collapsed in the sections subject to heat.

3. Install a new fuel filter. Clean the primary fuel filter.

4. To remove air from the fuel system, use the procedure that follows:

a. Use the priming pump to remove air from the low pressure side of the fuel system.

b. Loosen one-half turn the fuel injection line nuts at each adapter in the valve cover base. Move throttle lever to Low Idle position.
Use the starting motor to turn the engine until fuel without air flows from the loose connections. Tighten the nuts.

NOTE: Because of the check assemblies in the injection pump outlets the priming pump will not give enough pressure to remove air from
the fuel injection lines.

5. Inspect the fuel bypass valve to see that there is no restriction to good operation.

Checking Engine Cylinders Separately

An easy check can be made to find the cylinder that runs rough (misfires) and causes black smoke to come out of the exhaust pipe.

Run the engine at the speed that is the roughest. Loosen the fuel line nut at a fuel injection pump. This will stop the flow of fuel to that
cylinder. Do this for each cylinder until a loosened fuel line is found that makes no difference in engine performance. Be sure to tighten
each fuel line nut after the test, before the next fuel line nut is loosened. Check each cylinder by this method. When a cylinder is found
where the loosened fuel line nut does not make a difference in engine performance, test the injection pump and fuel injection nozzle for that
cylinder.

Temperature of an exhaust manifold port, when the engine runs at low idle speed, can also be an indication of the condition of a fuel
injection nozzle. Low temperature at an exhaust manifold port is an indication of no fuel to the cylinder. This can possibly be an indication
of an fuel injection nozzle with a defect. Extra high temperature at an exhaust manifold port can be an indication of too much fuel to the
cylinder, also caused by an fuel injection nozzle with a defect.

The most common defects found with the fuel injection nozzles are:
1. Carbon on tip of the nozzle or in the nozzle orifice.

2. Orifice wear.

3. Dirty nozzle screen.

Testing Fuel Injection Nozzles

Testing of the fuel injection nozzles must be done off the engine. Perform the following tests using the 5P4150 Nozzle Testing Group to
determine if nozzle performance is acceptable:

Valve Opening Pressure Test

Flush The Nozzle

Tip Leakage Test

Orifice Restriction Test

Bleed Screw Leakage Test

Refer to Special Instruction, SEHS7292, for operation of the 5P4150 Nozzle Testing Group.

Fuel Injection Service

Removal Of Fuel Injection Pump

Put Rack At Zero Position

(1) Governor control shaft. (2) Fuel injection pump housing. (A) 6V6019 Timing Pin.

1. Remove plug from fuel injection pump housing (2).

2. Install 6V6019 Timing Pin (A) with the flat end down in the hole that the plug was removed from.

3. Turn governor control shaft (1) toward High Idle and push down on timing pin (A) until it engages in the slot (groove) in the rack. The
rack is now centered (at zero position). The fuel injection pumps can now be removed.

4. Disconnect the fuel lines from the injection pumps.

5. Use the 8T5287 Wrench to loosen the bushing that holds the fuel injection pump in the housing.

6. Install 8S2244 Extractor (5) on the threads of the injection pump. Pull the pump straight out of the bore.

When injection pumps and spacers are removed from the injection pump housing, keep the parts for each pump together so they can be
installed back in their original location. Make reference to subject, Checking The Plunger And Lifter Washer On The Injection Pump.

Be careful when injection pumps are disassembled. Do not damage the surface on the plunger. The plunger and barrel for each pump are
made as a set. Do not put the plunger of one pump in the barrel of another pump. If one part is worn, install a complete new pump
assembly. Be careful when the plunger is put in the bore of the barrel.

Installation Of Fuel Injection Pump

The fuel rack Must Be In The Center Position before the correct installation of an
injection pump is possible.

The procedure to center the fuel rack is shown in the subject, Removal Of Fuel Injection Pump.

To install a fuel injection pump back into the housing bore, use the procedure that follows:
Fuel Pump Installation

(Typical Illustration) (3) Barrel. (4) Gear segment. (5) 8S2244 Extractor. (6) Bushing.

1. Put 8S2244 Extractor (5) on threads of injection pump.

2. Put groove of barrel (3) in alignment with slot of gear segment (4) (slot is on opposite side of gear segment teeth).

3. Look inside the bore of the injection pump housing to find the dowel. Put groove of the barrel in alignment with the dowel and put the
injection pump straight down into the bore.

4. Push down on 8S2244 Extractor (5) (hand force only) and install bushing (6) that holds the injection pump in the pump housing. If the
pump is in the correct position, the bushing will turn into the threads of the injection pump housing with the fingers until it is even with the
top of the housing (except for the pump that is in the position to fire).

When bushing is installed correctly, tighten the bushing to 163 ± 14 N·m (120 ± 10 lb ft).

Damage to the housing will be the result if the bushing is too tight. If the bushing is not
tight enough, the pump will have leakage.

5. Remove the 6V6019 Timing Pin from injection pump housing and install the plug back in the hole.

6. Move the governor control back to shutoff position. Check to be sure governor control moves freely between fuel-on and shutoff
position.

Check for the correct installation of injection pump with the engine stopped. Rack travel from the center position in the fuel-on direction
can be checked with governor installed, but the governor and governor piston must be removed to check for full rack travel. Use 6V9128
Rack Position Tool Group and the chart that follows to check rack travel. Make reference to Fuel Rack Setting for installation of 6V9128
Rack Position Tool Group.
With the governor piston and valve removed, the total amount of fuel rack travel (from shutoff position to full load position) is
approximately 20.32 mm (.800 in). If the pump is installed wrong (center tooth of gear segment is not in correct notch of fuel rack) fuel
rack travel will be less than 20.32 mm (.800 in). The injection pump will have to be removed and then installed correctly.

If one or more of the fuel injection pumps have been installed wrong, it is possible for
the engine to run out of control when started. When any of the fuel injection pumps
have been removed and installed with the fuel injection pump housing on the engine,
take the precautions (steps) that follow to stop the engine if it starts to overspeed (run
out of control).

Turbocharger With Open Air Inlet

(7) Air inlet.

a. Remove the air cleaner so that turbocharger air inlet (7) is open as shown.
Stopping The Engine

b. If a pump has been installed wrong and the engine does not run in a normal way, put a steel plate over the air inlet opening as shown to
stop the engine.

Checking The Plunger And Lifter Washer On An Injection Pump

Check timing dimension for the fuel injection pumps. Make an adjustment if necessary, with the pump housing off the engine. When an
adjustment to the timing dimension is done correctly, fuel injection in the cylinder will be at the correct time. If the timing dimension is too
small, fuel injection will be early. If the timing dimension is too large, fuel injection will be late.

An injection pump can have a good fuel flow coming from it but not be a good pump because of slow timing that is caused by wear on the
bottom end of the plunger. When making a test on a pump that has been used for a long time, use a micrometer and measure the length of
the plunger. If the length of the plunger is shorter than the minimum length (worn) dimension given in the chart, install a new pump.

Look for wear at the top part of the plunger. Check the operation of the plunger according to the instructions for the Fuel Injection Test
Bench.
Wear Between Lifter Washer And Plunger

Fig.A shows the contact surfaces of a new pump plunger and a new lifter washer. In Fig.B the pump plunger and lifter washer have worn a
large amount. Fig.C shows how the flat end of a new plunger makes bad contact with a worn lifter washer, causing rapid wear to both parts.

When there is too much wear on the pump plunger, the lifter washer may also be worn and there will not be good contact between the two
parts. To stop fast wear on the end of a new plunger, install new lifters in the place of lifters that have washers with wear.

Fuel Injection Lines

Fuel from the fuel injection pumps is sent through the fuel injection lines to the fuel injection nozzle.

Each fuel injection line of an engine has a special design and must be installed in a certain location. When fuel injection lines are removed
from an engine, put identification marks or tags on the fuel lines as they are removed, so they can be put in the correct location when they
are installed.

The nuts that hold a fuel injection line to an injection nozzle and injection pump must be kept tight. Use a torque wrench and the 2P5494
Crow Foot Wrench to tighten the fuel line nuts to 40 ± 7 N·m (30 ± 5 lb ft).

Fuel Bypass Valve

The fuel bypass valve controls fuel pressure to the fuel injection pump at full speed to a pressure of 230 ± 35 kPa (33 ± 5 psi).

Finding Top Center Compression Position For No. 1 Piston

NOTE: No. 1 piston at top center (TC) on the compression stroke is the starting point for all timing procedures.
Locating Top Center (Right Side Of Engine)

(1) Timing bolt (in storage location). (2) Plug. (3) Bolt. (4) Cover.

1. Remove timing bolt (1), bolt (3) and cover (4).

2. Remove plug (2).

Location For 9S9082 Engine Turning Tool

(1) Timing bolt installed. (5) 9S9082 Engine Turning Tool.

3. Install 9S9082 Engine Turning Tool (5) in the housing.

4. Hold timing bolt (1) against the flywheel through the hole from which plug (2) was removed.

5. Use a 1/2 inch drive ratchet and 9S9082 Engine Turning Tool (5) to turn the flywheel counterclockwise (as seen from the rear of the
engine). Stop when the timing bolt goes into a threaded hole in the flywheel. If the timing bolt can be turned freely in the threaded hole in
the flywheel, the No. 1 piston of the engine is on top center.

NOTE: If the hole in the flywheel is turned beyond the hole in the flywheel housing, turn the flywheel back (clockwise) a minimum of 30
degrees. Do Step 5 again. This will prevent timing error caused by play in the timing gears.
3408C Cylinder And Valve Location

3412C Cylinder And Valve Location

6. Remove the left front valve cover. Look at the valves of No. 1 cylinder. All the valves (inlet and exhaust) will be closed if No. 1 piston is
on the compression stroke. You should be able to move the rocker arms up and down with your hand. If No. 1 piston is not on the
compression stroke, do the steps that follow.

7. Remove the timing bolt from the flywheel.

8. Turn the flywheel 360 degrees counterclockwise and install the timing bolt.

NOTE: If the hole in the flywheel is turned beyond the hole in the flywheel housing, turn the flywheel back (clockwise) a minimum of 30
degrees. Do Step 5 again. This will prevent timing error caused by play in the timing gears.
Checking Engine Timing And Automatic Timing Advance Unit With 8T5300 Timing Indicator Group And 8T5301 Diesel Timing
Adapter Group

8T5300 Timing Indicator Group

(1) 8T5250 Engine Timing Indicator. (2) 5P7366 Cable Assembly. (3) 6V2197 Magnetic Transducer. (4) 5P7362 Cable. (5) 6V2199 &
6V3093 Transducer Adapters. (6) 8K4644 Fuse.

The 8T5300 Timing Indicator Group with an 8T5301 Diesel Timing Adapter Group, can be used to measure fuel injection timing for the
engine.

8T5301 Diesel Timing Adapter Group

(7) 5P7437 Adapter. (8) 6V2198 Cable. (9) 5P7436 Adapter. (10) 6V7910 Transducer. (11) 5P7435 Adapter. (12) 6V3016 Washer.

When checking the dynamic timing on an engine that has a mechanical advance, Caterpillar recommends that a service technician calculate
and plot the dynamic timing specifications first on a worksheet like SEHS8140. See Special Instruction, SEHS8580 for information
required to calculate the timing curve. For the correct timing specifications to use, see the Engine Information Plate for the performance
specification number and make reference to the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche.

NOTE: For more information on acceptable tolerances for dynamic fuel injection timing, see Service Magazine dated 4-1-85 and 10-25-
85.

After the timing values are calculated and plotted, the dynamic timing should be checked with the 8T5300 Engine Timing Indicator Group.
The engine must be operated from 1000 rpm (base rpm) to high idle and from high idle to 1000 rpm (base rpm). Unstable readings are
often obtained below 1000 rpm. Record the dynamic timing at each 100 rpm and at the specified speeds during both acceleration and
deceleration. Plot the results on the worksheet.
Inspection of the plotted values will show if the fuel injection timing is within specification and if it is advancing correctly.

1. Make reference to Special Instructions, SEHS8580 for complete instructions and calibration of the 8T5300 Timing Indicator Group.

The engine must be stopped before the timing indicator group is installed. A high
pressure fuel line must be disconnected and a probe must be installed in the flywheel
housing.

Transducer In Position

(10) 6V7910 Transducer. (13) Fuel injection line (for No. 1 cylinder).

2. Disconnect fuel injection line (13) for No. 1 cylinder. Slide the nut up and out of the way. Put 5P7436 Adapter (9) in its place and turn
the adapter onto the fuel pump bonnet until the top of the bonnet threads are approximately even with the bottom of the "window" in
5P7436 Adapter (9).

3. Put 5P7435 Tee Adapter (11) on 6V7910 Transducer (10) and put the end of 5P7435 Tee Adapter (11) in the "window" of 5P7436
Adapter (9).

4. Move the end of fuel injection line (13) down on top of 5P7435 Tee Adapter (11). Hold fuel injection line (13) in place with 5P7437
Adapter (7) and tighten to a torque of 40 N·m (30 lb ft).

Timing Hole Location

(14) Plug.

5. Remove the plug (14) from the timing hole in the flywheel housing. Install the 6V2199 or the 6V3093 Transducer Adapter (5) into the
timing hole. Tighten the transducer adapter firmly finger tight.
Transducer In Position

(3) 6V2197 Magnetic Transducer.

6. Push the 6V2197 Magnetic Transducer (3) into the 6V2199 or the 6V3093 Transducer Adapter (5) until the magnetic transducer makes
contact with the flywheel. Then, pull the magnetic transducer a distance of 1.5 mm (.06 in). Tighten the knurled locknut finger tight.

7. Connect the cables from the transducer to the engine timing indicator (1). Calibrate and make adjustments. Refer to Special Instruction
SEHS8580 for the calibration procedure.

8. Start the engine. Run the engine until the engine temperature reaches the normal operating temperature. Then, run the engine at
approximately one half throttle for eight to ten minutes before measuring the timing.

9. Run the engine at the rpm required to check low idle, high idle, and the automatic timing advance. Record the engine timing indicator
readings.

If the engine timing is not correct, make reference to Fuel System Adjustments: On Engine, Camshaft Timing For Fuel Injection Pump for
static adjustment of the fuel injection pump drive.

10. If the timing advance is not correct, or if the operation of the advance is not even, repair or replace the automatic timing advance. The
automatic timing advance cannot be adjusted.

Fuel System Adjustments: On Engine

Camshaft Timing For The Fuel Injection Pump

1. Put No. 1 piston at top center (TC) on the compression stroke. Refer to Finding Top Center Compression Position For No. 1 Piston.

NOTE: A 1P3566 9/16 Hex Bit cut to a length of 25 mm (1.0 in) can be used to remove the plug from the front end of the fuel injection
pump housing.
Timing Pin Installed

(A) 6V6019 Timing Pin.

2. Remove the plug at the front end of the fuel injection pump housing.

3. Insert the tapered end of the 6V6019 Timing Pin (A) through the hole in the fuel injection pump housing.

4. If the timing is correct, the timing pin will go into the notch in the camshaft and the timing bolt will turn into the threaded hole in the
flywheel. If the timing is not correct, the timing must be changed.

NOTE: If the timing is correct, remove the timing pin and the timing bolt.

Access Cover To Automatic Timing Advance Assembly

(1) Cover.

If the timing is not correct, remove the timing pin. Use the following procedure in order to change the timing:

a. Remove access cover (1) to the four bolts of the automatic timing advance unit.

Automatic Timing Advance Unit

(2) Bolts. (3) Automatic timing advance unit. (4) Retainer.

b. Be sure that the timing pin is removed before you loosen the bolts. Loosen the four bolts (2) which hold automatic timing advance (3) on
the fuel injectio pump camshaft.

c. Tighten the bolts (2) with your fingers until there is resistance to turning the bolts. The retainer (4) should push firmly against the
automatic timing advance (3). This force will hold the automatic timeing advance against the timing gears which prevents play (backlash)
when the gears are turned to the correct position.

d. Remove the timing bolt. Turn the flywheel until the timing pin will go into the groove in the fuel injection pump camshaft.

e. With the timing pin installed, turn the flywheel clockwise (opposite the direction of normal engine rotation) a minimum of 30 degrees.
This step ensures that the play (backlash) is removed from the timing gears when the engine is put on top center (TC).

f. Turn the flywheel in the direction of normal engine rotation until the No. 1 piston of the engine is on the top center of the compression
stroke. Turn the timing bolt into the threaded hole in the flywheel.

g. Tighten the bolts (2) to a torque of 25 N·m (20 lb ft). Remove the timing pin from the fuel injection pump housing.

h. Tighten the bolts (2) to a torque of 136 ± 7 N·m (100 ± 5 lb ft). Then remove the timing bolt from the flywheel.

5. Turn the crankshaft two complete revolutions. Check the timing again to see that timing pin will go into the notch in the camshaft with
the bolt in the flywheel.

6. If the timing is not correct, repeat Steps b thru h.

NOTE: If the timing is correct, remove the timing pin and the timing bolt.

Measuring Fuel Injection Pump Timing Dimension

1. Put No. 1 piston at top center (TC) on the compression stroke. Refer to Finding Top Center Compression Position For No. 1 Piston.

2. Remove the plug at the front end of the fuel injection pump housing.
Timing Pin Installed

(A) 6V6019 Timing Pin.

3. Insert the tapered end of the 6V6019 Timing Pin (A) through the hole in the fuel injection pump housing. The timing pin must fit into the
notch in the fuel pump camshaft.

NOTE: If No. 1 piston is at top center of compression stroke and the 6V6019 Timing Pin does not fit in the notch in the pump camshaft,
refer to Camshaft Timing For The Fuel Injection Pump.

4. Before any fuel injection pump can be removed, the fuel racks must be put in the center position. Refer to Removal Of Fuel Injection
Pump.

Tooling Setup For Measuring The Timing Dimension

(1) 8S3158 Dial Indicator. (2) 3P1565 Collet. (3) 5P4156 Base. (4) 5P4158 Gauge - 50.8 mm (2.00 in) long. (5) 5P4163 Contact Point,
120.7 mm (4.75 mm) long.
Check The Timing Dimension (Typical Illustration)

(1) 8S3158 Dial Indicator. (3) 5P4156 Base. (4) 5P4158 Gauge.

5. Remove No. 1 fuel injection pump with the 8T5287 Wrench and the 8S2244 Extractor. Put 5P4158 Gauge (4) into the bore in the fuel
injection pump housing.

6. Put 3P1565 Collet (2) and 5P4156 Base (3) on 8S3158 Dial Indicator (1). Put 5P4163 Contact Point (5) on the indicator.

7. Use the following procedure in order to calibrate the dial indicator before measuring the lifter dimension:

a. Put the 101.6 mm (4.00 in) long 5P4157 Indicator on the 5P4159 Indicator Stand.

b. With the contact point in the gauge hole, put the dial indicator and base on top of 5P4157 Gauge.

c. Loosen the screw that locks the dial face. Move the dial face until the large pointer is on zero. Tighten the screw.

d. Make a record of the position of the small pointer. The dial indicator is now calibrated.

NOTE: When the fuel injection pump timing dimension is measured, find the difference between the calibrated reading and the present
reading on the dial face. A dimension of 101.6 mm (4.00 in) must be added to the difference between the indicator readings for the correct
measurement.

8. Install the indicator assembly through the 5P4158 Gauge (4).

9. The ON ENGINE timing dimension using the 8S3158 Dial Indicator (1) is shown in the On Engine Lifter Settings For All 3408 Engines
and the On Engine Lifter Settings For All 3412 Engines tables.

NOTE: If the timing of the fuel system is different than the correct timing dimension given in the On Engine Lifter Settings For All 3408
Engines and the On Engine Lifter Settings For All 3412 Engines tables, and the camshaft timing for the fuel injection pump is correct,
remove the fuel injection pump from the engine in order to measure all lifter settings. Adjust the lifter settings as necessary. Refer to the
following tables in the Fuel Systems Adjustments: Off Engine section of this manual for the correct lifter settings:

· Fuel Injection Pump Off Engine Timing Information For All 3408 Engines
· Fuel Injection Pump Off Engine Timing Information For All 3412 Engines.
10. If the timing dimension is correct, install the No. 1 fuel injection pump into the bore in the pump housing. Refer to the Installation Of
Fuel Injection Pump section of this manual.

Fuel Rack Setting

Governor And Injection Pump Housing

(1) Governor control shaft. (2) Control linkage.

1. Disconnect the governor control linkage (2) so that the governor control shaft (1) can move freely through its full travel.

2. Move the governor control shaft (1) to the shutoff position.

Put Rack At Zero Position

(1) Governor control shaft. (3) Hole. (4) 6V6019 Timing Pin.

3. Remove the plug from hole (3). Insert the 6V6019 Timing Pin (4) in hole (3) with the flat end down.

4. Turn the governor control shaft (1) toward High Idle. Push down on the 6V6019 Timing Pin (4) until the timing pin engages in the slot
(groove) in the rack. The rack is now centered at the zero position.

5. Remove the plug at the rear of the housing.

Check Rack Setting

(5) Brass terminal. (6) Fuel ratio control. (7) 6V3075 Dial Indicator. (8) 8T0500 Circuit Tester.

6. Put the 3P1565 Collet and the 9S8883 Contact Point of the 6V3075 Dial Indicator (7) in the hole at the rear of the housing.

7. Adjust the indicator to "0" (zero). Tighten the nut of the collet to hold the indicator at the zero position.

8. Remove the 6V6019 Timing Pin (4).

9. Connect the clip end of 8T0500 Circuit Tester (8) to the brass terminal (5) on the governor housing. Connect the other end of the tester to
an electrical ground.
Adjustment To The Rack Setting (Typical Example)

(9) 8T9173 Rack Adjusting Tool. (10) Adjustment screw. (11) Locknut. (12) Stop collar.

10. Turn the governor control shaft (1) in the FUEL ON direction until the light in the tester shows the maximum output. Turn the shaft in
the FUEL OFF direction until the test light goes out. Turn the shaft slowly in the FUEL ON direction until the test light has a minimum
light output. In this position, the rack stop collar (12) just starts to make contact with the torque spring.

11. Read the fuel rack setting dimension directly from the dial indicator. Refer to the TMI (Technical Marketing Information) or Fuel
Setting And Related Information Fiche, or look at the Engine Information Plate installed on the engine, in order to find the correct
measurement for the rack setting.

12. If the fuel rack setting requires adjustment, remove the fuel ratio control (if equipped) or the cover from the top of the governor. Use the
8T9173 Rack Adjusting Tool (9) in order to loosen the locknut (11). Turn the adjustment screw (10) in a clockwise direction in order to
decrease the fuel rack setting. Turn the adjustment screw (10) in a counterclockwise direction in order to increase the fuel rack setting.

13. Tighten the locknut (11). Perform Steps 11 and 12 in order to check the correct fuel rack setting.

14. When the fuel rack setting is correct, use the 8T9173 Rack Adjusting Tool (9) to hold the screw (10). Tighten the locknut (11) to a
torque of 12 ± 4 N·m (9 ± 3 lb ft).

15. Install the fuel control on the governor. Connect the governor control linkage. Refer to Fuel Ratio Control Adjustment section of this
manual.

Fuel System Adjustments: Off Engine

Setting Fuel Injection Pump Dimension

The OFF ENGINE setting makes an adjustment for wear of components in the fuel injection pump housing. Adjustment of the fuel
camshaft timing compensates for wear in the timing gears and on the camshaft of the fuel injection pumps.

1. Use the 8T5287 Wrench and the 8S2244 Extractor to remove the injection pumps.
6V4180 Off Engine Lifter Setting Tool Group

(1) 1P7410 Timing Plate. (2) 5P1768 Pointer Assembly. (3) 5P3601 Lifter Setting Adapter. (4) 6V6019 Timing Pin. (5) 2S6160 Washer.
(6) 0S1617 Bolt.

Installation Of The 5P1768 Pointer Assembly

(2) 5P1768 Pointer Assembly. (3) 5P3601 Lifter Setting Adapter. (7) 2A0762 Bolt.

2. Fasten the 5P1768 Pointer Assembly (2) to the fuel injection pump housing with the 2A0762 Bolt (7).

3. Install the 5P3601 Lifter Setting Adapter (3) on the drive end of the fuel injection pump camshaft.

4. Insert the tapered end of the 6V6019 Timing Pin (4) through the timing hole in the pump housing and into the notch in the camshaft.

5. Put the 1P7410 Timing Plate (1) on the 5P3601 Lifter Setting Adapter (3). Install the 2S6160 Washer (5) and the 0S1617 Bolt (6). Do
not tighten the bolt.

6. Turn the 1P7410 Timing Plate (1) until the degree mark on the 1P7410 Timing Plate (1) is aligned with the pointer at zero.

7. Tighten the 0S1617 Bolt (6) to a torque of 25 N·m (20 lb ft).

NOTE: Be sure that the 1P7410 Timing Plate does not move from the degree mark when the bolt is tightened.

8. Remove the 6V6019 Timing Pin (4).

9. Refer to the Fuel Injection Pump Off Engine Timing Information For All 3408 Engines and the Fuel Injection Pump Off Engine Timing
Information For All 3412 Engines tables for the timing plate degrees corresponding to the lifter number being checked. Turn the timing
plate counterclockwise until the degree setting for the lifter being checked is aligned with the pointer.

10. Use the following procedure in order to calibrate the dial indicator before measuring the lifter dimension:

a. Put the 101.6 mm (4.00 in) long 5P4157 Gauge on the 5P4159 Gauge Stand.

b. With contact point in the gauge hole, put the dial indicator and the base on top of the 5P4157 Gauge.

c. Loosen the screw that locks the dial face. Move the dial face until the larger pointer is on zero. Tighten the screw.

d. Record the position of the small pointer. The dial indicator is calibrated.
Tooling Setup For Measuring The Timing Dimension

(8) 8S3158 Dial Indicator. (9) 3P1565 Collet. (10) 5P4156 Base. (11) 5P4158 Gauge - 50.8 mm (2.00 in) long. (12) Spacer. (13) Timing
dimension. (14) 5P4163 Contact Point - 120.7 mm (4.75 in) long.

NOTE: When measurement of the fuel injection pump timing dimension is made, find the difference between the adjustment reading and
the present reading on the dial face. A dimension of 101.6 mm (4.00 in) must be added to the difference in indicator readings for the correct
measurement.

11. The OFF ENGINE timing dimension for adjustment of each lifter is shown in the Fuel Injection Pump Off Engine Timing Information
For All 3408 Engines and the Fuel Injection Pump Off Engine Timing Information For All 3412 Engines tables.
12. The spacer (12) for each fuel injection pump must be selected to get the timing dimension for that fuel injection pump. Refer to the
Spacer Table for the spacer thickness of each spacer part number.

13. Perform another check of all timing dimensions after adjustments have been made.

14. Refer to Installation Of Fuel Injection Pump section of this manual for the correct procedures for the installation of fuel injection pumps
in the housing and for checking the full travel of the fuel racks.

15. After the fuel injection pump is installed on the engine, perform the procedures in Fuel System Adjustments: On Engine for Camshaft
Timing For The Fuel Injection Pump and for Measuring Fuel Injection Pump Timing Dimension.
Engine Speed Measurement

9U7400 Multitach Group

The 9U7400 Multitach Group is used to check the fan speed. Refer to Operator's Manual, NEHS0605, for the operating instructions for this
tool.

Governor Adjustments

A mechanic with training in governor adjustments is the only one to make the adjustment
to the set point rpm.

Engine rpm must be checked with an accurate tachometer. Make reference to Engine Speed Measurement.

Low Idle Adjustment

NOTE: The correct Low Idle rpm is given in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche.

To help prevent an accident caused by parts in rotation, work carefully around an

engine that has been started.

Start the engine and run until the temperature of normal operation is reached. Check low idle rpm with no load on the engine. If an
adjustment is necessary, use the procedure that follows:

1. Remove the sealed cover over the High and Low Idle adjustment screws.

Idle Adjustment

(1) Adjustment screw (for high idle). (2) Adjustment screw (for low idle). (3) Tachometer drive.

2. To adjust the Low Idle rpm, move the governor control to Low Idle position and turn adjustment screw (2). Increase the engine speed
and then return control back to Low Idle position to check the setting again.

3. When governor adjustment is correct, install the cover over the adjustment screws.

When the cover is installed on the governor, the idle adjustment screws fit into holes in the cover. The shape of the holes will not let the
idle adjustment screws turn after the idle adjustment is done and the cover is installed.

4. Install a new wire and seal to the cover bolt.

Checking Set Point (Balance Point)

The engine set point is an adjusted specification and is important to the correct operation of the engine. High idle rpm is NOT an adjusted
specification. Set point (formerly balance point) is full load rpm plus an additional 20 rpm. Set point is the rpm at which the fuel setting
adjustment screw and stop or first torque spring just start to make contact. At this rpm, the fuel setting adjustment screw and stop or first
torque spring still have movement between them. When additional load is put on the engine, the fuel setting adjustment screw and stop or
first torque spring will become stable against each other. Set point is controlled by the fuel setting and the high idle adjustment screw.

9U7400 Multitach Group

The 9U7400 Multitach Group is used to check the set point. Refer to Operator's Manual, NEHS0605, for the operating instructions for this
tool.

NOTE: Do not use the tachometer unless its accuracy is known to be within ± 1 rpm.

If the set point is correct and the high idle speed is within specifications, the fuel system operation of the engine is correct. The set point for
the engine is:

A. At 20 rpm greater than full load speed.

B. The rpm where the fuel setting adjustment screw stop or first torque spring just make contact.

Use the procedure that follows to check the set point. Make reference to Techniques For Loading Engines in Special Instruction
SEHS7050.
1. Connect a tachometer which has good accuracy to the tachometer drive.

Circuit Tester Installed

(1) Brass terminal screw. (2) 8T0500 Circuit Tester.

2. Connect the clip end of the 8T0500 Circuit Tester to the brass terminal screw (1) on the governor housing. Connect the other end of the
tester to a place on the fuel system which is a good ground connection.

Work carefully around an engine that is running. Engine parts that are hot, or parts
that are moving, can cause personal injury.

3. Start the engine.

4. With the engine at normal conditions for operation, run the engine at high idle.

5. Make a record of the speed of the engine at high idle.

6. Add load on the engine slowly until the circuit tester light just comes on (minimum light output). This is the set point.

7. Make a record of the speed (rpm) at the set point.

8. Repeat Step 6 several times to make sure that the reading is correct.

9. Stop the engine. Make a comparison of the records from Steps 5 and 7 with Full Load Speed from the Engine Information Plate. If the
Engine Information Plate is not available, see the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche.
The tolerance for the set point is ± 10 rpm. The tolerance for the high idle rpm is ± 50 rpm in chassis and ± 30 rpm on a bare engine.

If the readings from Steps 5 and 7 are within the tolerance, no adjustment is needed.

NOTE: Engines have the actual Dyno High Idle stamped on the Engine Information Plate. It is possible, in some applications that the high
idle rpm will be less than the actual lower limit. This can be caused by high parasitic loads such as hydraulic pumps, compressors, etc.

Adjusting Set Point (Balance Point)

1. If the set point and the high idle rpm are within tolerance, no adjustment is to be made.

2. If the set point rpm is not correct, remove the sealed cover over the High and Low Idle adjustment screws.
Set Point Adjustment

(1) Adjustment screw (for high idle). (2) Adjustment screw (for low idle). (3) Tachometer drive.

3. Turn adjustment screw (1) to adjust the set point to the midpoint of the tolerance.

4. When the set point is correct, check the high idle rpm. The high idle rpm must not be more than the high limit of the tolerance.

If the high idle rpm is more than the high limit of the tolerance, check the governor spring and flyweights. If the high idle rpm is less than
the low limit of the tolerance, check for excess parasitic loads and then the governor spring and flyweights.

5. When governor adjustment is correct, install the cover over the adjustment screws.

When the cover is installed on the governor, the idle adjustment screws fit into holes in the cover. The shape of the holes will not let the
idle adjustment screws turn after the idle adjustment is done and the cover is installed.

6. Install a new wire and seal to the cover bolt.

Fuel Ratio Control And Governor Check

9U7400 Multitach Group

The 9U7400 Multitach Group is used to check the fuel ratio control and governor. Refer to Operator's Manual, NEHS0605, for the
operating instructions for this tool.

FT1906 Air Test Kit

(1) 8L6557 Connector. (2) 5P4405 Connector (two required). (3) 5P6011 Tube [7.3 m (24 ft)]. (4) 5P4476 Connector. (5) 6K5741 Valve.
(6) 5P4459 Elbow. (7) 7B192 Cross. (8) 3B6768 Bushing. (9) 9S8138 Indicator. (10) 6N3169 Hose Assembly. (11) 6V6757 Elbow. (12)
**6.35 mm (.250 in) I.D. Flexible Tubing [1.2 m (4 ft) long]. (13)* Air pressure bulb.

*Baumamometer No. 1890 or equivalent. Available from medical supply store. Bulb must be equipped with valve.

**Available from medical supply store.

NOTE: The governor seals do not have to be cut or removed for the checking procedures that follow. For more information on the tooling
and procedures see Video Tape LEVN9173 and Special Instruction SEHS8463.
Disconnect Air Line

(14) Air line.

1. Disconnect line (14) from the fuel ratio control and connect FT1906 Air Test Kit between the air inlet manifold and fuel ratio control.

2. Connect the 9U7400 Multitach Group or a circuit testing flashlight to the continuity contact of the governor.

Check Diaphragm Leakage

(5) 6K5741 Valve.

3. Check fuel ratio control diaphragm leakage.

a. Turn tester 6K5741 Valve (5) so manual air pressure can be applied.

b. With the engine shut off, apply 70 kPa (10 psi) air pressure to the fuel ratio control.

c. Close the valve on air pressure bulb (13) and check the leak down rate. Leakage of 20 kPa (3 psi) in 30 seconds is acceptable.

d. If leakage is more than 20 kPa (3 psi) in 30 seconds, check for external leaks and repair. If necessary, install a new diaphragm in
the fuel ratio control and repeat the above steps.

e. When air pressure leakage is acceptable, release all air pressure from the fuel ratio control and proceed to Step 4.

4. Check shutoff linkage and static full fuel rack travel.

a. Turn the ignition switch on, but do not start the engine or move the governor control linkage. Observe the shutoff level or shaft.
Slowly advance the governor control linkage to the full fuel position. Interference exists if there is any movement of the shutoff
lever. If there is interference, check shutoff lever adjustment and linkage alignment.

NOTE: Any contact between the governor control linkage and the shutoff linkage causes power and response problems at high boost when
manifold pressure is greater than 381 mm (15 inches of Hg) or 52.5 kPa (7.5 psi).

b. Move the tooling to the operator's station. Slowly move the governor control linkage to the full fuel position. The lug light or
continuity light should come on before 1/2 full fuel position for most fuel system applications.
If the lug light or continuity light does not come on, check linkage travel for correct adjustment. Check shutoff solenoid adjustment. Check
the operation of the governor circuit indicator. Look for any restrictions in the governor and linkage operation.

If the light turns on, proceed to Step 5.

5. Check dynamic full fuel rack travel. Zero air pressure to the fuel ratio control.

a. Start the engine. Move the governor control linkage to the full fuel position and release it. Repeat this sequence twice. The
continuity light or lug light should come on.

b. If the light does not turn on, the fuel ratio control is activated too early. This can be caused by an incorrect adjustment. Do not
adjust the fuel ratio control at this time. Proceed to Step 7, because the control has already activated.

c. If the light turns on, proceed to Step 6.

6. Check activation of fuel ratio control.

a. Adjust the governor control linkage to maintain 900 plus or minus 100 rpm.

b. Turn tester 6K5741 Valve (5) so that manual air pressure can be supplied and apply 35 kPa (5 psi) for ten seconds and release all
air pressure.

c. Move the governor control linkage to the full fuel position several times. The lug light should not be on. This simulates a low
boost pressure that activates the fuel ratio control. If the light comes on apply 35 kPa (5 psi) again and hold this pressure for ten
seconds. With the 2W8449 Orifice installed or when excessive wear of the housing or seals exist additional time may be required
to activate the fuel ratio control.

d. If the continuity or lug light turns on after Step c, check the continuity circuit to make sure it is operating correctly. Check the
fuel ratio setting and adjust or repair the control as needed.

e. If the continuity or lug light does not turn on, the fuel ratio control is activated and acceptable. Proceed to Step 7.

7. Check full fuel position of the fuel ratio control.

a. Manually apply and hold 25 kPa (4 psi) on the fuel ratio control.

b. Move the governor control linkage to the full fuel position and release it.

c. Increase the air pressure 3.5 kPa (.5 psi) and again move the governor control linkage to the full fuel position and release it.

d. Repeat Step c until the continuity or lug light on the set point indicator turns on. Record this pressure reading. With controls
adjusted to a less restrictive setting, full fuel and a continuity light indication can occur before 25 kPa (4 psi).

NOTE: When the light comes on, the fuel ratio control is extended and the fuel rack has moved to the full fuel position. The fuel ratio
control has additional travel at higher boost pressures than this reading.

8. Load test to compare engine boost and fuel ratio control movement with the results from Step 7.

a. Turn the tester valve to allow manifold boost readings.

b. With engine speed at 1500 rpm and at low boost, 20 kPa (3 psi) or less, quickly load the engine with full load and full fuel.
When the lug or continuity light turns on, record the boost pressure reading. Do this several times to get an accurate reading.

NOTE: An activated light indicates full rack travel. The engine must have a load that requires full fuel. Loads that require less than full
fuel will not give consistent readings.

c. The boost reading should be within plus or minus 3.5 kPa (.5 psi) of the reading obtained in Step 7. Repeat this test sequence
twice. If a full load test is possible, record the set point rpm, maximum boost, and also horsepower if on a dynamometer.
 d. If erratic readings are obtained, either the fuel ratio control, governor or the checking procedure is not operating correctly.

9. Check governor response.

a. Turn the tester valve so that manual air pressure can be applied.

b. Apply 70 kPa (10 psi) or at least 14 kPa (2 psi) air pressure higher that what is recorded from the manual full fuel position check
(Step 7). This moves the fuel ratio control away from the rack control position.

c. While underload, move the governor control linkage to its full fuel position. Make a note of how fast continuity is obtained.

d. If it takes more than two seconds to obtain continuity, governor response is not acceptable. Inspect external attachments on the
governor for interference or, for excessive shutoff lever contact.

e. Stop the engine.

10. If Steps 3 through 9 show the fuel ratio control and governor operation is acceptable, the checking procedure is complete. If repair of
the fuel ratio control or governor is indicated, do the steps that follow for additional troubleshooting.

NOTE: The above checks are used to verify response functions only. The procedures have not checked for correct adjustment of the fuel
ratio control and governor fuel settings.

11. Install the fuel setting and measurement tools from the 6V9128 Rack Position Tool Group. Do not remove the fuel ratio control or
shutoff solenoid.

a. Measure the static full load setting and compare it to the specification on the Engine Information Plate.

NOTE: If the static full load setting is incorrect, continue through Step 15 before any adjustments are made.

12. Measure the static fuel torque setting. Move the governor control linkage to its maximum fuel on position and record the full torque
reading. At this point, the torque spring is compressed and internal governor clearances are at a minimum.

13. Measure the fuel rack setting with the fuel ratio control activated:

a. Start the engine and run it at 900 rpm.

b. Apply 35 kPa (5 psi) air pressure for ten seconds to activate the fuel ratio control. Now, release all air pressure on the fuel ratio
control.

c. Move the governor control linkage to the full fuel on position and release it. Record the dynamic fuel ratio control setting.

14. Check the dynamic full torque setting. (Engine running with no load).

a. Apply and hold 70 kPa (10 psi) air pressure to extend the fuel ratio control to a position beyond the full fuel position.

b. Move the governor control linkage to the full fuel position and release it. Record the dynamic full torque setting.

c. The dynamic full torque setting should be 0.41 to 0.61 mm (.016 to .024 in) more than the static full torque setting measured
in Step 12. This shows the amount of governor servo piston movement which must be 0.41 to 0.61 mm (.016 to .024 in).

d. If the dynamic full torque setting is 0.36 mm (.014 in) or less than the static full torque setting measured in Step 12, the fuel
rack does not have full travel. This indicates there is interference between parts or there are internal governor problems. Also, the
shutoff system can require inspection. Do Step e.

e. With 70 kPa (10 psi) air pressure still on the fuel ratio control, hold the fuel shutoff lever completely out of the way. Move the
governor control linkage to the full fuel position and note the dynamic full torque setting. If the setting increases to the range
given in Step c, then the shutoff lever linkage needs adjustment or repair. If the setting does not change continue to Step 15.
15. Check governor servo and shutoff circuit.

a. With the engine shutdown, remove the fuel ratio control. Install a 4N5656 Cover. Measure the static full torque setting and
compare this setting with the setting measured in Step 12. The two settings must be the same or repair of the fuel ratio control is
needed.

b. Start the engine. Move the governor control linkage to the full fuel position and release it. Record the dynamic full torque
setting and compare the setting with the setting measured in Step 14b.

c. If the dynamic movement is the same as Step 14b, the fuel ratio control is working correctly. If there is more than 0.25 mm (.010
in) difference, check for shutoff interference of internal governor linkage problems.

16. Make any fuel setting adjustments necessary.

NOTE: See Fuel Rack Setting for the correct procedure to install the tooling to make the adjustment.

17. If the governor gives slow response, check for restricted rack movement. Also, check for other governor problems. No specific repair
procedures are available.

NOTE: Response is the engine's ability to accelerate, under load, to its rated horsepower. Low power is the engine's inability to produce
rated horsepower.

Poor response can result from problems with the governor, the fuel ratio control or the shutoff system. Low power can result from problems
with the fuel pump, the governor setting, the shutoff system or the other fuel flow components, or with the engine application.

Fuel Ratio Control Adjustment

1. The fuel rack setting must be correct before the adjustment for the fuel ratio control can be checked. Make reference to Fuel Rack
Setting.

NOTE: The 6V3075 Dial Indicator for fuel rack setting is used for the adjustment of fuel ratio control.

Fuel Ratio Control

(1) Valve. (2) Pin. (3) Cover.

2. Remove cover (3) from the fuel ratio control.

 To help prevent an accident caused by parts in rotation, work carefully around an
engine that has been started.

3. Start the engine.

4. Push the end of valve (1) in and hold it in for two or three seconds. This action will manually move the valve into its operating position.

5. Move the governor control lever in the Fuel On direction, then return it to Low Idle. Do this several times to remove the air from the oil
in the control. This will make the result of the test more accurate.

6. Rapidly move the governor control lever in the Fuel On direction. Read the maximum measurement on the dial indicator. This is the
dynamic fuel ratio control setting. See the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche for the
correct setting.

7. To make an adjustment to the fuel ratio control, turn valve (1) in a clockwise direction to increase the amount of fuel possible (more rack
travel) at the limited rack position. Turn the valve counterclockwise to decrease the amount of fuel possible (less rack travel).

8. After an adjustment is made, do Step 6 again. When the adjustment is correct, put cover (3) on the control. Turn the cover as necessary
to put it in alignment with the nearest bolt holes. Install the bolts.

9. Stop the engine. After the oil pressure has gone out of the fuel ratio control, check the fuel rack setting again to make sure full rack travel
is available.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
Special Instruction
Media Number SEHS7292-10 Publication Date 2002/02/02 Update Date 2002/05/01

Using The 5P-4150 Nozzle Testing Group

0782

Introduction

The 5P-4150 Tester Group is used for testing:

· Capsule-Type Fuel Valves

· Pencil-Type Fuel Nozzles

· Caterpillar Direct Injection Fuel Nozzles

NOTE: The additional tools referenced in this manual are needed for testing or cleaning specific fuel valves and nozzles or are part of
8S-2245 Cleaning Tool Group. These tools are available from the Parts Department.

The 8T-0860 and 8T-0856 Pressure Gauges, 1U-9578 Repair Kit (not shown), 8T-5313 Nozzle Test Filter (1), and 6V-0183 Pump
Body Gasket (2) are all available from the Parts Department.

Install a new 8T-5313 Nozzle Tester Filter (1) at least once every three months, or more often when necessary. Install a new 6V-0183
Pump Body Gasket (2) when necessary.

NOTE: For nozzle cleaning procedure, refer to Special Instruction SEHS8627 entitled "Use Of 8S2245 Nozzle Cleaning Tool Group".

REFERENCE: Service Manual Parts Book, Special Instruction SEHS8627 "Use of 8S2245 Nozzle Cleaning Tool Group",
SEHS7390 "Test Sequence For Pencil-Type Fuel Nozzles".

General Information
NOTE: When testing either new nozzles or nozzles that are not suspected of a failure, it is permissible to flush each nozzle three full
strokes before the test.

It is necessary to have an accurate record of the test results for each nozzle that is tested. Record the results of each nozzle test
procedure on SEHS8144 "Nozzle Test Record".

These test sheets are available through Miscellaneous Order Division. Pads containing 50 sheets may be ordered with special
instruction SEHS8144. A copy of SEHS8144 is shown at the back of this manual.

NOTE: Always keep the reservoir filled with CLEAN calibration fluid. Low oil level will cause SOFT or SPONGY operation of the
tester pump. Use SAE J-967 Calibration Fluid in the tester. Order calibration fluid, according to the amount needed, by the following
part numbers.

6V-6067 Calibration Fluid...208 L (54.9 gal U.S.) Drum

6V-6068 Calibration Fluid...19 L (5.0 gal U.S.) Pail

9U-7411 Calibration Fluid...3.8 L (1.0 gal U.S.) Pail

Have the pressure gauges checked and calibrated at least once each year. Checking and calibration should be performed more often if
the test results become inconsistent of inaccuracy is suspected.

NOTE: There are two methods for gauge calibration. Gauge calibration should be checked using the 5P-8558 Pressure Gauge
Calibrating Group or calibrated by the gauge manufacture.

This manual contains the instructions for gauge calibration when using 5P-8558 Pressure Gauge Calibrating Group. This Manual also
contains the procedures to follow if the gauges are sent to the manufacturer for calibration.

Refer to "Calibration (Method 1 or Method 2)" in this manual.

The rate of 8T-0856 Pressure Gauge is 0-6000 kPa (0-870 psi) with minor divisions (increments) of 100 kPa (20 psi).

The range of 8T-0860 Pressure Gauge is 0-40 000 kPa (0-5800 psi) with minor divisions (increments) of 1000 kPa (100 psi).

The accuracy for either gauge is ± 2.0 percent full scale across the entire readable range.

The test information in this manual has been obtained by comparison tests of fuel nozzles known to be good. These tests are not
intended to be a duplication of conditions that exist during engine operation.

The tests in this manual will provide an indication of nozzle condition. A nozzle that has a defect is NOT always the only cause for a
specific engine problem.

NOTE: The absence of valve chatter or spray during the test does not indicate that the nozzle has a defect. Chatter can occur on the
tester but not occur when the nozzle is installed in the engine.

When testing fuel injection nozzles, always wear eye protection. Fuel sprays from the
orifices in the nozzle tip under high pressure. It can pierce the skin and cause serious
injury to the operator. Always keep the tip of the nozzle pointed away from the
operator and into 8S-2270 Fuel Collector Assembly and FT-1384 or 1U-8857
Extension Tube.

The test procedures for Capsule-Type Fuel Nozzles, Pencil-Type Fuel Nozzles, and Caterpillar 7000 Series Fuel Nozzles are provided
in hits manual. In addition, the test procedures are also available in an abbreviated, chart-type form. The form numbers for these charts
are:

· SEHS7350 "Test Sequence For Capsule-Type Fuel Nozzles"

· SEHS7390 "Test Sequence For Pencil-Type Fuel Nozzles"
· SEHS9083 "Test Sequence For Caterpillar 7000 Series Fuel Nozzles"
Order these publications using the normal literature ordering procedure.

Components Of 5P-4150 Tester Group

Installation Of 5P-4150 Tester Group In Permanent Location
It is possible to get more accurate tests and easier operation if 5P-4150 Tester Group is fastened permanently and securely to a work
bench. This can be performed with bolts or clamps, or with the use of a bracket similar to mounting bracket (1).

There are four holes in the bottom of tester reservoir (2). These holes have 1/4 inch - 20 threads. Use the dimensions shown to locate
and then to drill four holes (A) 7.5 mm (.30 in) at the specific location where the tester will be fastened.

Holes (A) can be drilled in a workbench, a fabricated bracket (1), or any other desired location that is to serve as the permanent
location for the tester. Use the necessary bolts and washers in order to fasten the tester in position.

Service Parts for 5P-8744 Nozzle Adapter Assembly

(1) 5P-4720 Fitting.(2) 5P-8741 Adapter.(3) 5P-8740 Retainer.(4) 5P-8742 Piston.(5) 2S-4663 O-ring Seal.
Use rod (6) or a screwdriver, as shown, to push 5P-8742 Piston (4) out of 5P-8741 Adapter (2).

Replacement Of 5P-4721 Tube

1. Place nuts (1) and sleeves (2) on tube (3).

NOTE: Install each sleeve (2) so longer part (A) of each sleeve is toward each nut (1).

2. Install elbow (4) and fitting (5). Tighten nuts (1) until the threads on elbow (4) and fitting (5) are covered by the nut.

Components Needed That Are Not Part of 5P-4150 Tester Group

(1) FT-1384 or 1U-8857 Extension Tube.(2) 5P-7448 Fuel Valve Adapter (for testing flat seat fuel nozzles).(3) 8S-2270 Fuel Collector
Assembly.(4) 5P-4718 Nozzle Test Adapter Assembly (for testing Perkins fuel nozzles).

Additional Parts Needed to Test 7N-0449 Fuel Injection Nozzle Assembly And Caterpillar 7000 Series Direct Injection Fuel
Nozzles
The parts shown above [6V-2170 Tube Assembly (1), 6V-2171 Tube Assembly (2) and two 5P-7448 Fuel Valve Adapters (3)] are not
part of the tester group but are needed to test some nozzles.

One 6V-2171 Tube Assembly (2) and one 5P-7448 Fuel Valve Adapter (3) are needed to test 7N-0449 Fuel Injection Nozzle
Assembly.

One 6V-2170 Tube Assembly (1) and one 5P-7448 Fuel Valve Adapter (3) are needed to test certain Caterpillar 7000 Series Nozzles.

For some other Caterpillar 7000 Series Nozzles, it will be necessary to use 5P-4244 Nozzle Adapter, 5P-4721 Tube, and Ft-1743 Line
Assembly (none of which are shown here) to perform the test procedure. Specific procedures are given in this manual.

NOTE: The FT-1743 Line Assembly is constructed from 1W-4660 Fuel Injector Line Assembly. See the Tool Guide for FT print
ordering information.

Optional Modification/Installation Of Quick Disconnect Couplings For Nozzle Adapters

Installation and use of the optional quick disconnect couplings on 5P-4150 Tester Group allows for much faster and easier exchange
from one nozzle adapter to another during a test procedure.

The following procedure lists all of the quick disconnect adapter that can be used.

1. Cut off exactly 59 mm (2.3 in) from short end (A) of one 5P-4721 Tube (1). Temporarily place this tube aside. (The 5P-8744
Nozzle Adapter Assembly will be installed on this tube later in the procedure.)

NOTE: The Pressure Loss Specifications for capsule-type fuel nozzles, as shown in this manual, were developed with the use of a
standard (unmodified) 5P-4150 Tester Group.

The shortened tube shown here and new 6V-4143 Coupler Assembly (to be installed later) will provide the correct length for this test.
2. Cut off 75 mm (3.0 in) from long end (B) of one 6V-2170 Tube Assembly (2).

3. Cut off 75 mm (3.0 in) from short end (A) of three additional 5P-4721 Tubes (1) and one 6V-2171 Tube Assembly (3).

4. Remove the burrs from the cut ends. Thoroughly clean the tubes.
5. Install, as shown, 5P-4719 Fitting (4) and 6V-3989 Unvalved Nipple (5) at the cut end of each tube (1), (2), and (3).

6. Use 3J-1906 Nuts (6) with 3J-1905 Fitting Sleeves to install:

· 5P-8744 Nozzle Adapter Assembly (7).

· 5P-7448 Fuel Valve Adapter (8) (at three locations).

· 5P-4718 Nozzle Test Adapter Assembly (9), and

· 5P-4244 Nozzle Adapter (10).
NOTE: Install each 3J-1905 Fitting Sleeve so the longer part of the sleeve is toward nut (6).

7. Remove the original tube assembly and fitting from the tester. Then, install 6V-4143 Coupler Assembly (11) with 5P-3238 Hex
Pipe Reducing Nipple as a replacement.

Testing Capsule-Type Fuel Nozzles For Precombustion Chamber Engines and Direct Injection Engines

Weld shut the orifice of an old capsule-type fuel nozzle. Keep the fuel nozzle with the tester group for future use.

NOTE: DO NOT weld shut the orifice of the nozzles that are to be tested.

Former 5P-4717 Adapter Assembly.

5P-8744 Nozzle Adapter Assembly.

The procedure to use for either of the adapters is the same except where indicated.

NOTE: The 5P-4717 Adapter Assembly is cancelled and has been replaced by 5P-8744 Nozzle Adapter Assembly.

The 5P-4717 Adapter Assembly is shown to illustrate the difference between the two adapters.

NOTE: The 5P-8744 Nozzle Adapter Assembly is the preferred adapter because it permits better test results on capsule-type nozzles.

Install top part (A) of the capsule valve holder.

Position nozzle (1) with the welded shut orifice in bottom part (b) of the valve holder.

Install and tighten bottom part (B) to top part (A).

1. CLOSE On/Off valve (2).

2. OPEN pump isolator valve (3).

3. Pump the tester until a pressure of 24 000 kPa (3500 psi) is attained on the pressure gauge.

CLOSE pump isolator valve (3).

Inspect all connections for leaks. Perform repairs as necessary.

4. Open On/Off valve (2) and remove the fuel nozzle with the welded shut orifice.

Be sure to open On/Off valve (2) before removal of the welded shut fuel nozzle. Fuel
under high pressure can cause injury to the operator of the nozzle tester if the On/Off
valve is not open when bottom part (B) is loosened.

NOTE: The top sealing surface of the welded shut test nozzle and all other nozzles that are to be tested MUST be free of scratches and
burrs (sharp edges).

5. Repeat Step(s) 1-4:

· Each time 5P-8744 Nozzle Adapter Assembly or 5P-4717 Adapter Assembly is removed and then installed again.
· Before and after a series of tests.

· If there is an indication of a problem with the nozzle tester.

Test Sequence For Precombustion Chamber Fuel Nozzles

DO NOT drill or ream the orifice of a nozzle. DO NOT use a steel brush or a wire wheel to
clean the tip of the nozzle because the orifice and valve can easily be damaged. A hand-
held brass brush is acceptable for cleaning the nozzle tip. For nozzle cleaning procedure,
refer to Special Instruction SEHS8627 "use Of 8S-2245 Nozzle Cleaning Tool Group".

Nozzle Installation

1. Place one of the nozzles to be tested in the nozzle holder. Install the nozzle holder and tighten the adapter nut.

2. Close On/Off valve (1).

OPEN gauge protector valve (2) [0-6900 kPa (0-1000 psi) gauge]. Pump isolator valve (3) one-half turn.

Bleed (Remove) Air From Tester

1. Loosen one-half turn bottom part (A) of the adapter.

2. Operate the pump until clear test fluid flows from threads (C) of adapter (B).

NOTE: With 5P-8744 Nozzle Adapter Assembly, pressure may begin to build before clear test fluid appears. If this condition exists,
proceed to Step 3.

3. Tighten bottom part (A) of the adapter.

NOTE: The 5P-8744 Nozzle Adapter Assembly is self-sealing and normally very little turning force is required on bottom part (A) of
the adapter.

Pressure Loss Test

1. OPEN gauge protector valve (2) an additional one-half turn.

2. SLOWLY increase the pressure to 2070 kPa (300 psi). CLOSE pump isolator valve (3).

Again adjust the pressure to 2070 kPa (300 psi) with gauge protector valve (2).

3. After thirty seconds, record the pressure loss.

4. If the pressure loss is NOT within the Pressure Loss Specification, STOP the test sequence.

DO NOT use the nozzle.

Valve Opening Pressure (VOP) Test

1. OPEN pump isolator valve (3) one-half turn.

2. SLOWLY increase the pressure until the test fluid just begins to flow from the nozzle tip. This is valve opening pressure (VOP).

3. If VOP is NOT within the VOP Specification, STOP the test.

DO NOT use the nozzle

NOTE: Spray pattern or atomization tests are not specified for precombustion chamber type fuel nozzles. Such tests do not provide an
accurate indication of a good or defective nozzle.

Test Sequence For Direct Injection Fuel Nozzles

DO NOT drill or ream the orifices of a nozzle. DO NOT use a steel brush or a wire wheel
to clean the tip of the nozzle because the orifices and valve can easily be damaged. The use
of a hand-held brass brush is acceptable for cleaning the nozzle tip. For nozzle cleaning
 procedure, refer to Special Instruction SEHS8627 "Use Of 8S-2245 Nozzle Cleaning Tool
Group".

Nozzle Installation

1. Position the nozzle to be tested in the nozzle holder.

Install the nozzle holder and tighten the adapter nut.

2. CLOSE On/Off valve (1).

OPEN gauge protector valve (2) one-half turn [0-34 470 kPa (0-5000 psi) gauge].

OPEN pump isolator valve (3) one-half turn.

CLOSE gauge protector valve (4).

Bleed (Remove) Air From Tester

1. Loosen one-half turn bottom part (A) of the adapter.

2. Operate the pump until clear test fluid comes from threads (C) of adapter (B).

3. Tighten bottom part (A) of the adapter.

NOTE: The 5P-8744 Nozzle Adapter Assembly is self-sealing and normally very little turning force is required on bottom part (A) of
the adapter.

It may be necessary to use 1P-2853 Spanner Wrench and a 1 1/8 inch open-end wrench to tighten the adapter. This will prevent
excessive leakage from some direct injection fuel nozzles for the 3400 Engines.

Pressure Loss Test

1. OPEN gauge protector valve (2) an additional one-half turn.

2. SLOWLY increase the pressure to 15 170 kPa (2200 psi) and CLOSE pump isolator valve (3).

A loss of pressure to zero (0) AFTER five seconds is acceptable.

NOTE: To assure consistent tests, verify that the tester does not internally leak. Refer to Testing Capsule-Type Fuel Nozzles For
Precombustion Chamber Engines and Direct Injection Engines in this manual.

3. If pressure loss is NOT within the Pressure Loss Specification, STOP the test.

DO NOT use the nozzle.

Valve Opening Pressure (VOP) Test

1. OPEN gauge protector valve (2) one-half turn.

2. SLOWLY increase the pressure until the test fluid flows from the nozzle tip.

3. If VOP is NOT within the VOP Specification, STOP the test.

DO NOT use the nozzle.

Nozzle Flushing Procedure

1. CLOSE gauge protector valve (2).

2. Pump the tester three full strokes.

3. OPEN gauge protector valve (2).

Tip Leakage Test

1. Wipe dry the nozzle tip and adapter. Wrap a clean shop towel around the lower part of the adapter. The towel prevents return
leakage down the outside of the adapter which may give a false tip leakage indication.

2. Increase the pressure to between 3450 kPa (500 psi) and 6900 kPa (1000 psi). Hold this pressure for thirty seconds.
3. If the tip leakage is NOT within the Tip Leakage Specification, STOP the test.

DO NOT use the nozzle.

Spray Pattern Test

1. Rapidly increase the pressure until the nozzle valve opens and the test fluid sprays from the tip.

NOTE: "RAPIDLY increase the pressure" is defined as:

· Each full pump stroke is performed in LESS than one second.

Direct injection capsule nozzles must give an appearance as shown above.

The test fluid must flow from all orifices.

2. Use the 8S-2258 Cleaning Nozzle Brush from the 8S-2245 Cleaning Tool Group in order to remove any loose carbon from the
nozzle tip.

Refer to Special Instruction, SEHS8627 "Use Of 8S-2245 Nozzle Cleaning Tool Group" for tool usage and cleaning procedure.

DO NOT use a steel brush or a wire wheel to clean the nozzle tip. These tools can cause a
reduction of orifice size as shown at location (Y). This type nozzle damage can cause a
large change in engine horsepower. The illustration shows a normal orifice at location (X)
and an orifice at location (Y) that has been damaged by an incorrect cleaning procedure.

Pencil-Type Fuel Nozzle Part Number Reference Chart

 DO NOT use a steel brush or a wire wheel to clean the nozzle body or the nozzle tip. Use of
these tools can cause a reduction of orifice size as shown at location (Y) and cause a large
reduction of engine horsepower. The illustration shows a normal orifice at location (X)
and an orifice at location (Y) that has been damaged by wire brushing. Excessive brushing
will also remove the coating. Stain on the nozzle coating is normal.

Use needle nose pliers to remove and discard compression seal (1) and carbon dam (2). Use care to avoid damaging the nozzle.

Caterpillar And Supplier Pencil-Type Fuel Nozzle Part Number Cross-Reference Chart

The only identification given on some pencil-type nozzles is the supplier part number. Use the following chart to cross-reference
specific nozzles between the supplier part number and the Caterpillar part number.
Test Sequence for Pencil-Type Fuel Nozzles

NOTE: The cap on these nozzles must be removed to prevent hydraulic lock or incorrect VOP measurement during testing.

1. Position 8S-2250 Nozzle Holding Tool (1) in a vise.

2. Position the nozzle in the holding tool. Remove cap (2).

Return Leakage Test (Except Type A Nozzles)

Position of nozzle for return leakage test

1. Position the top of the nozzle slightly below the horizontal.

Wrap a clean shop towel around the nozzle tip, as shown, in order to absorb any test fluid that may flow out of a defective nozzle.

2. OPEN gauge protector valve (4) and pump isolator valve (5) one-half turn.

CLOSE On/Off valve (6).

3. Apply and hold a pressure of 9650 kPa (1400 psi) to 11 030 kPa (1600 psi).

4. Count the leakage for fifteen seconds after the first drop falls.
5. If leakage is NOT within Return Leakage Specifications, STOP the test. DO NOT use the nozzle.

Nozzle Installation For Pencil-Type (A, B And C) Fuel Injection Nozzles

Install 6V-2171 Tube Assembly (1) and 5P-4244 Direct Injection Nozzle Adapter (2) on the tester, for all 3208-type pencil-type fuel
nozzles except 7N-0449 Fuel Injection Nozzle Assembly. The 3300-type 7N-0449 Fuel Injection Nozzle Assembly requires 5P-7448
Flat Seat Fuel Valve Adapter.

Illustration of 1H-1023 O-ring Seal (1) on typical nozzle assembly.

Inspect 1H-1023 O-ring Seal (1) for damage on all nozzles except 7N-0499.

Install nozzle (3) on adapter (2) so the tip is approximately 15 degrees from vertical [dimension (A)] toward the rear of the tester as
shown and inside 8S-2270 Fuel Collector Assembly and FT-1384 or 1U-8857 Extension Tube.

Turn On/Off valve (4) to the CLOSED position. OPEN pump isolator valve (5) and 0-25 000 kPa (0-3625 psi) gauge protector valve
(6) one-half turn.

Valve Opening Pressure (VOP) Test

1. Change the position of the nozzle so the nozzle tip is inside FT-1384 or 1U-8857 Extension Tube and 8S-2270 Fuel Collector
Assembly.

2. As shown, place a clean shop towel around the top of the nozzle in order to absorb any return leakage.

3. OPEN gauge protector valve (4) one-half turn.

4. SLOWLY increase the pressure until test fluid flows from the nozzle orifices.

5. If the VOP is NOT within VOP Specifications, STOP the test.

DO NOT use the nozzle.

Nozzle Flushing Procedure

NOTE: The nozzle must be flushed clean before the Tip Leakage Test:

1. CLOSE gauge protector valve (4).

2. Pump the tester three rapid FULL strokes.

3. OPEN gauge protector valve (4).

Tip Leakage Test

1. Wipe dry the nozzle tip and body.

Wrap a clean, lint-free cloth around the top of the nozzle (pressure screw end) in order to prevent bleed-back fluid from draining down
and dripping off the nozzle tip.

2. Apply a pressure of 1380 kPa (200 psi) below the minimum VOP.

Hold this pressure fifteen seconds.

3. If the tip leakage is NOT within the Tip Leakage Specifications, STOP the test.
DO NOT use the nozzle.

Refer to the "Troubleshooting Guide" in this manual.

Spray Pattern Test

NOTE: Use 8S-2257 Loupe from 8S-2245 Cleaning Tool Group or 6V-2196 Inspection Microscope in order to visually inspect the
nozzle orifices and in order to inspect for any indication of orifice plugging or damage.

1. RAPIDLY increase the pressure (full stroke in less than one second) until the nozzle valve opens and test fluid flows from the tip.
The test fluid spray is similar to Illustration A shown as SATISFACTORY. The fluid must spray from all orifices.

NOTE: "RAPIDLY increase the pressure" is defined as:

· Each full pump stroke is performed in LESS than one second.

· The nozzle must produce a pattern as shown in the Illustration A.

· The test fluid must flow evenly from all orifices.

Illustration A. SATISFACTORY fluid spray.

2. DO NOT use a nozzle that has an unsatisfactory fluid flow, such as that in Illustration B shown as UNSATISFACTORY:
PLUGGED ORIFICE and Illustration C shown as UNSATISFACTORY: HORIZONTAL DEFECTION.

Illustration B. UNSATISFACTORY fluid spray: PLUGGED ORIFICE

Illustration C. UNSATISFACTORY fluid spray: HORIZONTAL DEFLECTION.

NOTE: If it is difficult to view all orifices at one time, it is permissible to use a slow stroke to verify that all orifices are open.

A RAPID stroke must be used, however, for the final test.

NOTE: This completes the test sequence for Type B 9L-9263, 9L-7883, and 9N-2366 Nozzle Assemblies.

Installation Of Cap (Type A And C Nozzles Only)

1. Remove the nozzle from the tester and install it in 8S-2250 Nozzle Holding Tool. Position the tool, with nozzle, in a vise.

2. Install new 1H-1023 O-ring Seal (1) and cap (2). Tighten cap (2) to a torque of 12.0 N·m (106 lb in) to 14.0 N·m (124 lb in).

NOTE: Do not over-tighten cap (2).

Cap Leakage Test

1. Install the nozzle on 5P-4150 Tester Group.

Position the nozzle so its spray is directed into 8S-2270 Fuel Collector Assembly and FT-1384 or 1U-8857 Extension Tube.
2. Pump the tester until cap (1) is completely full of fuel and the pressure on the gauge is 20 700 kPa (3000 psi).

NOTE: It may take 15-20 strokes to reach 20 700 kPa (3000 psi).

NOTE: A hydraulic lock can prevent the nozzle from opening when the cap is completely full of test fluid.

This can happen when the nozzle is on the nozzle tester because of the large volume of test fluid delivered by the nozzle tester pump
and the pressure held in the line at the end of each pump stroke.

A fuel system that operates correctly on-engine will not permit a hydraulic lock to occur in the nozzle.

OPEN the nozzle tester On/Off valve to release trapped pressure. Remove the nozzle from the tester.

3. Install new compression seal (3). Use 6V-4979 Carbon Stop Seal Tool to install new carbon dam (2).

Inspect For Damage

Inspect for damage caused by:

· Steel wire brushing.

· Partially melted carbon dam seal.
NOTE: Engine overheating can cause carbon dam seal material to melt and thinly adhere up the side of the nozzle body.
If this condition is found, replace the entire set of fuel nozzles.

NOTE: Use 8S-2257 Loupe, from 8S-2245 Nozzle Cleaning Tool Group or 6V-2196 Inspection Microscope, to visually inspect
nozzle orifices and to visually inspect for indication of orifice plugging or damage.

Inspect for any other obvious damage.

DO NOT use damaged fuel nozzles.

Nozzle Installation For Caterpillar 7000 Series Direct Injection Nozzles

Remove bleed screw (1) and seal from nozzle (2).

NOTE: On Caterpillar 7000 Series Nozzles with a date code of H7 and newer, it will be necessary to also use 1U-5895 Insert Bit to
remove the Type B bleed screw that is shown in the illustration.

NOTE: 104-9450 thru 104-9455 Nozzle Assemblies DO NOT have bleed screws.

Installation Of 3300 Engine Nozzles.

Install 6V-2170 Tube Assembly (3) and 5P-7448 Fuel Valve Adapter (4) on nozzle tester (5).

Install nozzle (2) on adapter (4) so the hole for bleed screw (1) is toward nozzle tester (5).

Installation Of 3400 Engine Nozzles.

Install 5P-4721 Tube (10), 5P-4244 Nozzle Adapter (11), and FT-1743 Line Assembly (12) [fabricate from 1W-4660 Fuel Injector
Line Assembly] on nozzle tester (5).
Install nozzle (9) on FT-1741 Line Assembly (12).

Installation Of 3200 Engine Nozzles.

Install 5P-4721 Tube (10) and 5P-4244 Nozzle Adapter (11) on nozzle tester (5).

Install nozzle (2) on adapter (11).

Turn On/Off valve (6) to the CLOSED position.

OPEN pump isolator valve (7) and 0-40,000 kPa (0-5800 psi) gauge protector valve (8) one-half turn.

Wrap a clean shop towel around the nozzle body.

Install 8S-2270 Fuel Collector Assembly and FT-1384 or 1U-8857 Extension Tube in the position as shown.

VALVE OPENING PRESSURE (VOP) TEST

1. SLOWLY increase the pressure until the test fluid just begins to flow from the nozzle tip.

NOTE: An audible click may be heard and a small spurt of fuel may be seen before the VOP is reached. This is a proper function of
104-9450 through 104-9455 Nozzle Assemblies.

2. If VOP is NOT within VOP Specifications, STOP the test.

DO NOT use the nozzle.

Nozzle Flushing Procedure

1. CLOSE gauge protector valve (8).

2. Pump the tester three full strokes.

3. OPEN gauge protector valve (8).

Tip Leakage Test

1. Wipe dry the nozzle tip and body. Wrap a clean, lint-free cloth around the top of the nozzle (covering the bleed screw hole) in order
to prevent bleed-back fluid from draining down and dripping off the nozzle tip.

2. Apply a pressure of 1380 kPa (200 psi) below the valve opening pressure (VOP) )(as measured in Step 2).

Maintain this pressure for fifteen seconds.

3. If the tip leakage is NOT within the Tip Leakage Specification, STOP the test.

DO NOT use the nozzle.

Spray Pattern Test

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Testing & Adjusting
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Air Inlet And Exhaust System

Restriction Of Air Inlet And Exhaust

There will be a reduction of horsepower and efficiency of the engine if there is a restriction in the air inlet or exhaust system.

Air flow through the air cleaner must not have a restriction (negative pressure difference measurement between atmospheric air and air that
has gone through air cleaner) of more than 7.47 kPa (30 inches of H2O).

Back pressure from the exhaust (pressure difference measurement between exhaust at outlet elbow and atmospheric air) must not be more
than 6.72 kPa (27 inches of H2O).

Measurement Of Pressure In Inlet Manifold

The efficiency of an engine can be checked by making a comparison of the pressure in the inlet manifold with the information given in the
TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche. This test is used when there is a decrease of
horsepower from the engine, yet there is no real sign of a problem with the engine.

The correct pressure for the inlet manifold is given in the TMI (Technical Marketing Information) or Fuel Setting And Related Information
Fiche. Development of this information is done with these conditions:

a. 99 kPa (29.7 inches of Hg) barometric pressure.

b. 29°C (85°F) outside air temperature.

c. 35 API rated fuel

Any change from these conditions can change the pressure in the inlet manifold. Outside air that has higher temperature and lower
barometric pressure than given above will cause a lower horsepower and a lower inlet manifold pressure measurement than given in the
TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche. Outside air that has a lower temperature and a
higher barometric pressure will cause higher horsepower and a higher inlet manifold pressure measurement.

A difference in fuel rating will also change horsepower and the pressure in the inlet manifold. If the fuel is rated above 35 API, pressure in
the inlet manifold can be less than given in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche. If
the fuel is rated below 35 API, the pressure in the inlet manifold can be more than given in the TMI (Technical Marketing Information) or
Fuel Setting And Related Information Fiche. Be Sure That The Air Inlet And Exhaust Do Not Have A Restriction When Making A Check
Of Pressure In The Inlet Manifold.

Plug For Pressure Test

(A) Plug. (B) Exhaust elbow. (C) Pipe to inlet manifold.

Use the 1U5470 Engine Pressure Group to check the pressure in the inlet manifold.

Remove plug (A) on inlet pipe to measure inlet manifold pressure.

1U5470 Engine Pressure Group

This tool group has a indicator to read pressure in the inlet manifold. Special Instruction SEHS8907 is with the tool group and gives
instructions for its use.

Turbocharger

If any unusual sound or vibration in the turbocharger is noticed, a quick check of bearing condition can be made without disassembling the
turbocharger. This can be done by removing the piping from the turbocharger and inspecting the compressor impeller, turbine wheel and
compressor cover. Rotate the compressor and turbine wheel assembly by hand and observe by feeling excess end play. The rotating
assembly should rotate freely with no rubbing or binding. If there is any indication of the impeller rubbing the compressor cover or the
turbine wheel rubbing the turbine housing, recondition the turbocharger or replace with a new or rebuilt one.

End clearance is best checked with a dial indicator. Attach a dial indicator with the indicator point on the end of the shaft. Move the shaft
from end to end making note of the total indicator reading.

If end play is more than the maximum end play allowable, rebuild or replace the turbocharger. End play less than the minimum end play
allowable could indicate carbon build up on the turbine wheel and the turbocharger should be disassembled for cleaning and inspection.

Checking Turbocharger Rotating Assembly End Play (Typical Example)

A more reliable check of bearing conditions can be made only when the turbocharger is disassembled and the bearings, shaft journal and
housing bore diameters can actually be measured.

Exhaust Temperature
Use the 123-6700 Infrared Thermometer II to check exhaust temperature. Operator's Manual, NEHS0630 is with the tool group and gives
instructions for the test procedure.

Crankcase (Crankshaft Compartment) Pressure

Pistons or rings that have damage can be the cause of too much pressure in the crankcase. This condition may cause the engine to run
rough. There will also be more than the normal amount of fumes (blowby) coming from the crankcase breather. The breather can then
become restricted in a very short time, causing oil leakage at gaskets and seals that would not normally have leakage. Other sources of
blowby can be worn valve guides or turbocharger seal leakage.

8T2700 Indicator Group

The 8T2700 Indicator Group is used to check the amount of blowby. The test procedure is in Special Instruction, SEHS8712.

Compression

An engine that runs rough can have a leak at the valves, or have valves that need adjustment. Use the test that follows for a fast and easy
method to find a cylinder that has low compression, or does not have good fuel combustion. Find the speed that the engine runs the
roughest, and keep the engine at this rpm until the test is finished. Loosen the fuel line nut at a fuel injection pump to stop the flow of fuel
to that cylinder. Do this for each cylinder until a loosened fuel line is found that makes no difference in engine performance. Be sure to
tighten each fuel line nut after the test before the next fuel line nut is loosened. This test can also be an indication that the fuel injection is
wrong, so the cylinder will have to be checked thoroughly. Removal of the head and inspection of the valves and valve seats is necessary to
find those small defects that do not normally cause a problem. Repair of these problems is normally done when reconditioning the engine.
Cylinder Head

The cylinder head has valve seat inserts, valve guides and bridge dowels that can be removed when they are worn or have damage.
Replacement of these components can be made with the tools that follow.

Valves

Valve removal and installation is easier with use of the 5S1330 Valve Spring Compressor Assembly and 5S1322 Valve Keeper Inserter.

Valve Seat Inserts

Tools needed to remove and install valve seat inserts are in the 6V4805 Valve Insert Puller Group. Special Instruction, SMHS7935 gives an
explanation for the procedure to remove the valve seat inserts. For easier installation, lower the temperature of the insert before it is
installed in the head.

Valve Guides

Tools needed to remove and install valve guides are the 5P2396 Driver Bushing and 9U7349 Driver. The counterbore in the driver bushing
installs the guide to the correct height. Use a 1P7451 Valve Guide Honing Group to make a finished bore in the valve guide after
installation of the guide in the head. Special Instruction, SMHS7526 gives an explanation for this procedure. Grind the valves after the new
valve guides are installed.

Checking Valve Guide Bores

Use the 5P3536 Valve Guide Gauge Group to check the bore of the valve guides. Special Instruction, GMG02562 gives complete and
detailed instructions for use of the 5P3536 Valve Guide Gauge Group.

Bridge Dowel

Use a 5P0944 Dowel Puller Group with a 5P0942 Extractor to remove the bridge dowels. Install a new bridge dowel with a 5P2406 Dowel
Driver. This dowel driver installs the bridge dowel to the correct height.

Bridge Adjustment

When the head is disassembled, keep the bridges with their respective cylinders. Adjustment of the bridge will be necessary after the valves
are ground or other reconditioning of the cylinder head is done. The bridge should be checked and/or adjusted each time the valves are
adjusted. Use the procedure that follows to make an adjustment to the bridge.

Bridge Adjustment

NOTE: Valves must be fully closed.

1. Put engine oil on the bridge dowel in the cylinder head and in the bore in the bridge.
2. Install the bridge with the adjustment screw toward the exhaust manifold.

3. Loosen the locknut for the adjustment screw and loosen the adjustment screw several turns.

4. Put a force on the bridge with a finger to keep the bridge in contact with the valve stem opposite the adjustment screw.

5. Turn the adjustment screw clockwise until it just makes contact with the valve stem. Then turn the adjustment screw 30 degrees more in
a clockwise direction to make the bridge straight on the dowel, and to make compensation for the clearance in the threads of the adjustment
screw.

6. Hold the adjustment screw in this position and tighten the locknut to 30 ± 4 N·m (22 ± 3 lb ft).

7. Put engine oil at the point where the rocker arm makes contact with the bridge.

Valve Lash Setting

NOTE: Valve lash is measured between the rocker arm and the bridge for the valves.

Valve Lash

To make an adjustment to the valve lash, use the procedure that follows:

Valve Lash Adjustment

1. Put No. 1 piston at top center (TC) on the compression stroke. Make reference to Finding Top Center Compression Position For No. 1
Piston.
2. Make an adjustment to the valve lash on the inlet valves for cylinders:

3408C . . . 1,2,5,7

3412C . . . 1,3,6,7,12

Make an adjustment to the valve lash on the exhaust valves for cylinders:

3408C . . . 1,3,4,8

3412C . . . 1,4,5,8,9,12

3. Loosen the locknut for the push rod adjustment screw and turn the screw counterclockwise to increase the valve lash.

4. Put a feeler gauge of the correct dimension between the rocker arm and bridge contact surface. Turn the adjustment screw clockwise
until the valve lash is set to specifications in the chart Valve Lash Setting: Engine Stopped.

5. After each adjustment, tighten the nut for the adjustment screw to a torque of 30 ± 4 N·m (22 ± 3 lb ft) and check the adjustment again.

3408C Cylinder And Valve Location

3412C Cylinder And Valve Location

6. Remove the timing bolt and turn the flywheel 360 degrees in the direction of normal engine rotation. This will put No. 8 piston at top
center (TC) on the compression stroke for the 3408C and No. 11 piston at top center (TC) on the compression stroke for the 3412C. Install
the timing bolt in the flywheel.

7. Make an adjustment to the valve lash on the inlet valves for cylinders:

3408C . . . 3,4,6,8

3412C . . . 2,5,8,9,10,11

Make an adjustment to the valve lash on the exhaust valves for cylinders:

3408C . . . 2,5,6,7

3412C . . . 2,3,6,7,10,11

8. Loosen the locknut for the push rod adjustment screw and turn the screw counterclockwise to increase the valve lash.

9. Put a feeler gauge of the correct dimension between the rocker arm and bridge contact surface. Turn the adjustment screw clockwise
until the valve lash is set to specifications in the chart Valve Lash Setting: Engine Stopped.

10. After each adjustment, tighten the nut for the adjustment screw to a torque of 30 ± 4 N·m (22 ± 3 lb ft) and check the adjustment again.

11. Remove the timing pin from the flywheel after all valve lash adjustments are correct.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Testing & Adjusting
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Cylinder Head

The cylinder head has valve seat inserts, valve guides and bridge dowels that can be removed when they are worn or have damage.
Replacement of these components can be made with the tools that follow.

Valves

Valve removal and installation is easier with use of the 5S1330 Valve Spring Compressor Assembly and 5S1322 Valve Keeper Inserter.

Valve Seat Inserts

Tools needed to remove and install valve seat inserts are in the 6V4805 Valve Insert Puller Group. Special Instruction, SMHS7935 gives an
explanation for the procedure to remove the valve seat inserts. For easier installation, lower the temperature of the insert before it is
installed in the head.

Valve Guides

Tools needed to remove and install valve guides are the 5P2396 Driver Bushing and 9U7349 Driver. The counterbore in the driver bushing
installs the guide to the correct height. Use a 1P7451 Valve Guide Honing Group to make a finished bore in the valve guide after
installation of the guide in the head. Special Instruction, SMHS7526 gives an explanation for this procedure. Grind the valves after the new
valve guides are installed.

Checking Valve Guide Bores

Use the 5P3536 Valve Guide Gauge Group to check the bore of the valve guides. Special Instruction, GMG02562 gives complete and
detailed instructions for use of the 5P3536 Valve Guide Gauge Group.

Bridge Dowel

Use a 5P0944 Dowel Puller Group with a 5P0942 Extractor to remove the bridge dowels. Install a new bridge dowel with a 5P2406 Dowel
Driver. This dowel driver installs the bridge dowel to the correct height.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Testing & Adjusting
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Bridge Adjustment

When the head is disassembled, keep the bridges with their respective cylinders. Adjustment of the bridge will be necessary after the valves
are ground or other reconditioning of the cylinder head is done. The bridge should be checked and/or adjusted each time the valves are
adjusted. Use the procedure that follows to make an adjustment to the bridge.

Bridge Adjustment

NOTE: Valves must be fully closed.

1. Put engine oil on the bridge dowel in the cylinder head and in the bore in the bridge.

2. Install the bridge with the adjustment screw toward the exhaust manifold.

3. Loosen the locknut for the adjustment screw and loosen the adjustment screw several turns.

4. Put a force on the bridge with a finger to keep the bridge in contact with the valve stem opposite the adjustment screw.

5. Turn the adjustment screw clockwise until it just makes contact with the valve stem. Then turn the adjustment screw 30 degrees more in
a clockwise direction to make the bridge straight on the dowel, and to make compensation for the clearance in the threads of the adjustment
screw.

6. Hold the adjustment screw in this position and tighten the locknut to 30 ± 4 N·m (22 ± 3 lb ft).

7. Put engine oil at the point where the rocker arm makes contact with the bridge.

Valve Lash Setting

NOTE: Valve lash is measured between the rocker arm and the bridge for the valves.
Valve Lash

To make an adjustment to the valve lash, use the procedure that follows:

Valve Lash Adjustment

1. Put No. 1 piston at top center (TC) on the compression stroke. Make reference to Finding Top Center Compression Position For No. 1
Piston.

2. Make an adjustment to the valve lash on the inlet valves for cylinders:

3408C . . . 1,2,5,7

3412C . . . 1,3,6,7,12

Make an adjustment to the valve lash on the exhaust valves for cylinders:

3408C . . . 1,3,4,8

3412C . . . 1,4,5,8,9,12

3. Loosen the locknut for the push rod adjustment screw and turn the screw counterclockwise to increase the valve lash.

4. Put a feeler gauge of the correct dimension between the rocker arm and bridge contact surface. Turn the adjustment screw clockwise
until the valve lash is set to specifications in the chart Valve Lash Setting: Engine Stopped.

5. After each adjustment, tighten the nut for the adjustment screw to a torque of 30 ± 4 N·m (22 ± 3 lb ft) and check the adjustment again.
3408C Cylinder And Valve Location

3412C Cylinder And Valve Location

6. Remove the timing bolt and turn the flywheel 360 degrees in the direction of normal engine rotation. This will put No. 8 piston at top
center (TC) on the compression stroke for the 3408C and No. 11 piston at top center (TC) on the compression stroke for the 3412C. Install
the timing bolt in the flywheel.

7. Make an adjustment to the valve lash on the inlet valves for cylinders:

3408C . . . 3,4,6,8

3412C . . . 2,5,8,9,10,11
Make an adjustment to the valve lash on the exhaust valves for cylinders:

3408C . . . 2,5,6,7

3412C . . . 2,3,6,7,10,11

8. Loosen the locknut for the push rod adjustment screw and turn the screw counterclockwise to increase the valve lash.

9. Put a feeler gauge of the correct dimension between the rocker arm and bridge contact surface. Turn the adjustment screw clockwise
until the valve lash is set to specifications in the chart Valve Lash Setting: Engine Stopped.

10. After each adjustment, tighten the nut for the adjustment screw to a torque of 30 ± 4 N·m (22 ± 3 lb ft) and check the adjustment again.

11. Remove the timing pin from the flywheel after all valve lash adjustments are correct.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Testing & Adjusting
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Lubrication System

One of the problems in the list that follows will generally be an indication of a problem in the lubrication system for the engine.

Too Much Oil Consumption

Oil Pressure Is Low

Oil Pressure Is High

Too Much Bearing Wear

Increased Oil Temperature

Too Much Oil Consumption

Oil Leakage On Outside Of Engine

Check for leakage of the seals at each end of the crankshaft. Look for leakage at the oil pan gasket and all lubrication system connections.
Check to see if oil comes out of the crankcase breather. This can be caused by combustion gas leakage around the pistons. A dirty
crankcase breather will cause high pressure in the crankcase, and this will cause gasket and seal leakage.

Oil Leakage Into Combustion Area Of Cylinders

Oil leakage into the combustion area of the cylinders can be the cause of blue smoke. There are four possible ways for oil leakage into the
combustion area of the cylinders:

1. Oil leakage between worn valve guides and valve stems.

2. Worn or damaged piston rings, or dirty oil return holes.

3. Compression ring and/or intermediate ring not installed correctly.

4. Oil leakage past the seal rings in the impeller end of the turbocharger shaft.

Too much oil consumption can also be the result if oil with the wrong viscosity is used. Oil with a thin viscosity can be caused by fuel
leakage into the crankcase, or by increased engine temperature.

Measuring Engine Oil Pressure

An oil pressure indicator that has a defect can give an indication of low oil pressure.

The 1U5470 Engine Pressure Group can be used to check engine oil pressure.
1U5470 Engine Pressure Group

This tool group has a indicator to read oil pressure in the engine. Special Instruction, SEHS8524, is with the tool group and gives
instructions for the test procedure.

1. Be sure that the engine is filled to the correct level with SAE 10W30 oil. If any other viscosity of oil is used, the information in the
Engine Oil Pressure Graph does not apply.

2. Connect the 1U5470 Engine Pressure Group to the main oil manifold at location (1).

3. Operate the engine to get it up to normal operating temperature.

Oil Manifold (Typical Example)

(1) Pressure test location.

4. Keep the oil temperature constant with the engine at its rated rpm, and read the pressure indicator.

NOTE: Make sure engine oil temperature does not go above 115°C (239°F).

5. On the Engine Oil Pressure Graph, find the point that the lines for engine rpm and oil pressure intersect (connect).
Engine Oil Pressure Graph

6. If the results do not fall within the "Acceptable" pressure range given in the graph, find the cause and correct it. Engine failure or a
reduction in engine life can be the result if engine operation is continued with oil manifold pressure outside this range.

NOTE: A record of engine oil pressure, kept at regular intervals, can be used as an indication of possible engine problems or damage. If
there is a sudden increase or decrease of 70 kPa (10 psi) in oil pressure, even though the pressure is in the "Acceptable" range on the graph,
the engine should be inspected and the problem corrected.

Oil Pressure Is Low

Crankcase Oil Level

Check the level of the oil in the crankcase. Add oil if needed. It is possible for the oil level to be too far below the engine oil pump supply
tube. This will cause the engine oil pump to not have the ability to supply enough lubrication to the engine components.

Engine Oil Pump Does Not Work Correctly

The inlet screen of the supply tube for the engine oil pump can have a restriction. This will cause cavitation (low pressure bubbles suddenly
made in liquids by mechanical forces) and a loss of oil pressure. Air leakage in the supply side of the engine oil pump will also cause
cavitation and loss of oil pressure. If the bypass valve for the engine oil pump is held in the open (unseated) position, the lubrication system
can not get to maximum pressure. Engine oil pump gears that have too much wear will cause a reduction in oil pressure.

Oil Filter Bypass Valves

If the bypass valve for the engine oil filter is held in the open position (unseated) because the engine oil filter has a restriction, a reduction
in oil pressure can result. To correct this problem, remove and clean the bypass valve and bypass valve bore. Install a new engine oil filter
to be sure that no more debris makes the bypass valve stay open.

Too Much Clearance At Engine Bearings Or Open Lubrication System (Broken Or Disconnected Oil Line Or Passage)

Components that are worn and have too much bearing clearance can cause oil pressure to be low. Low oil pressure can also be caused by an
oil line or oil passage that is open, broken or disconnected.

Piston Cooling Tubes (Jets)

When engine is operated, cooling jets direct oil toward the bottom of the piston to lower piston and ring temperatures. If there is a failure of
one of the jets, or it is bent in the wrong direction, seizure of the piston will be caused in a very short time.
Use the 5P8709 Piston Tool Group to check and adjust the alignment of piston cooling jets.

Oil Pressure Is High

Oil pressure will be high if the bypass valve for the engine oil pump can not move from the closed position.

Too Much Bearing Wear

When some components of the engine show bearing wear in a short time, the cause can be a restriction in an oil passage. A broken oil
passage can also be the cause.

If the indicator for oil pressure shows enough oil pressure, but a component is worn because it can not get enough lubrication, look at the
passage for oil supply to the component. A restriction in a supply passage will not let enough lubrication get to a component, and this will
cause early wear.

Increased Oil Temperature

Look for a restriction in the oil and coolant passages of the engine oil cooler. If the engine oil cooler has a restriction, the oil temperature
will be higher than normal when the engine is operated. The oil pressure of the engine will not get low just because the engine oil cooler
has a restriction.

Also check the engine oil cooler bypass valve to see if it is held in the open position (unseated). This condition will let the oil through the
valve instead of the engine oil cooler, and oil temperature will increase.

Cooling System

This engine has a pressure type cooling system. A pressure type cooling system gives two advantages. The first advantage is that the
cooling system can have safe operation at a temperature that is higher than the normal boiling (steam) point of water. The second advantage
is that this type system prevents cavitation (low pressure bubbles suddenly made in liquids by mechanical forces) in the water pump. With
this type system, it is more difficult for an air or steam pocket to be made in the cooling system.

The cause for increased engine temperature is generally because regular inspections of the cooling system were not made. Make a visual
inspection of the cooling system before a test is made with test equipment.

Visual Inspection Of The Cooling System

1. Check coolant level in the cooling system.

2. Look for leaks in the system.

NOTE: Water pump seals. A small amount of coolant leakage across the surface of the "face-type" seals is normal, and required, to
provide lubrication for this type of seal. A hole is provided in the water pump housing to allow this coolant/seal lubricant to drain from the
pump housing. Intermittent leakage of small amounts of coolant from this hole is not an indication of water pump seal failure. Replace the
water pump seals only if a large amount of leakage, or a constant flow of coolant is observed draining from the water pump housing.

3. Look for bent radiator fins. Be sure that air flow through the radiator does not have a restriction.

4. Inspect the drive belts for the fan.

5. Check for damage to the fan blades.

6. Look for air or combustion gas in the cooling system.

7. Inspect the filler cap and the surface that seals the cap. This surface must be clean.

Testing The Cooling System

Remember that temperature and pressure work together. When a diagnosis is made of a cooling system problem, temperature and pressure
must both be checked. Cooling system pressure will have an effect on cooling system temperatures. For an example, look at the chart to see
the effect of pressure and height above sea level on the boiling (steam) point of water.

Test Tools For Cooling System

4C6500 Digital Thermometer Group

The 4C6500 Digital Thermometer Group is used in the diagnosis of overheating (engine hotter than normal) or overcooling (engine cooler
than normal) problems. This group can be used to check temperatures in several different parts of the cooling system. The testing procedure
is in Operating Manual, NEHS0554.

8T2700 Blowby/Air Flow Indicator Group

The 8T2700 Blowby/Air Flow Indicator Group is used to check the air flow through the radiator core. The test procedure is in Special
Instruction, SEHS8712.

9U7400 Multitach Group

The 9U7400 Multitach Group is used to check the fan speed. Refer to Operator's Manual, NEHS0605, for the operating instructions for this
tool.

9S8140 Cooling System Pressurizing Pump Group

The 9S8140 Cooling System Pressurizing Pump Group is used to test pressure caps and to pressure check the cooling system for leaks.

DO NOT loosen the filler or pressure cap on a hot engine. Steam or hot coolant can
cause severe burns.

Filler Cap And Pressure Relief Valve

Typical Pressure Relief Valve System

(1) Pressure relief valve. (2) Stud for filler cap.

The 9S8140 Cooling System Pressurizing Pump Group is used to test pressure relief valves and to pressure check the cooling system for
leaks.

9S8140 Cooling System Pressurizing Pump Group

(3) Release valve. (4) Adapter. (5) Hose.

One cause for a pressure loss in the cooling system can be a bad seal on the radiator filler cap.

DO NOT loosen the filler cap or pressure cap on a hot engine. Steam or hot coolant
can cause severe burns.

1. After the engine is cool, loosen the filler cap and let the pressure out of the cooling system. Then remove the filler cap.

2. Inspect the filler cap carefully. Look for damage to the seal or to the surface that seals. Any foreign material or deposits on the cap, seal
or surface that seals, must be removed.

Use the procedure that follows to pressure check the cooling system.

1. Make sure the coolant level is above the top of the radiator core.

2. Install and tighten the filler cap.

3. Remove hose (5) from adapter (4).

4. Remove the pressure test plug for the radiator top tank.

5. Install the end of hose (5) in the hole for the pressure test plug as shown.

6. Operate the pump until the pointer on the pressure indicator no longer increases. The highest pressure indication on the indicator is the
point that the relief valve opens. The correct pressure that makes the relief valve open is 105 to 125 kPa (15 to 18 psi).

7. If the relief valve does not open within pressure specification, replacement of the relief valve is necessary.

8. If the relief valve is within specifications, check the radiator for outside leakage.

9S8140 Pump Group Installed

9. Check all connections and hoses of the cooling system for outside leakage.

10. If you do not see any outside leakage and the pressure reading on the indicator is still the same after five minutes, the radiator and
cooling system does not have leakage. If the reading on the indicators goes down and you do not see any outside leakage, there is leakage
on the inside of the cooling system. Make repairs as necessary.
 If a pressure indication is shown on the indicator, to avoid personal injury push
release valve (3) to release all pressure in the system before removal of hose (5) from
the radiator.

11. Remove hose (5) from radiator test pressure location.

12. Install plug in pressure test location.

Indicator For Water Temperature

Water Temperature Connection

(1) Sending unit.

If the engine gets too hot and a loss of coolant is a problem, a pressure loss in the cooling system could be the cause. If the indicator for
water temperature shows that the engine is getting too hot, look for coolant leakage. If a place cannot be found where there is coolant
leakage, check the accuracy of the indicator for water temperature. A temperature indicator of known accuracy can be connected at the
location for sending unit (1) to make this check. Also, the 4C6500 Digital Thermometer Group or the 2F7112 Thermometer and 6B5072
Bushing can be used.

Work carefully around an engine that is running. Engine parts that are hot, or parts
that are moving, can cause personal injury.
Start the engine and run it until the temperature is at the desired range according to the test indicator or thermometer. If necessary, put a
cover over part of the radiator or cause a restriction of the coolant flow. The reading on the indicator for water temperature must be the
same as the test indicator or thermometer within the tolerance range in the chart in Specifications, 3408C & 3412C Industrial Engines,
SENR1136.

Water Temperature Regulators

1. Remove the regulator from the engine.

2. Heat water in a pan until the temperature is 92°C (197°F). Move the water around in the pan to make it all the same temperature.

3. Hang the regulator in the pan of water. The regulator must be below the surface of the water and it must be away from the sides and
bottom of the pan.

4. Keep the water at the correct temperature for ten minutes.

5. After ten minutes, remove the regulator and immediately measure the distance the regulator has opened. The distance must be a
minimum of 10.4 mm (.41 in).

6. If the distance is less than 10.4 mm (.41 in), make a replacement of the regulator.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Testing & Adjusting
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Basic Block

Piston Rings

This engine has piston grooves and rings of the Keystone (taper) design. The 1U6431 Gage Group is available to check the top two ring
grooves in the piston. For correct use of the gage group see the instruction card that is with the gage group.

Connecting Rods And Pistons

Use the 7M3978 Piston Ring Expander to remove or install piston rings.

Use the 5P3526 Piston Ring Compressor to install pistons into cylinder block.

Tighten the connecting rod bolts in the step sequence that follows:

1. Put engine oil on bolt threads and contact surfaces of nut and cap.

2. Tighten all bolts to 80 ± 8 N·m (60 ± 6 lb ft).

3. Put a mark on each nut and end of bolt.

4. Tighten each nut 120 ± 5 degrees from the mark.

The connecting rod bearings fit tightly in the bore in the rod. If bearing joints or backs are worn (fretted), check bore size. This can be an
indication of wear because of a loose fit.

Connecting Rod And Main Bearings

Connecting rod bearings are available with 0.64 mm (.025 in) and 1.27 mm (.050 in) smaller inside diameter than the original size bearings.
These bearings are for crankshafts that have been "ground" (made smaller than the original size).

Main bearings are available with a larger outside diameter than the original size bearings. These bearings are for cylinder blocks that have
had the bore for the main bearings "bored" (made larger than the original size). The size available is 0.64 mm (.025 in) larger outside
diameter than the original size bearings.

Cylinder Block
1P3537 Dial Bore Gauge Group

The bore in the block for main bearings can be checked with the main bearing caps installed without bearings. Tighten the nuts that hold
the caps to the torque shown in the Specifications module. Alignment error in the bores must not be more than 0.08 mm (.003 in). Special
Instruction, SMHS7606 gives instructions for the use of 1P4000 Line Boring Tool Group for alignment of the main bearing bores. The
1P3537 Dial Bore Gauge Group can be used to check the size of the bores. Special Instruction, GMG00981 is with the group.

Cylinder Liner Projection

(1) Bolt. (2) Steel washer. (3) Fabric washer.

Install larger diameter washers (4) and (5) under bolts marked "X".

Install smaller diameter washers (6) and (7) under remaining two bolts.

1. Install clean liners or cylinder packs (without the filler band or the rubber seals), spacer plate gasket and clean spacer plate.
2. Install bolts and washers, as indicated previously, in the holes. Install all bolts or the six bolts around the liner. Tighten the bolts to a
torque of 95 N·m (70 lb ft).
3. Use the 8T0455 Liner Projection Tool Group to measure liner projection at positions indicated with an A,B,C and D. Record
measurements for each cylinder. Add the four readings for each cylinder and divide by four to find the average.

4. The cylinder liner specifications are as follows:

Liner projection . . . 0.025 to 0.152 mm (.0010 to .0060 in)

Maximum variation in each cylinder . . . 0.051 mm (.0020 in)

Maximum average variation between adjacent cylinders . . . 0.051 mm (.0020 in)

Maximum variation between all cylinders . . . 0.102 mm (.0040 in)

5. If the liner projections are out of specification, try rotating the liner or install the liner in another bore to see if the measurements
improve.

6. If the liner projections are all below the specifications or low in the range, 0.025 mm (.0010 in) or 0.051 mm (.0020 in), try using a
thinner spacer plate. These plates are 0.076 mm (.0030 in) thinner than the regular plate and they will increase the liner projection, thus
increasing the fire ring crush. Use these spacer plates to compensate for low liner projections that are less than 0.076 mm (.0030 in) or if
the inspection of the top deck reveals no measurable damage directly under the liner flanges, but the average liner projection is less than
0.076 mm (.0030 in).

NOTE: Do not exceed the maximum liner projection of 0.152 mm (.0060 in). Excessive liner projection will contribute to liner flange
cracking.

7. With the proper liner projection, mark the liners in the proper position and set them aside.

8. When the engine is ready for final assembly, the O-ring seals, cylinder block and upper filler band must be lubricated before installation.
Refer to the Disassembly And Assembly Manual for the proper procedure to install the cylinder liners.

Flywheel And Flywheel Housing

Face Run Out (Axial Eccentricity) Of The Flywheel Housing

If any method other than given here is used, always remember bearing clearance must be removed to get correct measurements.
8T5096 Dial Indicator Group Installed

1. Fasten a dial indicator to the crankshaft flange so the anvil of the indicator will touch the face of the flywheel housing.

2. Put a force on the crankshaft toward the rear before the indicator is read at each point.

3. With dial indicator set at 0.00 mm (.000 in) at location (A), turn the crankshaft and read the indicator at locations (B), (C) and (D).

4. The difference between lower and higher measurements taken at all four points must not be more than 0.38 mm (.015 in), which is the
maximum permissible face runout (axial eccentricity) of the flywheel housing.

Bore Runout (Radial Eccentricity) Of The Flywheel Housing

1. Fasten the dial indicator as shown so the anvil of the indicator will touch the bore of the flywheel housing.

8T5096 Dial Indicator Group Installed

2. With the dial indicator in position at (C), adjust the dial indicator to "0" (zero). Push the crankshaft up against the top of the bearing.
Write the measurement for bearing clearance on line 1 in column (C).

NOTE: Write the dial indicator measurements with their positive (+) and negative (-) notation (signs). This notation is necessary for
making the calculations in the chart correctly.

3. Divide the measurement from Step 2 by 2. Write this number on line 1 in columns (B) & (D).

4. Turn the crankshaft to put the dial indicator at (A). Adjust the dial indicator to "0" (zero).
5. Turn the crankshaft counterclockwise to put the dial indicator at (B). Write the measurement in the chart.

6. Turn the crankshaft counterclockwise to put the dial indicator at (C). Write the measurement in the chart.

7. Turn the crankshaft counterclockwise to put the dial indicator at (D). Write the measurement in the chart.

8. Add lines I & II by columns.

9. Subtract the smaller number from the larger number in line III in columns (B) & (D). The result is the horizontal eccentricity (out of
round). Line III, column (C) is the vertical eccentricity.
Graph For Total Eccentricity

(1) Total vertical eccentricity [mm(in)]. (2) Total horizontal eccentricity [mm (in)]. (3) Acceptable. (4) Not Acceptable.

10. On the graph for total eccentricity find the point of intersection of the lines for vertical eccentricity and horizontal eccentricity.

11. If the point of intersection is in the range marked "Acceptable", the bore is in alignment. If the point of intersection is in the range
marked "Not Acceptable", the flywheel housing must be changed.
Face Runout (Axial Eccentricity) Of The Flywheel

1. Install the dial indicator as shown. Always put a force on the crankshaft in the same direction before the indicator is read so the
crankshaft end clearance (movement) is always removed.

2. Set the dial indicator to read 0.0 mm (.00 in).

3. Turn the flywheel and read the indicator every 90 degrees.

4. The difference between the lower and higher measurements taken at all four points must not exceed the maximum permissible face
runout (axial eccentricity) of the flywheel, as shown in the Flywheel Specification Chart.
Checking Face Runout Of The Flywheel

Bore Runout (Radial Eccentricity) Of The Flywheel

Checking Bore Runout Of The Flywheel

(1) 7H1945 Holding Rod. (2) 7H1645 Holding Rod. (3) 7H1942 Indicator. (4) 7H1940 Universal Attachment.

1. Install the dial indicator (3) and make an adjustment of the universal attachment (4) so it makes contact as shown.

2. Set the dial indicator to read 0.0 mm (.00 in).

3. Turn the flywheel and read the indicator every 90 degrees.

4. The difference between the lower and higher measurements taken at all four points must not exceed the maximum permissible bore
runout (radial eccentricity) of the flywheel, as shown in the Flywheel Specification Chart.
Checking Flywheel Clutch Pilot Bearing Bore

5. Runout (eccentricity) of the bore for the pilot bearing for the flywheel clutch, must not exceed the maximum permissible pilot bearing
bore runout of the flywheel, as shown in the Flywheel Specification Chart.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Testing & Adjusting
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Electrical System

Test Tools For Electrical System

Most of the tests of the electrical system can be done on the engine. The wiring insulation must be in good condition, the wire and cable
connections must be clean and tight, and the battery must be fully charged. If the on-engine test shows a defect in a component, remove the
component for more testing.

The service manual Testing And Adjusting Electrical Components, REG00636 has complete specifications and procedures for the
components of the starting circuit and the charging circuit.

The 4C4911 Battery Load Tester is a portable unit in a metal case for use under field conditions and high temperatures. It can be used to
load test all 6, 8 and 12V batteries. This tester has two heavy-duty load cables that can easily be fastened to the battery terminals. A load
adjustment knob on the top permits the current being drawn from the battery to be adjusted to a maximum of 1000 amperes. The tester is
cooled by an internal fan that is automatically activated when a load is applied.

The tester has a built in LCD digital voltmeter and amperage meter. The digital voltmeter accurately measures the battery voltage at the
battery through tracer wires buried inside the load cables. The digital amperage meter accurately displays the current being drawn from the
battery under test.

NOTE: Make reference to Operating Manual, SEHS9249 for more complete information for use of the 4C4911 Battery Load Tester.

8T0900 AC/DC Clamp-On Ammeter

The 8T0900 AC/DC Clamp-On Ammeter is a completely portable, self-contained instrument that allows electrical current measurements to
be made without breaking the circuit or disturbing the insulation on conductors. A digital display is located on the ammeter for reading
current directly in a range from 1 to 1200 amperes. If an optional 6V6014 Cable is connected between this ammeter and one of the digital
multimeters, current readings of less than 1 ampere can then be read directly from the display of the multimeter.

A lever is used to open the jaws over the conductor [up to a diameter of 19 mm (.75 in)], and the spring loaded jaws are then closed around
the conductor for current measurement. A trigger switch that can be locked in the ON or OFF position is used to turn on the ammeter.
When the turn-on trigger is released, the last current reading is held on the display for 5 seconds. This allows accurate measurements to be
taken in limited access areas where the digital display is not visible to the operator. A zero control is provided for DC operation, and power
for the ammeter is supplied by batteries located inside the handle.

NOTE: Make reference to Special Instruction, SEHS8420 for more complete information for use of the 8T0900 Clamp-On Ammeter.
6V7070 Heavy-Duty Digital Multimeter

The 6V7070 Heavy-Duty Digital Multimeter is a completely portable, hand held instrument with a digital display. This multimeter is built
with extra protection against damage in field applications, and is equipped with seven functions and 29 ranges. The 6V7070 Multimeter has
an instant ohms indicator that permits continuity checks for fast circuit inspection. It also can be used for troubleshooting small value
capacitors.

NOTE: Make reference to Special Instruction, SEHS7734 for more complete information for use of the 6V7070 Multimeter.

Battery

Never disconnect any charging unit circuit or battery circuit cable from battery when
the charging unit is operated. A spark can cause an explosion from the flammable
vapor mixture of hydrogen and oxygen that is released from the electrolyte through
the battery outlets. Injury to personnel can be the result.

The battery circuit is an electrical load on the charging unit. The load is variable because of the condition of the charge in the battery.
Damage to the charging unit can result if the connections (either positive or negative) between the battery and charging unit are broken
while the charging unit is in operation. This is because the battery load is lost and there is an increase in charging voltage. High voltage can
damage, not only the charging unit, but also the regulator and other electrical components.

Use the 4C4911 Battery Load Tester, the 8T0900 Clamp-On Ammeter and the 6V7070 Multimeter to load test a battery that does not hold
a charge when in use. See Special Instruction, SEHS9249 for the correct procedure and specifications to use.

Charging System

The condition of charge in the battery at each regular inspection will show if the charging system operates correctly. An adjustment is
necessary when the battery is constantly in a low condition of charge or a large amount of water is needed (more than one ounce of water
per cell per week or per every 100 service hours).
When it is possible, make a test of the charging unit and voltage regulator on the engine, and use wiring and components that are a
permanent part of the system. Off engine (bench) testing will give a test of the charging unit and voltage regulator operation. This testing
will give an indication of needed repair. After repairs are made, again make a test to give proof that the units are repaired to their original
condition of operation.

Before the start of on engine testing, the charging system and battery must be checked as shown in the Steps that follow:

1. Battery must be at least 75 percent (1.225 Sp Gr) fully charged and held tightly in place. The battery holder must not put too much stress
on the battery.

2. Cables between the battery, starting motor and engine ground must be the correct size. Wires and cables must be free of corrosion and
have cable support clamps to prevent stress on battery connections (terminals).

3. Leads, junctions, switches, and panel instruments that have direct relation to the charging circuit must give correct circuit control.

4. Inspect the drive components for the charging unit to be sure they are free of grease and oil and have the ability to operate the charging
unit.

Alternator Regulator Adjustment

When an alternator is charging the battery too much or not enough, the charging rate of the alternator should be checked. Make reference to
the Specifications module to find all testing specifications for the alternators and regulators.

No adjustment can be made to change the rate of charge on the alternator regulators. If rate of charge is not correct, a replacement of the
regulator is necessary.

Alternator Pulley Nut Tightening

Tighten the nut that holds the pulley to the specifications given in the Specification Module.

Tools To Tighten Alternator Pulley Nut

(1) 8T9293 Torque Wrench. (2) 8S1588 Adapter (1/2 inch female to 3/8 inch male). (3) 2P8267 Socket Assembly. (4) 8H8517
Combination Wrench (11/8 inch). (5) 8T5314 Socket.

Starting System

Use the multimeter in the DCV range to find starting system components which do not function.

Move the start control switch to activate the starter solenoid. Starter solenoid operation can be heard as the pinion of the starting motor is
engaged with the ring gear on the engine flywheel.

If the solenoid for the starting motor will not operate, it is possible that the current from the battery did not get to the solenoid. Fasten one
lead of the multimeter to the connection (terminal) for the battery cable on the solenoid. Put the other lead to a good ground. A zero reading
is an indication that there is a broken circuit from the battery. More testing is necessary when there is a voltage reading on the multimeter.

The solenoid operation also closes the electric circuit to the motor. Connect one lead of the multimeter to the solenoid connection
(terminal) that is fastened to the motor. Put the other lead to a good ground. Activate the starter solenoid and look at the multimeter. A
reading of battery voltage shows the problem is in the motor. The motor must be removed for further testing. A zero reading on the
multimeter shows that the solenoid contacts do not close. This is an indication of the need for repair to the solenoid or an adjustment to be
made to the starter pinion clearance.

Make a test with one multimeter lead fastened to the connection (terminal) for the small wire at the solenoid and the other lead to the
ground. Look at the multimeter and activate the starter solenoid. A voltage reading shows that the problem is in the solenoid. A zero
reading is an indication that the problem is in the start switch or the wires for the start switch.

Fasten one multimeter lead to the start switch at the connection (terminal) for the wire from the battery. Fasten the other lead to a good
ground. A zero reading indicates a broken circuit from the battery. Make a check of the circuit breaker and wiring. If there is a voltage
reading, the problem is in the start switch or in the wires for the start switch.

A starting motor that operates too slow can have an overload because of too much friction in the engine being started. Slow operation of the
starting motor can also be caused by a short circuit, loose connections and/or dirt in the motor.

Pinion Clearance Adjustment

When the solenoid is installed, make an adjustment of the pinion clearance. The adjustment can be made with the starting motor removed.

Connection For Checking Pinion Clearance

(1) Ground terminal. (2) SW terminal. (3) Connector from Motor terminal on solenoid to motor.

1. Install the solenoid without connector (3) from the MOTOR connections (terminal) on solenoid to the motor.

2. Connect a battery, of the same voltage as the solenoid, to the terminal (2), marked SW.

3. Connect the other side of the battery to ground terminal (1).

4. Connect for a moment a wire from the solenoid connection (terminal) marked Motor to the ground connection (terminal). The pinion
will shift to crank position and will stay there until the battery is disconnected.

Pinion Clearance Adjustment

(4) Shaft nut. (5) Pinion. (6) Pinion clearance.

5. Push the pinion toward the commutator end to remove free movement.

6. Pinion clearance (6) must be 8.3 to 9.9 mm (.33 to .39 in).

7. To adjust pinion clearance, remove plug and turn nut (4).

8. After the adjustment is completed, install the plug over adjustment nut (4) and install connector (3) between the Motor terminal on the
solenoid and the starting motor.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Testing & Adjusting
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Air Starting System

Pressure Regulating Valve

Pressure Regulating Valve (Typical Illustration)

(1) Adjustment screw. (2) Regulator inlet. (3) Regulator outlet.

To check and adjust the pressure regulating valve, use the procedure that follows:

1. Drain the line to the pressure regulating valve or drain the air storage tank.

2. Disconnect the regulator from the starter control valve.

3. Connect an 8T0849 Pressure Indicator to regulator outlet (3).

4. Put air pressure in the line or tank.

5. Check the pressure.

6. Adjust the pressure regulating valve to . . . 690 to 1030 kPa (100 to 150 psi)

7. Remove the air pressure from the line or tank.

8. Remove the 8M2885 Pressure Indicator and connect the air pressure regulator to the line to the air starting motor.

Each engine application will have to be inspected to get the most acceptable starting results. Some of the factors that affect regulating valve
pressure setting are: attachment loads pulled by engine during starting, ambient temperature conditions, oil viscosity, capacity of air
reservoir, and condition of engine (new or worn).

The advantage of setting the valve at the higher pressures is increased torque for starting motor and faster rotation of engine. The advantage
of setting the valve at the lower pressures is longer time of engine rotation for a given capacity of supply air.

Lubrication

Always use an air line lubricator with these air starting motors.

For temperatures above 0°C (32°F), use a non detergent 10W engine oil.

For temperatures below 0°C (32°F), use air tool oil.

Air Starting Motor

Components Of The Air Starting Motor

(1) Motor housing cover. (2) Plug. (3) Plug. (3A) Plug. (6) Bolt (cap screw). (7) Lockwasher. (8) Gasket. (9) Rotor rear bearing. (10)
Bearing retainer. (11) Rear end plate. (12) Cylinder. (13) Dowel. (14) Rotor vane. (15) Rotor. (16) Front end plate. (17) Rotor front
bearing. (18) Motor housing. (19) Gear case gasket. (20) Rotor pinion. (21) Rotor pinion retainer. (22) Gear case. (23) Bearing rejecting
washer. (24) Rear bearing (for the drive shaft). (25) Drive gear. (25A) Thrust washer. (26) Key (for the drive gear). (27) Front bearing (for
the drive shaft). (28) Gear case cover. (29) Grease seal (for the drive shaft). (30) Cover seal. (31) Piston seal. (32) Bolt. (33) Lockwasher.
(34) Drive shaft. (35) Drive shaft collar. (36) Piston. (36A) Piston ring. (37) Shift ring. (38) Shift ring retainer. (39) Shift ring spacer. (40)
Piston return spring. (41) Return spring seat. (42) Starter drive (pinion). (43) Lockwasher. (44) Bushing (for the bolts). (45) Drive housing.
(46) Drive housing bushing. (47) Oiler felt (for the bushing). (48) Oiler plug.

Rear View Of The Cylinder And Rotor For Clockwise Rotation

(12) Cylinder. (12A) Air inlet passages. (12B) Dowel hole. (15) Rotor.
Air Starting Motor

(6) Bolt. (12) Cylinder. (15) Rotor. (16) Front end plate. (22) Gear case. (25) Drive gear. (28) Gear case cover. (29) Grease seal. (32) Bolt.
(34) Drive shaft. (35) Drive shaft collar. (42) Starter drive (pinion). (45) Drive housing. (49) Air inlet. (50) Deflector (air outlet). (51)
Mounting flange (on the drive housing).

Cylinder (12) must be assembled over rotor (15) and on front end plate (16) so dowel hole (12B) and inlet passages (12A) for the air are as
shown in the rear view illustration of the cylinder and rotor. If the installation is not correct, starter drive (42) will turn in the wrong
direction.

Tighten the bolts (6) of the rear cover in small increases of torque for all bolts until all bolts are tight 30 ± 5 N·m (22 ± 4 lb ft).

Put a thin layer of lubricant on the lip of seal (29) and on the outside of drive shaft collar (35), for installation of drive shaft (34). After
installation of the shaft through gear case cover (28) check the lip of grease seal (29). It must be turned correctly toward drive gear (25). If
the shaft turned the seal lip in the wrong direction, remove the shaft and install again. Use a tool with a thin point to turn the seal lip in the
correct direction.

Tighten bolts (32) of the drive housing in small increases of torque for all bolts until all bolts are tight 11.3 N·m (100 lb in).

Check the motor for correct operation. Connect an air hose to motor air inlet (49) and make the motor turn slowly. Look at starter drive
(42) from the front of drive housing (45). The pinion must turn clockwise.

Connect an air hose to the small hole with threads in drive housing (45), nearer gear case (22). When a little air pressure goes to the drive
housing, starter drive (42) must move forward to the engaged position. Also, the air must get out through the other hole with threads nearer
mounting flange (51).
Components Of The Air Starting Motor

(1) Motor housing cover. (2) Plug. (3) Nameplate. (4) Screw. (5) Bolt (cap screw). (6) Plug. (7) Rear end plate. (8) O-ring seal. (9) Cylinder
housing kit. (10) Dowel. (11) Front end plate. (12) O-ring seal. (13) Rotor. (14) Rear rotor bearing. (15) O-ring seal. (16) Retaining nut.
(17) Retaining nut cover. (18) Front rotor bearing. (19) Wave washers. (20) Rotor vanes. (21) Rotor pinion. (22) Bolts. (23) Gear case. (24)
O-ring seal. (25) Drive gear. (26) Drive gear bearing. (27) Retaining ring. (28) Gear case seal. (29) Retaining ring. (31) Piston kit. (32) O-
ring seal. (33) Piston bearing. (34) Retaining ring. (35) Clutch jaw kit. (36) Retaining ring. (37) Clutch springs. (38) Clutch spring cup. (39)
Piston return springs. (40) Return spring seat. (41) Drive shaft. (42) Drive shaft spacer. (43) Drive shaft washer. (44) Bolt. (45) Drive shaft
collar. (46) Drive pinion. (47) Bolt. (48) Drive housing kit. (49) Drive housing seal. (50) Drive housing bearing. (51) O-ring seal. (52)
Drive housing washer. (53) Drive housing gasket. (54) Bolts.
Air Starting Motor

(5) Bolts. (7) Rear end plate. (16) Retaining nut. (22) Bolts. (28) Gear case seal. (44) Bolt. (47) Bolt. (54) Bolts.

During assembly put two pieces of 0.10 mm (.004 in) shim stock between rotor body and rear end plate (7). Tighten retaining nut (16) until
there is a slight drag on the shim stock. Tighten the clamping screw in the retaining nut (16). The clearance between the rotor assembly and
the end plate can be 0.05 to 0.13 mm (.002 to .005 in).

Install four bolts (5), and tighten to a torque of . . . 27 N·m (20 lb ft) .

Tighten bolts (22) to a torque of . . . 68 N·m (50 lb ft) .

Install gear case seal (28) lip side first, into the small bore of the gear case. Put a thin layer of lubricant on the lip type seal and all O-ring
seals.

Install bolt (44) and tighten to a torque of . . . 75 N·m (55 lb ft) .

Install four bolts (54). Tighten to a torque of . . . 27 N·m (20 lb ft) .

Tighten the bolt (47) to a torque of . . . 75 N·m (55 lb ft) .

After assembly, turn the drive pinion by hand in the direction of starter rotation. The clutch should ratchet smoothly with a slight "clicking"
action. Attach a hose to the "IN" port and apply 345 kPa (50 psi) air pressure. The drive pinion should move outward and air will escape
from the "OUT" port. Plug the "OUT" port and apply 1034 kPa (150 psi) air pressure.

The distance measured from the face of the drive pinion to the face of the mounting flange should be 70.5 mm (2.77 in). Remove pressure
from the "IN" port. The measured distance should be 46.3 mm (1.82 in).

Connect a 9 mm (3/8 in) inlet hose at 620 kPa (90 psi). The starter should run smoothly. Plug the exhaust port and apply 207 kPa (30 psi)
air pressure. Immerse starter in a non-flammable solvent for 30 seconds. If the starter is properly sealed, no air bubbles will appear.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Testing & Adjusting
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Power Take-Off Clutch

Single Plate Clutch

Typical Illustration

4W9829

NOTE: After clutch has been installed on engine, hit output shaft sharply on the end to relieve any preload that may result due to resistance
of pilot bearing being pressed into the flywheel.

(1) Bearing Adjustment (end clearance):

Tighten nut to 41 N·m (30 lb ft) against lock to seat clutch assembly on shaft taper. Then tighten nut an additional 60 to 90 degrees. Lock in
position by bending a section of the lock against a flat on the nut.

Clutch Engagement Check (On Engine):

To adjust clutch remove instruction plate from housing and turn clutch shaft assembly until adjusting pin can be reached. Disengage
adjusting lock pin and turn adjusting ring clockwise to increase engagement torque and counterclockwise to decrease engagement torque.

A torque of 187 to 235 N·m (138 to 173 lb ft) on the splined clutch lever shaft is required to engage the clutch.

Double Plate Clutch

Typical Illustration

4P3073

NOTE: After clutch has been installed on engine, hit output shaft sharply on the end to relieve any preload that may result due to resistance
of pilot bearing being pressed into the flywheel.

(1) Bearing Adjustment (end clearance):

Tighten bearing retainer until there is no clearance between cup and cone. Back off retainer two or three notches and assemble the lock.
Strike output end of shaft to seat the inner bearing cup against the bearing retainer. The end play must be . . . 0.15 to 0.25 mm (.006 to .010
in)
Clutch Engagement Check (On Engine):

To adjust clutch remove instruction plate from housing and turn clutch shaft assembly until adjusting pin can be reached. Disengage
adjusting lock pin and turn adjusting ring clockwise to increase engagement torque and counterclockwise to decrease engagement torque.

A torque of 295 to 392 N·m (217 to 288 lb ft) on the splined clutch lever shaft is required to engage the clutch.

Triple Plate Clutch

Typical Illustration

4P3069, 4P3126, 4P3127, 1W8857, 2W4909, 2W4913, 112-1718

NOTE: After clutch has been installed on engine, hit output shaft sharply on the end to relieve any preload that may result due to resistance
of pilot bearing being pressed into the flywheel.

(1) Bearing Adjustment (end clearance):

Tighten bearing retainer until there is no clearance between cup and cone. Back off retainer two or three notches and assemble the lock.
Strike output end of shaft to seat the inner bearing cup against the bearing retainer. The end play must be . . . 0.15 to 0.25 mm (.006 to .010
in)

Clutch Engagement Check (On Engine):

To adjust clutch remove instruction plate from housing and turn clutch shaft assembly until adjusting pin can be reached. Disengage
adjusting lock pin and turn adjusting ring clockwise to increase engagement torque and counterclockwise to decrease engagement torque.

4P3069, 4P3126, 112-1718

A torque of 772 to 1018 N·m (568 to 749 lb ft) on the splined clutch lever shaft is required to engage the clutch.

4P3127, 1W8857

A torque of 295 to 392 N·m (217 to 288 lb ft) on the splined clutch lever shaft is required to engage the clutch.

2W4909

A torque of 325 to 435 N·m (239 to 320 lb ft) on the splined clutch lever shaft is required to engage the clutch.

2W4913

A torque of 697 to 917 N·m (513 to 674 lb ft) on the splined clutch lever shaft is required to engage the clutch.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Testing & Adjusting
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Instruments And Indicators

Magnetic Pickup

Typical Illustration

(1) Clearance between magnetic pickup and flywheel ring gear . . . 0.55 to 0.83 mm (0.022 to .033 in)

NOTE: Turn the pickup in until it comes in contact with the teeth on the flywheel ring gear. Turn the pickup out 1/2 turn. This will give
0.55 to 0.83 mm (.022 to .033 in) clearance at (1).

(2) Tighten the locknut to a torque of . . . 45 ± 7 N·m (33 ± 5 lb ft)

Oil Pressure Sending Unit

Sending Unit For Oil Pressure

(1) Terminal. (2) Fitting.

1. Connect the sending unit to a pressure source that can be measured with accuracy.

2. Connect an ohmmeter between fitting (2) and terminal (1).

3. Take resistance readings at the pressures shown in the chart.

4. If a unit does not have the correct resistance readings, make a replacement of the unit.

Water Temperature Sending Unit

Sending Unit For Water Temperature

(1) Terminal. (2) Nut. (3) Bulb.

1. Connect an ohmmeter between terminal (1) and nut (2). Put bulb (3) in a pan of water. Do not let the bulb have contact with the pan.

2. Put a thermometer in the water to measure the temperature.

3. Take a resistance reading at the temperatures shown in the chart.

4. If a unit does not have the correct resistance readings, make a replacement of the unit.

Electric Indicators

1. Put the indicator in position with the letters horizontal and the face 30 degrees back from vertical.
Wiring Diagram For Test

(1) Terminal (for test voltage). (2) Test resistance.

2. Connect the indicator in series with the power source and the middle test resistance shown in the chart.

3. Let the indicator heat at the middle resistance for five minutes, then check the pointer position for all of the resistance given.

Mechanical Indicators For Temperature

Direct Reading Indicator

To check these indicators, put the bulb of the indicator in a pan of oil. Do not let the bulb touch the pan. Put a thermometer in the oil to
measure the temperature. Make a comparison of temperatures on the thermometer with the temperatures on the direct reading indicator.

Mechanical Indicators For Pressure

Direct Reading Indicator

To check these indicators connect the indicator to a pressure source that can be measured with accuracy. Make a comparison of pressure on
the indicator of test equipment with the pressures on the direct reading indicator.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Testing & Adjusting
Media Number SENR1137-01 Publication Date 1998/02/17 Update Date 1998/03/24

Shutoff Solenoids

Rack Solenoid

(1) Travel. (2) Distance between shaft and plate. (3) Start position of plunger plate from mounting flange.

7E7143

5N8293

1W1223

2W6665

NOTE: Refer to Specifications, 3408C & 3412C Industrial Engines, SENR1136 for the proper dimensions shown.

Two checks must be made on the engine to give proof that the solenoid adjustment is correct.
1. The adjustment must give the plunger enough travel to move the rack to the fuel shutoff position. Use the 6V9128 Rack Position Tool
Group to make sure the rack goes to the fuel shutoff position.

2. The adjustment must give the plunger enough travel to cause only the "hold-in" windings of the solenoid to be activated when the rack is
held in the fuel shutoff position. Use a thirty ampere ammeter to make sure the plunger is in the "hold-in" position. Current needed must be
less than two amperes.

Rack Solenoid

(1) Solenoid plunger. (2) Stop bolt. (3) Locknut. (4) Lock wire and seal.

4P0303

7W7787

1. Remove any manual shutoff shaft linkage from the governor.

2. Remove lock wire and seal (4). Loosen locknut (3) and turn stop bolt (2) several turns out [away from solenoid plunger (1)].
3. Rotate the manual shutoff shaft clockwise to the shutoff position. Fasten the shaft in the shutoff position.

4. Hold locknut (3) and turn stop bolt (2) in until the bolt contacts shutoff solenoid plunger (1).

5. Turn stop bolt (2) in an additional 3/4 ± 1/4 turn and tighten locknut (3).

6. Release the manual shutoff shaft.

7. Start the engine.

8. The engine should run at low idle without a problem.

9. To test the solenoid stop bolt adjustment, run the engine at high idle and no load. Shut off the engine and the engine should stop.

10. If the engine continues to run at reduced speed or shuts down too slowly, turn the stop bolt (2) out an additional 1/4 turn and repeat Step
9.

11. If possible, apply a load to the engine and make sure the engine will maintain the normal full load speed. Remove the load and return
the engine to low idle.

12. Shut off the engine.

13. Install a new lock wire and seal (4).

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Operation & Maintenance
Media Number SEBU6945-00 Publication Date 1995/09/07 Update Date 2002/02/07

Maintenance Interval Schedule ( 3412 Industrial Engine)

SMCS Code: 7500; 7520; 7524; 7526; 7545

Note: Make sure you read and understand the Safety Information, warnings and instructi ons before performing any operation or
maintenance procedures.

Before each consecutive interval is performed, all of the maintenance requirements from the previous interval must also be
performed.

Daily

Walk-Around Inspection

Inspect the Engine for Leaks and for Loose Connections

Engine Crankcase

Check Oil Level

Cooling System Level

Check Coolant Level

Engine Air Cleaner

Engine Air Cleaner Indicator

Test Service Indicator

Air Starter Motor

Checking and Filling the Oiler Bowl

Adjusting Oiler Feed

Air Tank

Driven Equipment

Inspect the Alignment

Every 9,500 L ( (2,500 gal)) of Fuel or 125 Hours

PTO Main Shaft, Shift Lever and Pilot Bearings

Lubrication

Every 19,000 L ( (5,000 gal)) of Fuel or 250 Hours

Scheduled Oil Sampling (S·O·S)

Obtain a Sample
Engine Oil and Filters

Drain the Oil

Change the Filters

Fuel System

Drain Water and Sediment from the Fuel Tank

Cleaning and Replacing of the Fuel Filters

Coolant Additive Concentration Test

Test for Supplemental Coolant Additive Concentration

Replacing the Coolant Additive Element (If Equipped)

Adding the Supplemental Coolant Additive

Coolant Analysis

Obtaining the Coolant Sample

Crankcase Breather

Clean

Battery

Clean the Terminals and Tighten the Terminals

Check the Electrolyte Level

Belts, Hoses and Clamps

Inspection and Replacement of the Alternator Belts and the Fan Drive Belts

Inspection and Replacement of Hoses and of Clamps

Clutch

Check/Adjust

Lubrication

Engine Valve Lash

Adjustment of the Bridges

Adjustment of the Valve Lash

Fan Drive

Lubricate the Bearings

Every 76,000 L ( (20,000 gal)) of Fuel or 1,000 Hours

Engine Protection Devices

Inspect the Engine Protection Devices for Proper Operation

Verify the Operation for the Alarm and for the Shutdown

Turbochargers

Inspect the Turbocharger for Proper Operation

Every 227,500 L ( (60,000 gal)) of Fuel or 3,000 Hours or Two Years

Cooling System Clean/Flush

Draining, Cleaning, and Replacement of Coolant

Engine Mounts and Crankshaft Vibration Damper

Inspect the Engine Mounts

Inspect the Vibration Damper

Thermostats

Replacement of Thermostats, of Gaskets, and of Seals

Extender for Long Life Coolant/Antifreeze

Addition of Extender

Fuel Ratio Control and Low Idle

Adjustments

Engine Valve Lash

Adjustment of the Bridges

Adjustment of the Valve Lash

Valve Rotators

Observe the Valve Rotators

Every 379,000 L ( (100,000 gal)) of Fuel or 5,000 Hours

Fuel Injection Nozzles

The Fuel Injection Nozzles are Tested and/or Exchanged

Alternators

Inspection for Proper Operation

 Caterpillar Recommendation

Removal and Installation

Water Pump

Rebuild the Water Pump or Exchange the Water Pump

Caterpillar Recommendation

Starter Motors

Inspection for Proper Operation

Removal and Installation

Turbochargers

Inspect the Turbocharger for Proper Operation

Turbocharger Maintenance

Rebuild or Exchange of the Turbocharger

Caterpillar Recommendation

Overspeed Shutoff

Test the Proper Operation of Overspeed Shutoff

Procedure to Check Overspeed Shutoff

Every 4 Years

Long Life Coolant/Antifreeze

Cleaning, Flushing, and Replacing of the Long Life Coolant/Antifreeze

Flush

Fill

Overhaul

Top End Overhaul

Top End Overhaul

Complete Overhaul

Overhaul Programs

Overhaul Options

Overhaul Recommendation
 Overhaul Instructions

Coolant Analysis

After Failure Overhaul

After Failure Overhaul

Caterpillar Recommendation

81Z

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Operation & Maintenance
Media Number SEBU6945-00 Publication Date 1995/09/07 Update Date 2002/02/07

Engine Valve Lash

SMCS Code: 1105

Adjustment of the Bridges

Perform the inspection and the adjustments to the valve bridge at the same time that you perform the inspection and the adjustments of the
valve lash. The valve and the valve mechanism components do not always wear evenly. Uneven wear can allow the bridge to go out of
adjustment. Abnormal wear rates between valves will result in improperly adjusted bridges as a result of uneven wear of valve mechanism
components.

There are two rocker arms per cylinder. One rocker arm is for the two exhaust valves and one rocker arm is for the two inlet valves. Each
pair of valves is connected by a bridge. This bridge is actuated by the rocker arm. The valves in each pair are adjusted simultaneously by
the adjusting screw that is in the rocker arm. Each bridge is adjusted by the adjusting screw.

Be sure to adjust the valve bridges before checking valve lash. See Valve Bridge
adjustment in the Service Manual for the procedure.

Perform the procedure for both bridges for each cylinder. Put clean engine oil on the contact points of both bridges and in the bridge bores.

It is not necessary to remove the rocker arm shaft in order to adjust the valve bridges, but there must be lash. Push down on the top of the
rocker arm directly above the center of the bridge in order to check bridge adjustment. Refer to the Service Manual for your engine for the
complete adjustment procedure.

With the stopped, cold engine, inspect the bridge adjustment and the valve adjustment and perform any necessary adjustments. Before
adjusting valve lash, a bridge adjustment must be performed. After checking the bridge adjustment for each cylinder, proceed with the
valve lash adjustment, if necessary.

Adjustment of the Valve Lash

To prevent possible injury, do not use the starting motor to turn the flywheel. Be sure
the starting motors are disabled and engine cannot be started while this maintenance
is being performed. Hot engine components can cause burns. Allow additional time for
the engine to cool before measuring valve lash.

Initial valve lash adjustments are performed at the first oil change interval or at the 250 Service Hour interval on new engines, on rebuilt
engines or on remanufactured engines. This is recommended due to initial wear and to seating of the valve train components. All
subsequent adjustments should be performed at the 3000 Service Hour interval.
 Table 36

Valve Lash Setting

Valve Setting

Intake 0.38 mm (.015 inch)

Exhaust 0.76 mm (.030 inch)

This maintenance is recommended as a portion of the lubrication and preventive maintenance schedule. By performing the necessary
adjustments of the valve lash at the required intervals, maximum engine life will be provided.

Setting the valve lash on Caterpillar engines should be performed when the engine is cold. After the engine is shut down and after the valve
covers are removed, the engine is considered cold.

Table 37

Crankshaft Positions For Valve Lash Setting

Check and/or Adjust With No. 1 Piston on Top Center position: (1)

Top Center position for No. 1 Piston Top Center position for No. 11 Piston

3412 Engine Compression Stroke Compression Stroke

The SAE Standard Rotation Engine is counterclockwise when the rotation is viewed from the Flywheel End.

Intake Valves 1, 3, 4, 6, 7, 12 2, 5, 8, 9, 10, 11

Exhaust Valves 1, 4, 5, 8, 9, 12 2, 3, 6, 7, 10, 11

(1) Refer to the Service Manual for the complete procedure.

Illustration 56

No. 1 Piston at Top Center position on compression stroke

 Illustration 57

No. 11 Piston at Top Center position on compression stroke

Thoroughly clean the area around the valve mechanism covers. This prevents foreign matter from entering into the top of the cylinder head
and from entering into the valve mechanism.

Refer to the Service Manual for your engine or to your Caterpillar dealer for the complete valve adjustment procedure.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Introduction

When the words "use again" are in the description, the specification given can be used to determine if a part can be used again. If the part is
equal to or within the specification given, use the part again.

When the word "permissible" is in the description, the specification given is the "maximum or minimum" tolerance permitted before
adjustment, repair and/or new parts are needed.

A comparison can be made between the measurements of a worn part and the specifications of a new part to find the amount of wear. A
part that is worn can be returned to service if an estimate of the remainder of its service life is good. If a short service life is expected,
replace the part.

REFERENCE: See 3408C & 3412C Industrial Engines, SENR1137, for Systems Operation, Testing & Adjusting.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Engine Design

3408C

Cylinder, Valve And Injection Pump Location

Number And Arrangement Of Cylinders . . . 65 degree V-8

Valves Per Cylinder . . . 4

Displacement . . . 18.0 liters (1099 cu in)

Bore . . . 137.2 mm (5.40 in)

Stroke . . . 152.4 mm (6.00 in)

Compression Ratio . . . 14.5:1

Type Of Combustion . . . Direct Injection

Direction Of Crankshaft Rotation (as viewed from flywheel end) . . . Counterclockwise

Direction Of Fuel Pump Camshaft Rotation (as viewed from pump drive end) . . . Counterclockwise

Firing Order (Injection Sequence) . . . 1-8-4-3-6-5-7-2

Valve Lash Setting

Inlet . . . 0.38 mm (.015 in)

Exhaust . . . 0.76 mm (.030 in)

NOTE: Front end of engine is opposite the flywheel end. Left side and right side of engine are as viewed from the flywheel end. No. 1
cylinder is the front cylinder on the left side. No. 2 cylinder is the front cylinder on the right side.

3412C

Cylinder, Valve And Injection Pump Location

Number And Arrangement Of Cylinders . . . 65 degree V-12

Valves Per Cylinder . . . 4

Displacement . . . 27.0 liters (1649 cu in)

Bore . . . 137.2 mm (5.40 in)

Stroke . . . 152.4 mm (6.00 in)

Compression Ratio . . . 14.5:1

Type Of Combustion . . . Direct Injection

Direction Of Crankshaft Rotation (as viewed from flywheel end) . . . Counterclockwise

Direction Of Fuel Pump Camshaft Rotation (as viewed from pump drive end) . . . Counterclockwise

Firing Order (Injection Sequence) . . . 1-4-9-8-5-2-11-10-3-6-7-12

Valve Lash Setting

Inlet . . . 0.38 mm (.015 in)

Exhaust . . . 0.76 mm (.030 in)

NOTE: Front end of engine is opposite the flywheel end. Left side and right side of engine are as viewed from the flywheel end. No. 1
cylinder is the front cylinder on the left side. No. 2 cylinder is the front cylinder on the right side.
Copyright 1991, 2004 Caterpillar Inc.
All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Fuel System Identification

Fuel Injection Pump And Governor Group (3412C Shown)

(1) Location of stamped part number, change number, combustion type and identification number.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Fuel Injection Lines

3408C

(1) Tighten fuel line nuts to a torque of . . . 40 ± 7 N·m (30 ± 5 lb ft)

(2) Tighten bolts to a torque of . . . 55 ± 10 N·m (40 ± 7 lb ft)

(3) Torque for locknut that holds the inner fuel line to the valve cover base . . . 30 ± 7 N·m (22 ± 5 lb ft)

(4) Torque for nozzle retainer on nozzle adapter . . . 48 ± 7 N·m (35 ± 5 lb ft)

Be sure the fuel injection line clamps are installed in the correct locations. Incorrectly
installed clamps may allow the fuel injection lines to vibrate and become damaged.
The damaged lines may leak and cause a fire.

Align brackets in position to fuel lines such that when the fasteners are tightened no strain will be added to the fuel lines while tightening
fasteners.

(1) Clamp location dimensions are in reference to a line (1) through the center of the No. 1 and No. 4 fuel pump outlets.

(A) . . . 288 ± 7 mm (11.3 ± .3 in)

(B) . . . 205 ± 7 mm (8.1 ± .3 in)

(C) . . . 190 ± 7 mm (7.5 ± .3 in)

(D) . . . 168 ± 7 mm (6.6 ± .3 in)

(E) . . . 259 ± 3 mm (10.2 ± .1 in)

(2) Clamp location dimensions are in reference to a line (2) through the center of the No. 1 and No. 8 fuel pump outlets.

(F) . . . 60 ± 5 mm (2.4 ± .2 in)

(G) . . . 23 ± 3 mm (.9 ± .1 in)

(H) . . . 211 ± 5 mm (8.3 ± .2 in)

NOTE: The 6V4980 Torque Screwdriver Tool Group is available for applying the correct torque.

3412C

Typical Illustration
Typical Illustration

(1) Torque for nuts that hold the fuel injection lines to the injection pumps and nozzles . . . 40 ± 7 N·m (30 ± 5 lb ft)

(2) Tighten four bolts to a torque of . . . 55 ± 10 N·m (40 ± 7 lb ft)

(3) Torque for locknut that holds the inner fuel line to the valve cover base . . . 30 ± 7 N·m (22 ± 5 lb ft)

(4) Torque for nozzle retainer on nozzle adapter . . . 48 ± 7 N·m (35 ± 5 lb ft)
 Be sure the fuel injection line clamps are installed in the correct locations. Incorrectly
installed clamps may allow the fuel injection lines to vibrate and become damaged.
The damaged lines may leak and cause a fire.

Align brackets in position to fuel lines such that when the fasteners are tightened no strain will be added to the fuel lines while tightening
fasteners.

(1) Clamp location dimensions are in reference to a line (1) through the center of the No. 1 and No. 8 fuel pump outlets.

(A) . . . 177 ± 3 mm (7.0 ± .1 in)

(B) . . . 200 ± 3 mm (7.9 ± .1 in)

(C) . . . 225 ± 3 mm (8.9 ± .1 in)

(D) . . . 295 ± 3 mm (11.6 ± .1 in)

(E) . . . 312 ± 3 mm (12.3 ± .1 in)

(F) . . . 380 ± 3 mm (15.0 ± .1 in)

(G) . . . 403 ± 3 mm (15.7 ± .1 in)

(H) . . . 544 ± 16 mm (21.4 ± .6 in)

(J) . . . 763 ± 65 mm (30.0 ± 2.6 in)

(K) . . . 92 ± 3 mm (3.6 ± .1 in)

(L) . . . 210 ± 3 mm (8.7 ± .1 in)

(M) . . . 233 ± 3 mm (9.2 ± .1 in)

(N) . . . 320 ± 3 mm (12.6 ± .1 in)

(O) . . . 400 ± 3 mm (15.7 ± .1 in)

(P) . . . 601.3 mm (23.70 in)

(Q) . . . 738.3 mm (29.10 in)

(2) Clamp location dimensions are in reference to a line (2) through the center of the No. 1 and No. 11 fuel pump outlets.

(R) . . . 18.5 ± 3.0 mm (.70 ± .10 in)

(3) Clamp location dimensions are in reference to a line (3) through the center of the No. 8 and No. 6 fuel pump outlets.

(S) . . . 45 ± 3 mm (1.8 ± .1 in)

(T) . . . 23.8 mm (.90 in)

NOTE: The 6V4980 Torque Screwdriver Tool Group is available for applying the correct torque.

Double Wall
Typical Illustration (3408C Shown)

(1) Tighten the studs for the locks to a torque of . . . 15 ± 5 N·m (11 ± 4 lb ft)

(2) Torque for all bolts that hold the fuel injection line clamps . . . 9.5 ± 2.8 N·m (84 ± 25 lb in)

(3) Torque for the nuts that hold the fuel injection lines to the injection pumps . . . 40 ± 7 N·m (30 ± 5 lb ft)

(4) Torque for nuts that hold the fuel injection lines to the adapter . . . 40 ± 7 N·m (30 ± 5 lb ft)

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Fuel Injection Nozzle And Adapter

(1) Torque for fuel injection line nut . . . 40 ± 7 N·m (30 ± 5 lb ft)

(2) Torque for retainer . . . 48 ± 7 N·m (35 ± 5 lb ft)

(3) Tighten bleed screw to a torque of . . . 2.7 ± 0.8 N·m (24 ± 7 lb in)

Always use a new washer (seal) anytime the bleed screw is removed.

(4) Washer. Make sure the correct washer is used when the nozzle assembly is installed.

(5) Put liquid soap on the rubber O-ring seal and in the bore in the head before assembly.
(6) Put 5P3931 Anti-Seize Compound on the threads of the adapter before installation. Torque for the adapter . . . 205 ± 14 N·m (150 ± 10
lb ft)

See Testing & Adjusting section, for fuel injection nozzle test procedure.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Fuel Injection Pump

Injection timing before TC (top center):

3408C . . . 25 degrees

3412C . . . 30 degrees

NOTE: For the correct timing specifications for the adjustment of the fuel injection pump groups not listed, refer to Engine Information
Plate, TMI (Technical Marketing Information), or Fuel Setting And Related Information Fiche.

(1) Torque for bushing . . . 163 ± 14 N·m (120 ± 10 lb ft)

(2) Springs:

8N1415 Spring (Outer):

Length under test force . . . 8.69 mm (.342 in)

Test force . . . 111.0 ± 6.0 N (24.94 ± 1.35 lb)

Free length after test . . . 12.12 mm (.477 in)

Outside diameter . . . 9.78 mm (.385 in)

1W6985 Spring (Inner)

Length under test force . . . 7.63 mm (.300 in)

Test force . . . 8.3 ± 0.8 N (1.87 ± .18 lb)

Free length after test . . . 8.54 mm (.336 in)

Outside diameter . . . 3.2 mm (.13 in)

(3) Thickness of spacers:

9N6496 Spacer . . . 4.12 mm (.162 in)

9N6495 Spacer . . . 4.22 mm (.166 in)

5M2697 Spacer . . . 4.32 mm (.170 in)

2M4208 Spacer . . . 4.42 mm (.174 in)

2M4209 Spacer . . . 4.52 mm (.178 in)

2M4210 Spacer . . . 4.62 mm (.182 in)

2M4211 Spacer . . . 4.72 mm (.186 in)

2M4212 Spacer . . . 4.83 mm (.190 in)

5M2691 Spacer . . . 4.93 mm (.194 in)

5S7189 Spacer . . . 5.03 mm (.198 in)

(4) 7N1208 Lifter Spring:

Length under test force . . . 29.26 mm (1.152 in)

Test Force . . . 325.0 ± 16.0 N (73.03 ± 3.60 lb)

Free length after test . . . 48.03 mm (1.891 in)

Outside diameter . . . 25.27 mm (.995 in)

(5) Length of pump plunger (new) . . . 69.118 ± 0.013 mm (2.7212 ± .0005 in)

Minimum permissible length (worn) . . . 69.080 mm (2.7197 in)

(6) Bores for the racks:

Bore in housing, at the rear (new) . . . 12.758 ± 0.038 mm (.5023 ± .0015 in)

Bearing at the front (new) . . . 12.758 ± 0.046 mm (.5023 ± .0018 in)

Diameter of fuel racks (new) . . . 12.662 ± 0.005 mm (.4985 ± .0002 in)

Maximum permissible clearance between rack and bearings (worn) . . . 0.18 mm (.007 in)

(7) Bore in bearings for the camshaft (new) . . . 53.988 ± 0.038 mm (2.1255 ± .0005 in)
Diameter of bearing surfaces of the camshaft (new) . . . 53.899 ± 0.013 mm (2.1220 ± .0005 in)

Maximum permissible clearance between the bearings and the camshaft . . . 0.25 mm (.010 in)

5P4158 Gauge

(8) On engine timing dimension for the fuel injection pumps, with 5P4158 Gauge (A):

3408C . . . 106.486 ± 0.051 mm (4.1924 ± .0020 in)

3412C . . . 105.710 ± 0.051 mm (4.1618 ± .0020 in)

NOTE: Use spacer as required to obtain dimension (8).

(9) Tighten valve assembly to a torque of . . . 70 ± 14 N·m (50 ± 10 lb ft)

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Fuel Injection Pump Housing

3408C

(1) Install pin to get a dimension of . . . 4.78 ± 0.25 mm (.188 ± .010 in)

(2) Install dowel to get a dimension of . . . 12.19 ± 0.25 mm (.480 ± .010 in)

(3) Rack bearing alignment-the center of the rack bearing tab must be within 0.05 mm (.002 in) of a vertical line that:

(a) goes through the center of the rack bearing

(b) is parallel to the vertical centerline of injection pump housing

NOTE: The following tooling is available to position the rack bearings correctly: 5P6217 Fixture and 5P6218 Driver.

The correct bearing depth [19.0 ± 0.5 mm (.75 ± .02 in)] is controlled when driver is stopped by fixture.

(4) Position of camshaft bearing joints (X) must be limited to area (A) . . . 30 ± 1 degrees

NOTE: When viewed from the Front (View A-A) of the injection pump housing, the two camshaft bearings must be installed with the
bearing joint (X) in an area (A) between a vertical position and a position 30 degrees to the Right of vertical. At the same time, oil hole (Y)
in the two bearings must be to the Left of vertical.

(5) Install dowel to a dimension of . . . 9.7 ± 0.5 mm (.38 ± .02 in)

(6) Distance from bottom of housing to end of rear hollow dowel . . . 1.5 ± 0.3 mm (.06 ± .01 in)

(7) Maximum distance from bottom of housing to end of front hollow dowel . . . 1.0 mm (.04 in)

(8) Torque for bolts . . . 55 ± 7 N·m (40 ± 5 lb ft)

(9) Distance from rear bearing bore face to installed rear camshaft bearing . . . 4.8 ± 0.5 mm (.19 ± .02 in)

(10) Distance from front bearing bore face to installed front camshaft bearing . . . 1.0 ± 0.5 mm (.04 ± .02 in)

(11) Install dowel to a dimension of . . . 16.8 ± 0.5 mm (0.66 ± 0.02 in)

(12) Distance from top surface of housing to top of lower governor drive bearing . . . 28.4 ± 0.5 mm (1.12 ± .02 in)

(13) Position the top governor drive bearing (notch end up) with the notch in alignment with the center of oil hole (Z). A line drawn
through the center of the notch and hole (Z) should make an angle (U) of 10 ± 5 degrees with centerline (W) as shown. Install the bearing
even with the top surface of the housing . . . +0.00 to -0.15 mm (+.000 to -.006 in)

(14) Install dowel to get a dimension from centerline of fuel injection pump bore to dowel (seal dowel hole with aluminum ball) . . . 14.76
± 0.10 mm (.581 ± .004 in)

(15) Distance from end of plug to face of housing . . . 1.25 ± 0.25 mm (.049 ± .010 in)

(16) End of plug to be even with outside face of housing.

(17) Install pins until they contact bottom of housing casting.

3412C
(1) Install pin to get a dimension of . . . 4.78 ± 0.25 mm (.188 ± .010 in)

(2) Install dowel to get a dimension of . . . 12.19 ± 0.25 mm (.480 ± .010 in)

(3) Rack bearing alignment. The center of the rack bearing tab must be within 0.05 mm (.002 in) of a vertical line that:

(a) goes through the center of the rack bearing

(b) is parallel to the vertical centerline of injection pump housing

NOTE: The following tooling is available to position the rack bearings correctly: 5P6217 Fixture and 5P6218 Driver.

The correct bearing depth [19.1 ± 0.5 mm (.75 ± .02 in)] is controlled when driver is stopped by fixture.

(4) Position of camshaft bearing joints (X) must be limited to area (A) . . . 30 ± 1 degree

NOTE: When viewed from the Front of the injection pump housing, all three camshaft bearings must be installed with the bearing joint
(X) in an area (A) between a vertical position and a position 30 degrees to the Right of vertical. At the same time, oil hole (Y) in the two
end bearings (center bearing has no oil hole) must be to the Left of vertical.

(5) Install dowels to get a dimension of . . . 9.7 ± 0.5 mm (.38 ± .02 in)

(6) Distance from bottom of housing to end of rear hollow dowel . . . 1.5 ± 0.3 mm (.06 ± .01 in)

(7) Maximum distance from bottom of housing to end of front hollow dowel . . . 1.0 mm (.04 in)

(8) Torque for bolts . . . 55 ± 7 N·m (40 ± 5 lb ft)

(9) Distance from rear bearing bore face to installed rear camshaft bearing . . . 4.8 ± 0.5 mm (.19 ± .02 in)

(10) Distance from rear bearing bore face to installed center camshaft bearing . . . 127.0 ± 0.5 mm (5.00 ± .02 in)

(11) Distance from front bearing bore face to installed front camshaft bearing . . . 1.0 ± 0.5 mm (.04 ± .02 in)

(12) Install plug to a depth of . . . 1.3 ± 0.5 mm (.05 ± .02 in)

(13) Pressure oil passage.

(14) Install pins until they contact bottom of housing casting.

(15) Distance from top surface of housing to top of lower governor drive bearing . . . 28.4 ± 0.5 mm (1.12 ± .02 in)

(16) Position the top governor drive bearing (notch end up) with the notch in alignment with the center of oil hole (Z). A line drawn
through the center of the notch and hole (Z) should make an angle (U) of 10 ± 5 degrees with centerline (W) as shown. Install the bearing
even with the top surface of the housing . . . +0.00 to -0.15 mm (+.000 to -.006 in)

(17) Install dowel to get a dimension from centerline of fuel injection pump bore to dowel (seal dowel holes with aluminum ball) . . . 14.76
± 0.10 mm (.581 ± .004 in)

(18) Distance from end of plug to face of housing . . . 1.25 ± 0.25 mm (.049 ± .010 in)

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Governor

NOTE: Any adjustment to the governor must be made only by a person approved by Caterpillar or by a Caterpillar Dealer.

(1) Torque for nut . . . 12 ± 4 N·m (9 ± 3 lb ft)

(2) 6N8793 Spring:

Length under test force . . . 19.05 mm (.750 in)

Test force . . . 2.0 ± 0.1 N (.45 ± .03 lb)

Free length after test . . . 41.9 mm (1.65 in)

Outside diameter . . . 9.40 mm (.370 in)

Install Spring Washers As Shown

(3) Seat. Install a spring washer, flat washer and spring washer between seat (3) and spring (4) as shown.

(4) 9L6447 Spring for the governor:

Color code (stripes) . . . one brown, one red

Put force on spring of . . . 18.0 N (4.00 lb)

Then add more force to make spring shorter by . . . 22.86 mm (.900 in)

Total test force . . . 69.9 ± 1.3 N (15.70 ± .30 lb)

Free length after test . . . 56.9 ± 0.8 mm (2.24 ± .03 in)

Outside diameter . . . 35.3 mm (1.39 in)

(4) 9L6449 Spring for the governor:

Color code (stripes) . . . one green, one brown

Put force on spring of . . . 22.3 N (5.00 lb)

Then add more force to make spring shorter by . . . 22.86 mm (.900 in)
Total test force . . . 86.6 ± 1.8 N (19.46 ± .40 lb)

Free length after test . . . 56.9 ± 1 mm (2.24 ± .04 in)

Outside diameter . . . 35.2 mm (1.39 in)

(4) 9L6448 Spring for the governor:

Color code . . . one green stripe, one yellow stripe

Put force on spring of . . . 22.2 N (5.00 lb)

Then add more force to make spring shorter by . . . 22.86 mm (.900 in)

Total test force . . . 73.0 ± 1.5 N (16.60 ± .34 lb)

Free length after test . . . 56.9 ± 0.8 mm (2.24 ± .03 in)

Outside diameter . . . 35.3 mm (1.39 in)

(4) 9L6446 Spring for the governor:

Color code . . . one green stripe, one blue stripe

Put force on spring of . . . 17.8 N (4.00 lb)

Then add more force to make spring shorter by . . . 20.32 mm (.800 in)

Total test force . . . 55.2 ± 1.1 N (12.40 ± .24 lb)

Free length after test . . . 56.9 ± 1.0 mm (2.24 ± .04 in)

Outside diameter . . . 34.8 mm (1.37 in)

(4) 8L9790 Spring for the governor:

Color code . . . one end pink

Put force on spring of . . . 17.8 N (4.00 lb)

Then add more force to make spring shorter by . . . 22.86 mm (.900 in)

Total test force . . . 59.9 ± 1.2 N (13.45 ± .27 lb)

Free length after test . . . 59.4 ± 1.0 mm (2.34 ± .04 in)

Outside diameter . . . 35.1 mm (1.38 in)

(4) 8N1312 Spring for the governor:

Color code . . . three white stripes

Put force on spring of . . . 13.4 N (3.00 lb)

Then add more force to make spring shorter by . . . 20.00 mm (.787 in)
Total test force . . . 41.4 ± 1.2 N (9.30 ± .28 lb)

Free length after test . . . 57.0 ± 1.0 mm (2.20 ± .04 in)

Outside diameter . . . 34.6 mm (1.36 in)

(4) 8N1310 Spring for the governor:

Color code . . . two green stripes

Put force on spring of . . . 13.4 N (3.00 lb)

Then add more force to make spring shorter by . . . 20.00 mm (.787 in)

Total test force . . . 36.1 ± 1.1 N (8.12 ± .24 lb)

Free length after test . . . 57.0 ± 1.0 mm (2.20 ± .04 in)

Outside diameter . . . 34.3 mm (1.35 in)

(4) 8N1309 Spring for the governor:

Color code . . . one white stripe, one yellow stripe

Put force on spring of . . . 13.4 N (3.00 lb)

Then add more force to make spring shorter by . . . 20.00 mm (.787 in)

Total test force . . . 34.4 ± 1.0 N (7.72 ± .23 lb)

Free length after test . . . 57.0 ± 1.0 mm (2.20 ± .04 in)

Outside diameter . . . 34.3 mm (1.35 in)

(4) 1W1635 Spring for the governor:

Color code . . . one blue stripe, one red stripe

Put force on spring of . . . 22.2 N (5.00 lb)

Then add more force to make spring shorter by . . . 25.40 N (5.707 lb)

Total test force . . . 53.4 ± .9 N (12.00 ± .20 lb)

Free length after test . . . 68.6 ± .8 mm (2.70 ± .03 in)

Outside diameter . . . 34.7 mm (1.37 in)

(5) 9M6303 Spring:

Length under test force . . . 4.57 mm (.180 in)

Test force . . . 45.0 ± 4.0 N (10.11 ± .90 lb)

Free length after test . . . 8.74 mm (.344 in)

Outside diameter . . . 12.19 mm (.480 in)

(6) Diameter of the outer surface of the cylinder (new) . . . 38.100 ± 0.013 mm (1.5000 ± .0005 in)

Bore in the gear (new) . . . 38.151 ± 0.013 (1.5020 ± .0005 in)

(7) Put marks in alignment on pinion-stop and gear before installing dowel.

(8) Bore in the bearing (new) . . . 22.263 ± 0.038 mm (.8765 ± .0015 in)

Diameter of the gear at the hub (new) . . . 22.187 ± 0.013 mm (.8735 ± .0005 in)

(9) Distance from the face of the plate to the bearing for the governor drive assembly . . . 0.51 ± 0.25 mm (.020 ± .010 in)

(10) Dowel installation:

Angle A must be . . . 54 ± 10 degrees

Dimension B must be . . . 7.9 ± 0.5 mm (.31 ± .02 in)

(11) Install dowels to get a dimension of . . . 5.6 ± 0.5 mm (.22 ± .02 in)
Control Shaft Bearings

(12) Bore in the governor control shaft bearings (after assembly) . . . 15.761 ± 0.038 mm (.6205 ± .0015 in)

Diameter of the governor control shaft (new) . . . 15.720 ± 0.008 mm (.6189 ± .0003 in)

(13) Distance between the bearings for the governor control shaft . . . 60.58 ± 0.13 mm (2.385 ± .005 in)

(14) Distance from the face of the housing to the end of the bearing for the governor control shaft . . . 43.38 ± 0.15 mm (1.708 ± .006 in)
Shutoff Shaft Bearings

(15) Bore in the shutoff shaft bearing (new) . . . 12.713 ± 0.013 mm (.5005 ± .0005 in)

Diameter of the shutoff shaft (new) . . . 12.637 ± 0.013 mm (.4975 ± .0005 in)

(16) Torque for insulator . . . 4.5 ± 0.6 N·m (40 ± 5 lb in)

(17) Needle bearing.

(18) Distance from center of bolt hole to outside end of needle bearing (17) . . . 92.86 ± 0.25 mm (3.656 ± .010 in)

(19) Distance from end of needle bearing (17) to inside of sleeve bearing . . . 98.68 ± 0.25 mm (3.885 ± .010 in)

Install seals as shown.

Maximum end play for shaft . . . 1.02 mm (.040 in)

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Governor And Fuel Pump Drive (Automatic Timing Advance Unit)

(1) Weight (two).

(2) 3408C Outer Spring:

2W3985:

Length under test force . . . 57.2 mm (2.25 in)

Test force . . . 58.3 ± 2.9 N (13.10 ± .65 lb)

Free length after test . . . 68.2 mm (2.69 in)

Outside diameter . . . 25.3 mm (1.00 in)

Color Code (stripes) . . . one purple

(2) 3412C Outer Spring:

6N3191

Length under test force . . . 49.3 mm (1.94 in)

Test force . . . 100.6 ± 4.9 N (22.60 ± 1.10 lb)

Free length after test . . . 68.1 ± 0.8 mm (2.68 ± .03 in)

Outside diameter . . . 25.4 mm (1.00 in)

Color Code (stripes) . . . one red, one yellow

(3) 3408C Middle Spring:

2W3984:

Length under test force . . . 57.2 mm (2.25 in)

Test force . . . 19.4 ± 1.0 N (4.36 ± .22 lb)

Free length after test . . . 62.3 mm (2.45 in)

Outside diameter . . . 18.3 mm (.72 in)

Color Code (stripes) . . . one pink

(3) 3412C Middle Spring:

6N3189

Length under test force . . . 49.3 mm (1.94 in)

Test force . . . 72.5 ± 3.6 N (16.30 ± .80 lb)

Free length after test . . . 68.1 ± 0.8 mm (2.68 ± .03 in)

Outside diameter . . . 18.3 mm (.72 in)

Color Code (stripes) . . . one blue, one brown

(4) 3408C Inner Spring:

2W3983:

Length under test force . . . 43.03 mm (1.694 in)

Test force . . . 4.1 ± .2 N (.93 ± .05 lb)

Free length after test . . . 44.09 mm (1.736 in)

Outside diameter . . . 13.59 mm (.535 in)

Color Code (stripes) . . . one gray

(4) 3412C Inner Spring:

6N3190

Length under test force . . . 35.8 mm (1.41 in)

Test force . . . 10.0 ± 1.0 N (2.25 ± .23 lb)

Free length after test . . . 38.4 ± 0.8 mm (1.51 ± .03 in)

Outside diameter . . . 13.7 mm (.54 in)

Color Code (stripes) . . . one green, one white

(5) Torque for the four bolts . . . 136 ± 7 N·m (100 ± 5 lb ft)

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Fuel Transfer Pump Drive

(1) Bore in bearing (new) . . . 11.961 ± 0.033 mm (.4709 ± .0013 in)

Diameter of shaft (new) . . . 11.908 ± 0.005 mm (.4688 ± .0002 in)

(2) Temperature of the gear for installation on the shaft . . . 232°C (450°F)

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Fuel Transfer Pump

(1) Diameter of the shaft . . . 12.540 ± 0.003 mm (.4937 ± .0001 in)

Maximum temperature of the gear for installation on the shaft . . . 316°C (600°F)

NOTE: For position of gear on shaft, see (5).

Bore in the bearings (both) . . . 12.581 ± 0.013 mm (.4953 ± .0005 in)

Maximum permissible clearance between bearings and shaft (worn) . . . 0.08 mm (.003 in)

NOTE: The shaft must rotate freely when the cover bolts are tight.

(2) Clearance between the gears and the cover (new) . . . 0.020 to 0.051 mm (.0008 to .0020 in)
(3) Diameter of the shaft . . . 12.482 ± 0.008 mm (.4914 ± .0003 in)

Bore in the gear . . . 12.512 ± 0.008 mm (.4926 ± .0003 in)

Clearance between shaft and gear (new) . . . 0.015 to 0.046 mm (.0006 to .0018 in)

(4) Depth of the bore in the body (new) . . . 12.687 ± 0.008 mm (.4995 ± .0003 in)

(5) Distance from the gear to the shoulder of the shaft . . . 49.71 mm (1.957 in)

(6) Torque for plug of bypass valve . . . 37 ± 4 N·m (27 ± 3 lb ft)

Pressure of fuel to open the valve . . . 230 kPa (33 psi)

(7) 6N1069 Spring for bypass valve:

Length under test force . . . 33.96 mm (1.337 in)

Test force . . . 26.0 ± 1.0 N (5.84 ± .23 lb)

Free length after test . . . 53.52 mm (2.107 in)

Outside diameter . . . 10.31 mm (.406 in)

(8) Torque for nut . . . 30 ± 7 N·m (22 ± 5 lb ft)

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Fuel Ratio Control

(1) 6N0515 Spring:

Length under test force . . . 46.0 mm (1.81 in)

Test force . . . 30.0 ± 2.0 N (6.74 ± .45 lb)

Free length after test . . . 74.9 mm (2.95 in)

Outside diameter . . . 20.6 mm (.81 in)

Color Code (stripes) . . . one yellow

(2) 7N0209 Spring:

Length under test force . . . 32.3 mm (1.27 in)

Test force . . . 88.0 ± 8.0 N (19.78 ± 1.80 lb)

Free length after test . . . 37.8 mm (1.49 in)

Outside diameter . . . 45.4 mm (1.79 in)

Color Code (stripes) . . . two yellow

(3) 6N0513 Spring:

Length under test force . . . 14.0 mm (.55 in)

Test force . . . 120.0 ± 9.0 N (26.97 ± 2.02 lb)

Free length after test . . . 31.0 mm (1.22 in)

Outside diameter . . . 32.5 mm (1.28 in)

Color Code (stripes) . . . one yellow

(4) 9N1754 Spring:

Length under test force . . . 12.0 mm (.47 in)

Test force . . . 6.2 ± 0.4 N (1.40 ± .10 lb)

Free length after test . . . 17.5 mm (.69 in)

Outside diameter . . . 4.6 mm (.18 in)

Color Code (stripes) . . . none

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Governor Control

(1) Control in low idle position.

(2) Control in high idle position.

(3) Length of rod assembly between rod centers

60HZ Application . . . 182 ± 2 mm (7.17 ± .08 in)

50HZ Application . . . 173 ± 2 mm (6.81 ± .08 in)

(4) Tighten locknuts to a torque of . . . 8 ± 3 N·m (6 ± 2 lb ft)

(5) 7G8802 Gear Motor:

Rated voltage . . . 28 VDC

Voltage range . . . 18 to 32 VDC

No load speed at rated voltage . . . 1.00 ± .25 rpm

Shaft output at 28 VDC and 25°C (77°F):

Stall torque . . . 10.2 N·m (7.6 lb ft)

Stall current . . . 240 MA max.

Rotation is counterclockwise (as viewed from the output shaft end) when red lead is positive (+) and black lead is negative (-).

NOTE: Install motor with connection wires below the centerline of the motor as shown.
(A) Angle (A) with control in the high idle position (2) is:

60HZ Application . . . 44 degrees

50HZ Application . . . 24 degrees

(B) Angle (B) with control in the low idle position (1) is . . . 14 ± 2 degrees

(C) Angle (C) with control in the high idle position (2) is:

60HZ Application . . . 60 degrees

50HZ Application . . . 52 degrees

(D) Angle (D) with control in the low idle position (1) is:

60HZ Application . . . 5 degrees

50HZ Application . . . 20 degrees

(1) With the governor at low idle position, assemble handle from a vertical centerline to make angle (A) . . . 121/2 degrees

(2) 4W2542 Spring:

Length under test force . . . 53.3 mm (2.10 in)

Test force . . . 53.4 ± 4.3 N (12.00 ± .97 lb)

Free length after test . . . 98.0 mm (3.86 in)

Outside diameter . . . 15.24 mm (.600 in)

(3) Adjustment screw.

(4) Quadrant.

(5) 2H0210 Spring:

Length under test force . . . 26.19 mm (1.031 in)

Test force . . . 28.0 ± 1.4 N (6.30 ± .31 lb)

Free length after test . . . 119.86 mm (4.719 in)

Outside diameter . . . 19.05 mm (.750 in)

(6) Locknuts. Turn locknuts to position adjustment screw (3) and quadrant (4) until the handle can be moved to the high and low idle
positions.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Ether Starting Aid

Installation Diagram

(1) Ether cylinder assembly.

(2) Clamp assembly. Position clamp assembly 178 mm (7.0 in) vertically above ether valve assembly mounting holes.

(3) Ether valve assembly. With ether cylinder assembly (1) installed, the valve assembly provides 2.25 cc of ether through the steel tube to
atomizer (8) in the air inlet manifold system each time starting aid switch (5) is pressed for three seconds, then released.

Locate as close to the engine air inlet manifold as possible (do not mount on engine).

Do not mount in a location that subjects ether valve assembly (3) and ether cylinder assembly (1) to temperatures greater than 93.3°C (200°
F).

Install ether valve assembly (3) so ether cylinder assembly (1) can be installed in a vertical position as shown.

(4) Temperature switch. The temperature switch will not allow starting fluid to reach the atomizer if the engine temperature is above 38°C
(100°F).

Remove the 3/8 inch pipe plug from the cylinder head and install temperature switch in location shown in the engine series detail.

(5) Starting aid switch. Install switch close to operator's starting station. Switch requires clearance hole for 5/8inch diameter thread, and 38
mm (1.50 in) depth behind control panel or mounting bracket.

(6) Ether valve connector.

(7) Steel tube. Assemble 3.18 mm (.125 in) OD steel tubing between valve assembly and atomizer assembly. Use the flexible coupling tube
assembly as a flexible connection between the two lines. The use of any additional length of tubing is not recommended. No electric wires
are to be clamped to the ether line.

(8) Atomizer assembly. Remove 1/4 inch pipe plug from air inlet system and install atomizer assembly. Before atomizer assembly is
tightened, turn identification mark to direction shown in engine series detail for correct alignment of ether spray.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Primary Fuel Filter

(1) Torque for nut . . . 25 ± 4 N·m (18 ± 3 lb ft)

(2) 7S9323 Spring

Length under test force . . . 27.9 mm (1.10 in)

Test force . . . 135.0 ± 10.0 N (30.34 ± 2.25 lb)

Free length after test . . . 42.7 mm (1.68 in)

Outside diameter . . . 17.3 mm (.68 in)

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Fuel Filter Base

3408C

(1) Stud (two) used when filter base is installed high on the inlet manifold. Install stud so end of stud extends above surface of manifold
boss to a dimension of . . . 24.3 ± 1.5 mm (.96 ± .06 in)

(2) Put 4C9507 Retaining Compound on the tapered end of stud to a distance of . . . 7.6 mm (.30 in)

(3) Sealing surface of stud.

NOTE: Do not damage this surface.

(4) Distance from sealing surface of base to end of stud . . . 24.6 ± 1.3 mm (.97 ± .05 in)

(5) Torque for stud . . . 70 ± 15 N·m (50 ± 11 lb ft)

3412C
(1) Put 4C9507 Retaining Compound on the tapered end of stud to a distance of . . . 7.6 ± 1.5 mm (.30 ± .06 in)

(2) Distance from sealing surface of base to end of stud . . . 24.6 ± 1.3 mm (.97 ± .05 in)

(3) Sealing surface of stud.

NOTE: Do not damage this surface.

(4) Torque for stud . . . 70 ± 15 N·m (50 ± 11 lb ft)

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Valve Mechanism Covers

Typical Illustration (3408C Shown)

(1) Coat joints with 3S6252 Sealant on both ends.

(2) Tighten the bolts for the base to . . . 14 ± 4 N·m (10 ± 3 lb ft)

(3) Tighten the bolts for the cover to . . . 14 ± 4 N·m (10 ± 3 lb ft)

(4) Cap assembly.

(5) Adapter and seal. Lubricate joint surface and seal with clean engine oil. Freeze adapter to at least -18°C (-1°F).

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Valve Rocker Arms, Lifters And Bridges

Sequence For Rocker Arm Bolts (3408C)

Sequence For Rocker Arm Bolts (3412C)

(1) Bore in rocker arm for shaft (new) . . . 24.803 ± 0.013 mm (.9765 ± .0005 in)

Diameter of shaft (new) . . . 24.750 ± 0.013 mm (.9744 ± .0005 in)

(2) Put 6V4876 Molykote Paste Lubricant on the threads of all bolts, and between the washer and underside of bolt head that hold rocker
arm shaft and tighten the bolts in the following step sequence.

1. Tighten bolts in number sequence to . . . 270 ± 25 N·m (200 ± 20 lb ft)

2. Tighten bolts in number sequence to . . . 450 ± 20 N·m (330 ± 15 lb ft)

3. Tighten bolts in number sequence again to . . . 450 ± 20 N·m (330 ± 15 lb ft)

(3) Torque for locknut for valve adjustment screw . . . 30 ± 4 N·m (22 ± 3 lb ft)

(4) Torque for locknut for bridge adjustment screw . . . 30 ± 4 N·m (22 ± 3 lb ft)

(5) Valve lash:

Inlet valves . . . 0.38 mm (.015 in)

Exhaust valves . . . 0.76 mm (.030 in)

(6) Height to top of dowel . . . 53.3 ± 0.5 mm (2.10 ± .02 in)

(7) Diameter of dowel (new) . . . 11.008 ± 0.003 mm (.4334 ± .0001 in)

Bore in bridge for dowel (new) . . . 11.13 ± 0.05 mm (.438 ± .002 in)

Bore in head for dowel . . . 10.968 ± 0.020 mm (.4318 ± .0008 in)

(8) Diameter of valve lifter (new) . . . 27.896 ± 0.013 mm (1.0983 ± .0005 in)

Bore in block for valve lifter (new) . . . 27.9527 ± 0.0190 mm (1.10050 ± .00075 in)

NOTE: See Guideline For Reusable Parts; Salvage Of Lifter Bores in 3400 Series Engines, SEBF8069 for the procedure, tooling and
specifications needed to install 4W4588 Sleeves for salvage of the lifter bores in the cylinder block.
(9) Lifter guide springs must not be used again. Always install new lifter guide springs.

(10) 2N7229 Spring:

Length under test force . . . 74.2 mm (2.92 in)

Test force . . . 49.0 ± 4.0 N (11.01 ± .90 lb)

Free length after test . . . 114.3 mm (4.50 in)

Outside diameter . . . 29.7 mm (1.17 in)

(11) Dowel length above top surface of rocker shaft support to be (both ends) . . . 12.7 ± 1.0 mm (.50 ± .04 in)

(12) Clearance for rocker arms (both ends) . . . 0.30 to 1.40 mm (.012 to .055 in)

(13) Use 2N7228 Washer as needed to get clearance (12).

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Valves, Valve Springs And Valve Seat Inserts

NOTE: Guidelines For Reusable Parts; Valves And Valve Springs, SEBF8002 and SEBF8034, have the procedure and specifications
necessary for checking used valves and valve springs.

(1) 4N5906 Spring for valves (new):

Length under test force . . . 54.99 mm (2.165 in)

Test force . . . 344.0 ± 34.0 N (77.30 ± 7.64 lb)

Free length after test . . . 62.74 mm (2.470 in)

Outside diameter . . . 31.75 mm (1.250 in)

(2) Height to top of valve guide . . . 32.3 ± 0.8 mm (1.27 ± .03 in)
(3) Diameter of valve stem (new) . . . 9.441 ± 0.010 mm (.3717 ± .0004 in)

Use again minimum diameter of inlet and exhaust valve stem . . . 9.408 mm (.3704 in)

Bore in valve guide with guide installed in the head (new) . . . 9.487 ± 0.025 mm (.3735 ± .0010 in)

(4) Diameter of valve head:

Exhaust valve . . . 41.81 ± 0.13 mm (1.646 ± .005 in)

Inlet valve . . . 44.98 ± 0.13 mm (1.771 ± .005 in)

(5) Angle of inlet valve face . . . 29 1/4 ± 1/4 degree

Angle of exhaust valve face . . . 44 1/4 ± 1/4 degree

(6) Depth of bore in head for valve seat insert (new) . . . 13.01 ± 0.35 mm (.512 ± .014 in)

(7) Diameter of valve seat insert for exhaust valve . . . 42.850 ± 0.013 mm (1.6870 ± .0005 in)

Bore in head for valve seat insert for exhaust valve . . . 42.774 ± 0.025 mm (1.6840 ± .0010 in)

(7) Diameter of valve seat insert for inlet valve . . . 46.025 ± 0.013 mm (1.8120 ± .0005 in)

Bore in head for valve seat insert for inlet valve . . . 45.949 ± 0.025 mm (1.8090 ± .0010 in)

(8) Angle of face of inlet valve seat insert . . . 30 1/4 ± 1/2 degree

Angle of face of exhaust valve seat insert . . . 44 3/4 ± 1/2 degree

(9) Dimension from end of closed valve to machined face of head.

Maximum permissible dimension (new):

Below (recessed from) machined face . . . 1.22 mm (.048 in)

Above (extended from) machined face . . . 0.04 mm (.002 in)

Maximum permissible dimension (reconditioned):

Below (recessed from) machined face . . . 1.70 mm (.067 in)

Above (extended from) machined face . . . 0.04 mm (.002 in)

(10) Outside diameter of the face of the valve seat insert:

Exhaust seat . . . 40.41 ± 0.13 mm (1.591 ± .005 in)

Inlet seat . . . 44.04 ± 0.13 mm (1.734 ± .005 in)

(11) "Use again" thickness of valve lip:

Exhaust valve . . . 2.03 mm (.080 in)

Inlet valve . . . 2.51 mm (.099 in)

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Camshaft

(1) Camshaft gear. If a new gear is required, replace the camshaft assembly.

(2) Diameter of the surfaces (journals) for the camshaft bearings (new) . . . 69.850 ± 0.013 mm (2.7500 ± .0005 in)

Bore in front and rear bearings for the camshaft (new) . . . 69.969 ± 0.048 mm (2.7547 ± .0019 in)

Bore in the inner bearings for the camshaft (new) . . . 69.982 ± 0.061 mm (2.7552 ± .0024 in)

(3) Thickness of thrust plate (new) . . . 4.65 ± 0.03 mm (.183 ± .001 in)

End play of the camshaft . . . 0.10 to 0.25 mm (.004 to .010 in)

(4) Camshaft.
(5) Height of camshaft lobes.

To find lobe height, use the following procedure:

A. Measure camshaft lobe height (5).

B. Measure base circle (7).

C. Subtract base circle (Step B) from lobe height (Step A). The difference is actual lobe lift.

D. Specified camshaft lobe lift (6) is:

a. Exhaust lobe . . . 8.783 mm (.3458 in)

b. Inlet lobe . . . 8.100 min (.3189 in)

Maximum permissible difference between actual lobe lift (Step C) and specified lobe lift (Step D) is 0.13 mm (.005 in)

Projection of dowel at tapered end (opposite camshaft gear) of camshaft (3408C only) . . . 8.76 ± 0.25 mm (.345 ± .010 in)

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Front Gear Group (Timing)

3408C

(1) Fuel injection pump drive gear and timing advance unit.

(2) Camshaft gear.

NOTE: Make alignment of "V" marks as shown.

(3) Water pump drive gear.

(4) Gear for attachment drive groups.

(5) Idler gear (balancer gear) assembly.

NOTE: Make alignment of "V" marks as shown.

(6) Tighten five bolts to a torque of . . . 55 ± 7 N·m (40 ± 5 lb ft)

(7) Diameter of the shaft (new) . . . 63.500 ± 0.013 mm (2.5000 ± .0005 in)

Bore in bearing (after assembly) . . . 63.602 ± 0.038 mm (2.504 ± .0015 in)

(8) End clearance (new) . . . .31 ± .17 mm (.012 ± .007 in)

(9) Plate. The lubrication groove must be against the gear.

(10) Crankshaft gear.

NOTE: Make alignment of "V" mark as shown.

(11) Engine oil pump drive gear.

(12) Tighten the bolt that holds the drive gear to a torque . . . 55 ± 7 N·m (40 ± 5 lb ft)

3412C
(1) Fuel injection pump drive gear and timing advance unit.

(2) Camshaft gear.

NOTE: Make alignment of "V" marks as shown.

(3) Water pump drive gear.

(4) Gear for attachment drive groups.

(5) Idler gear assembly.

NOTE: Make alignment of "V" marks as shown.

(6) Tighten five bolts to a torque of . . . 55 ± 7 N·m (40 ± 5 lb ft)

(7) Diameter of the shaft (new) . . . 63.500 ± 0.013 mm (2.5000 ± .0005 in)

Bore in bearing (after assembly) . . . 63.602 ± 0.038 mm (2.504 ± .0015 in)

(8) End clearance (new) . . . .31 ± .17 mm (.012 ± .007 in)

(9) Plate. The lubrication groove must be against the gear.

(10) Crankshaft gear.

NOTE: Make alignment of "V" mark as shown.

(11) Distance that bearing is installed from the face of idler gear . . . 1.12 ± 0.25 mm (.044 ± .010 in)

(12) Diameter of the shaft (new) . . . 34.943 ± 0.013 mm (1.3757 ± .0005 in)

Bore in bearing (after assembly) . . . 35.034 ± 0.038 mm (1.3793 ± .0015 in)

(13) Engine oil pump idler gear. Tighten the bolt that holds idler gear to a torque of . . . 55 ± 7 N·m (40 ± 5 lb ft)

(14) Engine oil pump drive gear. Tighten the bolt that holds the drive gear to a torque . . . 55 ± 7 N·m (40 ± 5 lb ft)

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Front Housing And Covers

(1) Torque for stud on back of the cover . . . 27 ± 4 N·m (20 ± 3 lb ft)

(2) Put 9S3263 Thread Lock on the threads of stud.

Dimension stud must extend from surface of timing gear housing . . . 73.2 mm (2.88 in)

(3) Torque for three studs . . . 27 ± 4 N·m (20 ± 3 lb ft)

(4) Dimension stud must extend from surface of timing gear housing . . . 28.5 ± 1.5 mm (1.12 ± .06 in)

NOTE: Cut the gasket between the timing gear cover and the block even with the bottom of the timing gear cover after assembly.
Copyright 1991, 2004 Caterpillar Inc.
All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Cylinder Heads

3408C

(1) Large bolts (3/4 in). Put 6V4876 Molykote Paste Lubricant on the threads of all bolts, and between the washer and underside of bolt
head and tighten the bolts in the step sequence that follows:

1. Tighten bolts from 1 to 10 in number sequence to . . . 270 ± 25 N·m (200 ± 20 lb ft)

2. Tighten bolts from 1 to 10 in number sequence to . . . 470 ± 20 N·m (345 ± 15 lb ft)

3. Tighten bolts from 1 to 10 in number sequence again to . . . 470 ± 20 N·m (345 ± 15 lb ft)

4. Install the rocker arms for the engine valves and the remaining (3/4 in) bolts. Put 6V4876 Molykote Paste Lubricant on the threads of all
bolts, and between the washer and underside of bolt head and tighten the bolts in the step sequence that follows.

5. Tighten bolts from 11 to 18 in number sequence to . . . 270 ± 25 N·m (200 ± 20 lb ft)

6. Tighten bolts from 11 to 18 in number sequence to . . . 450 ± 20 N·m (330 ± 15 lb ft)

7. Tighten bolts from 11 to 18 in number sequence again to . . . 450 ± 20 N·m (330 ± 15 lb ft)
Typical Example

(2) Small bolts (3/8 in). Put clean engine oil on the bolt threads and use the following tightening procedure.

Four bolts marked X:

a. Tighten bolts marked X finger tight.

b. Tighten timing gear housing to bracket bolts to standard torque.

c. Tighten bolts marked X to . . . 45 ± 7 N·m (33 ± 5 lb ft)

Bolts marked Y and Z:

a. Tighten bolts marked Z finger tight.

b. Tighten bolts marked Y to standard torque.

c. Tighten bolts marked Z to . . . 45 ± 7 N·m (33 ± 5 lb ft)

Tighten the remaining 3/8 bolts (2) to . . . 45 ± 7 N·m (33 ± 5 lb ft)

(3) Torque for eight exhaust manifold studs in each cylinder head . . . 35 ± 5 N·m (26 ± 4 lb ft)
(4) Height of cylinder head (new) . . . 112.78 ± 0.25 mm (4.440 ± .010 in)

Minimum permissible thickness of cylinder head . . . 111.51 mm (4.390 in)

3412C

(1) Large bolts (3/4 in). Put 6V4876 Molykote Paste Lubricant on the threads of all bolts, and between the washer and underside of bolt
head and tighten the bolts in the step sequence that follows:

1. Tighten bolts from 1 to 14 in number sequence to . . . 270 ± 25 N·m (200 ± 20 lb ft)

2. Tighten bolts from 1 to 14 in number sequence to . . . 470 ± 20 N·m (345 ± 15 lb ft)

3. Tighten bolts from 1 to 14 in number sequence again to . . . 470 ± 20 N·m (345 ± 15 lb ft)

4. Install the rocker arms for the engine valves and the remaining (3/4 in) bolts. Put 6V4876 Molykote Paste Lubricant on the threads of all
bolts, and between the washer and underside of bolt head and tighten the bolts in the step sequence that follows.

5. Tighten bolts from 15 to 26 in number sequence to . . . 270 ± 25 N·m (200 ± 20 lb ft)

6. Tighten bolts from 15 to 26 in number sequence to . . . 450 ± 20 N·m (330 ± 15 lb ft)

7. Tighten bolts from 15 to 26 in number sequence again to . . . 450 ± 20 N·m (330 ± 15 lb ft)

Typical Example

(2) Small bolts (3/8 in). Put clean engine oil on the bolt threads and use the following tightening procedure.

Four bolts marked X:

a. Tighten bolts marked X finger tight.

b. Tighten timing gear housing to bracket bolts to standard torque.

c. Tighten bolts marked X to . . . 45 ± 7 N·m (33 ± 5 lb ft)

Bolts marked Y and Z:

a. Tighten bolts marked Z finger tight.

b. Tighten bolts marked Y to standard torque.

c. Tighten bolts marked Z to . . . 45 ± 7 N·m (33 ± 5 lb ft)

Tighten the remaining 3/8 bolts (2) to . . . 45 ± 7 N·m (33 ± 5 lb ft)

(3) Torque for eight exhaust manifold studs in each cylinder head . . . 35 ± 5 N·m (26 ± 4 lb ft)

(4) Height of cylinder head (new) . . . 112.78 ± 0.25 mm (4.440 ± .010 in)

Minimum permissible thickness of cylinder head . . . 111.51 mm (4.390 in)

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Air Cleaner Adapter

(1) Tighten three bolts to a torque of . . . 24 ± 7 N·m (18 ± 5 lb ft)

(1) Tighten 24 bolts to a torque of . . . 12 ± 4 N·m (9 ± 3 lb ft)

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Air Cleaner Group

Typical Illustration

1N4460, 1W0744, 2W6183

(1) Tighten ten locknuts to a torque of . . . 30 ± 7 N·m (22 ± 5 lb ft)

113-3152, 113-3154

(1) Tighten ten locknuts to a torque of . . . 30 ± 7 N·m (22 ± 5 lb ft)

Clamp Tightening Sequence

4N2905, 2W3207

Tighten clamps in the sequence shown.

8N3110, 8N3111, 8N3371, 8N3372, 7W1409

(1) Tighten three bolts to a torque of . . . 24 ± 7 N·m (18 ± 5 lb ft)

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Exhaust Manifolds

3412C Shown

Air Cooled

NOTE: Apply 2P2333 Manifold Sealer to the OD of male ends of manifolds and apply engine oil to the female ends of manifolds before
assembly.

NOTE: Put 5P3931 Anti-Seize Compound on the threads of all studs at assembly.

(1) Tighten the locknuts for the manifold to . . . 38 ± 5 N·m (28 ± 4 lb ft)

NOTE: Tightening sequence is for the 3412C only.

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Inlet Air And Exhaust Lines

3408C

NOTE: Put 5P3931 Anti-Seize Compound on the threads of all plugs, studs, bolts and nuts for the exhaust manifolds, couplings, elbows,
and turbocharger support where they become very hot.

Typical Illustration

(1) Tighten all clamps to a torque of . . . 7.5 ± 1.0 N·m (66 ± 9 lb in)

(2) Torque for four studs . . . 35 ± 5 N·m (26 ± 4 lb ft)

(3) Torque for four studs . . . 35 ± 5 N·m (26 ± 4 lb ft)

(4) Torque for bolt that holds exhaust manifold support to engine . . . 55 ± 7 N·m (40 ± 5 lb ft)

3412C

NOTE: Put 5P3931 Anti-Seize Compound on the threads of all plugs, studs, bolts and nuts for the exhaust manifolds, couplings, elbows,
and turbocharger support where they become very hot.
(1) Tighten all clamps to a torque of . . . 7.5 ± 1.0 N·m (66 ± 9 lb in)

(2) Torque for bolt . . . 55 ± 7 N·m (40 ± 5 lb ft)

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Exhaust Elbow Group

(1) Tighten all clamps to a torque of . . . 14 ± 3 N·m (10 ± 2 lb ft)

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Exhaust Elbow Group

(1) Tighten all clamps to a torque of . . . 14 ± 3 N·m (10 ± 2 lb ft)

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Muffler Mounting Group

Typical Illustration

1W3166, 1W3167, 1W3168, 2W6191, 4W2990

(1) Tighten all clamps to a torque of . . . 25 ± 7 N·m (18 ± 5 lb ft)

(2) Apply 5P3931 Anti-Seize Compound to the bolt.

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Turbocharger

TW81

(1) Turbocharger impeller installation:

a. Put impeller on shaft.

b. Put a small amount of clean engine oil on the threads and impeller face that will be under the nut.

c. Tighten the nut to . . . 15.5 ± 1.5 N·m (11 ± 1 lb ft)

Do not bend or add stress to the shaft when the nut is loosened or tightened.
d. Remove the nut and apply 4C9500 Quick Cure Primer on the threads of the shaft and nut.

e. Put 4C9507 Retaining Compound on the threads of the shaft and nut.

f. Install and tighten nut to . . . 4 N·m (35 lb in)

g. Tighten nut an additional . . . 120 degrees

(2) Torque for bolts . . . 11 ± 1 N·m (97 ± 9 lb in)

(3) Torque for the clamp bolts . . . 14.0 ± 1.5 N·m (10 ± 1 lb ft)

Lightly hit all around clamp with a soft hammer and again tighten to . . . 14.0 ± 1.5 N·m (10 ± 1 lb ft)

(4) Bore in the bearings . . . 15.921 to 15.931 mm (.6268 to .6272 in)

Diameter for the surfaces (journals) on the shaft for the bearings . . . 15.875 to 15.885 mm (.6250 to .6254 in)

(5) Bore in the housing . . . 24.961 to 24.973 mm (.9827 to .9832 in)

Outside diameter of the bearing . . . 24.846 to 24.859 mm (.9782 to .9787 in)

(6) Clearance between the ends of the oil seal ring (when installed in its bore) . . . 0.20 to 0.38 mm (.008 to .015 in)

(7) End play for the shaft . . . 0.08 to 0.13 mm (.003 to .005 in)

(8) Torque for bolts and nuts that hold the turbocharger to the exhaust manifold (put 5P3931 Anti-Seize Compound on the threads) . . . 55 ±
5 N·m (40 ± 4 lb ft)

TW91
(1) Turbocharger impeller installation at room temperature:

a. Put impeller on shaft.

b. Put a small amount of 4C5593 Anti-Seize Compound on the threads and impeller face that will be under the nut.

c. Tighten the nut to . . . 31 N·m (23 lb ft)

NOTE: Do not bend or add stress to the shaft when the nut is loosened or tightened.

d. Loosen the nut on the shaft.

e. Tighten the nut to . . . 5 N·m (50 lb in)

f. Tighten the nut more . . . 120 degrees

g. Remove the nut from the shaft.

h. Use 6V1541 Quick Cure Primer on the threads of the shaft and nut.

j. Put 9S3265 Retaining Compound on the threads of the shaft and nut.

k. Tighten the nut to . . . 5 N·m (50 lb in)

l. Tighten the nut an additional . . . 120 degrees

(2) Torque for the clamp bolts . . . 14.0 ± 1.5 N·m (10 ± 1 lb ft)

Lightly hit all around clamp with a soft faced hammer and again tighten to . . . 14.0 ± 1.5 N·m (10 ± 1 lb ft)

(3) Bore in the bearings . . . 21.585 to 21.595 mm (.8498 to .8502 in)

Diameter for the surfaces (journals) on the shaft for the bearings . . . 21.539 to 21.595 mm (.8480 to .8484 in)

(4) Bore in the housing . . . 30.594 to 30.607 mm (1.2045 to 1.2050 in)

Outside diameter of the bearings . . . 30.467 to 30.480 mm (1.1995 to 1.2000 in)

(5) Clearance between the ends of the oil seal ring . . . 0.20 to 0.38 mm (.008 to .015 in)

(6) End play for the shaft . . . 0.165 ± 0.063 mm (.0065 ± .0025 in)

(7) Torque for the bolts that hold the backplate . . . 40 ± 2 N·m (30 ± 1 lb ft)

(8) Torque for the bolts that hold the turbine housing to the cartridge housing (put 5P3931 Anti-Seize on the threads) . . . 40 ± 2 N·m (30 ±
1 lb ft)

Torque for bolts and nuts that hold the turbocharger to the exhaust manifold (put 5P3931 Anti-Seize Compound on the threads) . . . 55 ± 5
N·m (40 ± 4 lb ft)

4MF
(1) Turbocharger impeller installation:

a. Put impeller on shaft.

b. Put a small amount of clean engine oil on the threads and impeller face that will be under the nut.

c. Tighten the nut to . . . 59.8 ± 2.7 N·m (44 ± 2 lb ft)

Do not bend or add stress to the shaft when the nut is loosened or tightened.

d. Remove the nut and apply 4C9500 Quick Cure Primer on the threads of the shaft and nut.

e. Put 4C9507 Retaining Compound on the threads of the shaft and nut.

f. Tighten the nut to . . . 59.8 ± 2.7 N·m (44 ± 2 lb ft)

(2) Torque for bolts . . . 11 ± 1 N·m (97 ± 9 lb in)

(3) Torque for the clamp bolts . . . 14 ± 1.5 N·m (10 ± 1 lb ft)

Lightly hit all around clamp with a soft hammer and again tighten to . . . 14.0 ± 1.5 N·m (10 ± 1 lb ft)

(4) Bore in the bearings . . . 15.921 to 15.931 mm (.6268 to .6272 in)

Diameter for the surfaces (journals) on the shaft for the bearings . . . 15.875 to 15.885 mm (.6250 to .6254 in)

(5) Bore in the housing . . . 24.961 to 24.973 mm (.9827 to .9832 in)

Outside diameter of the bearing . . . 24.846 to 24.859 mm (.9782 to .9787 in)

(6) Clearance between the ends of the oil seal ring (when installed in its bore) . . . 0.20 to 0.38 mm (.008 to .015 in)

(7) End play for the shaft . . . 0.08 to 0.13 mm (.003 to .005 in)

(8) Torque for bolts and nuts that hold the turbocharger to the exhaust manifold (put 5P3931 Anti-Seize Compound on the threads) . . . 55 ±
5 N·m (40 ± 4 lb ft)

TV81, F555

(1) Torque for bolts . . . 3.65 ± 0.25 N·m (32 ± 2 lb in)

(2) Bore in the bearings . . . 15.921 to 15.931 mm (.6268 to .6272 in)

Diameter for the surfaces (journals) on the shaft for the bearings . . . 15.875 to 15.885 mm (.6250 to .6254 in)

(3) Bore in the housing . . . 24.961 to 24.973 mm (.9827 to .9832 in)

Outside diameter of the bearing . . . 24.846 to 24.859 mm (.9782 to .9787 in)

(4) Clearance between the ends of the oil seal ring (when installed in its bore) . . . 0.20 to 0.38 mm (.008 to .015 in)

(5) Turbocharger impeller installation:

a. Put impeller on shaft.

b. Put a small amount of clean engine oil on the threads and impeller face that will be under the nut.

c. Tighten the nut to . . . 15.5 ± 1.5 N·m (11 ± 1 lb ft)

Do not bend or add stress to the shaft when the nut is loosened or tightened.

d. Remove the nut and apply 4C9500 Quick Cure Primer on the threads of the shaft and nut.

e. Put 4C9507 Retaining Compound on the threads of the shaft and nut.

f. Install and tighten nut to . . . 4 N·m (35 lb in)

g. Tighten nut an additional . . . 120 degrees

(6) End play for the shaft . . . 0.08 to 0.13 mm (.003 to .005 in)

(7) Torque for bolts . . . 11 ± 1 N·m (97 ± 9 lb in)

Torque for the clamp bolts . . . 14.0 ± 1.5 N·m (10 ± 1 lb ft)

Lightly hit all around clamp with a soft hammer and again tighten to . . . 14.0 ± 1.5 N·m (10 ± 1 lb ft)

Torque for bolts and nuts that hold the turbocharger to the exhaust manifold (put 5P3931 Anti-Seize Compound on the threads) . . . 55 ± 5
N·m (40 ± 4 lb ft)

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Engine Oil Filters And Bypass Valves

Typical Illustration

(1) Bypass valve for the oil cooler.

(2) Bypass valve for the oil filters.

(3) Torque for the center studs under the filter base [put 9S3263 Thread Lock on last 7.6 mm (.30 in) of thread at base end of studs] . . . 80
± 14 N·m (60 ± 10 lb ft)

NOTE: Put clean engine oil on the filter seals. Put the filters in position on stud (3) and tighten until the seals make contact with the base.
Turn the filters 270 degrees (3/4 of one turn) more.

(4) 4N8150 Spring for either bypass valve (1) OR (2):

Length under test force . . . 55.25 mm (2.175 in)

Test force . . . 75.0 ± 5.0 N (16.85 ± 1.12 lb)

Free length after test . . . 93.7 mm (3.69 in)

Outside diameter . . . 20.6 mm (.81 in)

Pressure difference required to open bypass valve . . . 255 ± 21 kPa (37 ± 3 psi)
(1) 4N8150 Spring for bypass valve

Length under test force . . . 55.25 mm (2.175 in)

Test force . . . 75.0 ± 5.0 N (16.85 ± 1.12 lb)

Free length after test . . . 93.7 mm (3.69 in)

Outside diameter . . . 20.6 mm (.81 in)

Pressure difference to open either bypass valve . . . 255 ± 20 kPa (37 ± 3 psi)

(2) Tighten studs to a torque of . . . 27 ± 4 N·m (20 ± 3 lb ft)

(3) Torque for the two center studs under the filter base [put 9S3263 Thread Lock on last 7.6 mm (.30 in) of thread at base end of studs] . . .
80 ± 14 N·m (60 ± 10 lb ft)

NOTE: Put clean engine oil on the filter seals. Put the filters in position on stud (3) and tighten until the seals make contact with the base.
Turn the filters 270 degrees (3/4 of one turn) more.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Oil Breather Cap

(1) Torque for clamp . . . 4.5 ± 0.5 N·m (39 ± 4 lb in)

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Engine Oil Pump

NOTE: Make reference to Front Gear Group (Timing) to find oil pump drive gear.

(1) Diameter of drive shaft and idler shaft (new) . . . 22.217 ± 0.005 mm (.8747 ± .0002 in)

Bore in bearings for drive shaft and idler shaft (new) . . . 22.258 ± 0.008 mm (.8763 ± .0003 in)

(2) Length of gears (new) . . . 79.375 ± 0.025 mm (3.1250 ± .0010 in)

Depth of bores for gears (new) . . . 79.502 ± 0.020 mm (3.1300 ± .0008 in)

(3) 2S2760 Spring (oil pressure relief valve):

Length under test force . . . 117.9 mm (4.64 in)

Test force . . . 490.0 ± 27.0 N (110.11 ± 6.07 lb)

Free length after test . . . 152.9 mm (6.02 in)

Outside diameter . . . 27.00 mm (1.063 in)

(4) Distance from the end of the idler shaft to gear face . . . 36.50 ± 0.25 mm (1.437 ± .010 in)
Maximum temperature of gear at installation . . . 316°C (600°F)

(5) Distance from the end of the drive shaft to gear face . . . 53.00 ± 0.25 mm (2.087 ± .010 in)

Maximum temperature of gear at installation . . . 316°C (600°F)

Pump Body

(6) Pump body bearing joints.

(7) Position of pump body bearing junction from the vertical centerline through bearing bores . . . 30 ± 15 degrees

(8) Install bearings in bottom of gear bores to a depth of . . . 0.30 mm (.002 in)

Before operation, the pump must be lubricated with clean engine oil and the pump must
turn freely by hand or damage to parts can be the result.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Oil Pan Adapter

4P0519 Drain Assembly

(1) Lubricate with oil and tighten to a torque of . . . 70 ± 13 N·m (50 ± 10 lb ft)

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Oil Pan

Typical Illustration (3408C shown)

(1) Torque for three one inch pipe plugs . . . 80 ± 11 N·m (60 ± 8 lb ft)

High Capacity Oil Pan

(1) Tighten bolts to a torque of . . . 55 ± 10 N·m (40 ± 7 lb ft)

(2) Tighten plug to a torque of . . . 70 ± 15 N·m (50 ± 11 lb ft)

(3) Tighten three plugs to a torque of . . . 82 ± 10 N·m (60 ± 7 lb ft)

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Belt Tension Chart

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Water Temperature Regulators

Temperature when completely open . . . 92°C (197°F)

Minimum stroke at full open temperature . . . 10.4 mm (.41 in)

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Coolant Conditioner Base

(1) Put 9S3263 Thread Lock on the tapered end of the stud to a distance of . . . 10.0 ± 1.5 mm (.39 ± .06 in)

(2) Tighten the stud to a torque of . . . 70 ± 15 N·m (50 ± 11 lb ft)

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Auxiliary Water Pump (Raw Water)

(1) Remove plug to prime.

(2) Torque for bolt . . . 55 ± 7 N·m (40 ± 5 lb ft)

(1) Torque for nut . . . 60 ± 7 N·m (44 ± 5 lb ft)

(2) Torque for nut . . . 100 ± 14 N·m (75 ± 10 lb ft)

Copyright 1991, 2004 Caterpillar Inc.
All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Water Pump

(1) Torque for three long studs in cylinder block . . . 27 ± 4 N·m (20 ± 3 lb ft)

NOTE: Put 9S3263 Thread Lock on threads of short stud in front housing.

(2) Oil seal. Put clean engine oil on the seal lip. Assemble with the lip toward the bearings.

(3) Seal. Put a thin layer of clean engine oil in the bore for the seal.

(4) Ring and water seal.

(5) Seal assembly.

NOTE: For proper installation procedure of the seals, refer to the Disassembly & Assembly module.

(6) Shaft diameter at carbon seal assembly seat area must be . . . 19.10 ± 0.05 mm (.752 ± .002 in)

(7) Torque for the bolt that holds the impeller . . . 39 ± 3 N·m (29 ± 2 lb ft)

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Cylinder Block

(1) Torque for three studs to hold the water pump . . . 27 ± 4 N·m (20 ± 3 lb ft)

(2) Plug (two on front and two on rear).

(3) Length of dowels (four) out of the block face . . . 18.5 ± 0.5 mm (.73 ± .02 in)

(4) Thickness of the gasket between the cylinder block and top plates . . . 0.21 ± 0.03 mm (.008 ± .001 in)

(5) Thickness of the top plates . . . 8.585 ± 0.025 mm (.3380 ± .0010 in)

(6) Make reference to Cylinder Liner Projection in the Systems Operation, Testing & Adjusting, for the height of the liner.

(7) Bore in the block for the camshaft bearings (seven bores) . . . 76.835 ± 0.018 mm (3.0250 ± .0007 in)

(8) Torque for one plug on front and two on rear of the block . . . 80 ± 15 N·m (60 ± 11 lb ft)

Put 5P3413 Pipe Sealant on the threads of the plug.

(9) Bore in the block for the main bearings:

Standard, original size (new) . . . 129.891 ± 0.013 mm (5.1138 ± .0005 in)

0.64 mm (.025 in) larger than original size . . . 130.526 ± 0.013 mm (5.1388 ± .0005 in)

(10) Projection of dowels (four) out of the front and rear faces of the block . . . 19.0 ± 0.5 mm (.75 ± .02 in)

(11) Width of slot for bearing cap . . . 215.900 ± 0.013 mm (8.5000 ± .0005 in)
Width of bearing cap . . . 215.900 ± 0.013 mm (8.5000 ± .0005 in)

Press fit between sides of the main bearing cap and the cylinder block . . . 0.026 mm (.0010 in) tight to 0.026 mm (.0010 in) loose

(12) Torque for the bolts that hold the piston cooling tubes . . . 25 ± 7 N·m (18 ± 5 lb ft)

(13) Torque for the bolts that hold the caps for the main bearings:

Install the main bearing caps with the marks (arrow) toward the front of the engine. Each cap has a number on the bottom and must be
installed in the same position as the correct number on the left side of the block pan rail.

a. Tighten the bolts on left (tab) side to . . . 258 ± 14 N·m (190 ± 10 lb ft)

b. Tighten the bolts on right side to . . . 258 ± 14 N·m (190 ± 10 lb ft)

c. Put a mark on each bolt and cap.

d. Tighten the bolts on right side, from the mark . . . 120 ± 5 degrees

e. Tighten the bolts on left (tab) side, from the mark . . . 120 ± 5 degrees

(14) Dimension (new) from the centerline of crankshaft bearing bore to top of block (top deck) . . . 419.10 ± 0.15 mm (16.500 ± .006 in)

(15) Dimension (new) from centerline of crankshaft bearing bore to bottom of block (pan rails) . . . 165.10 ± 0.10 mm (6.500 ± .004 in)
Right Side Of Engine

(16) Plug. Two plugs (one located at front and the other located at rear of right cylinder bank).

(17) Plug.

NOTE: Put 9S3263 Thread Lock on the threads of all plugs installed without a seal.

NOTE: For cylinder block repair procedures, refer to Special Instruction, 3400 Cylinder Head To Block Joint Repair Procedure,
SEHS9564.

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Cylinder Liners

For Installation:

a. Put clean engine oil on cylinder block liner bore surfaces and rubber seals on the lower part of the liner.

b. Put the filler band completely in clean engine oil for a moment.

c. Install filler band (1) in the groove under the liner flange, without delay.

d. Install the liner in the bore immediately, before expansion of the filler band.

(1) Filler Band.

(2) O-Ring Seals.

(3) Thickness of flange on liner . . . 8.890 ± 0.020 mm (.3500 ± .0008 in)

"Use again" minimum thickness . . . 8.870 mm (.3492 in)

(4) Bore in liner (new) . . . 137.185 ± 0.025 mm (5.4010 ± .0010 in)

NOTE: Make reference to Guideline For Reusable Parts; Pistons And Cylinder Liners, SEBF8049 and SEBF8068.

NOTE: If there is a block erosion in the area of the cylinder liner O-rings, the block can be machined and an insert installed.

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Cylinder Liner Projection

NOTE: For more information on the tooling and procedures used for the Cylinder Liner Projection refer to the, Systems Operation, Testing
& Adjusting.

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Crankshaft

NOTE: For procedure on how to measure for a bent crankshaft, see Guideline for Reusable Parts, SEBF8030.

Typical Example

(1) Maximum length of pin out of crankshaft face . . . 8.4 mm (.33 in)

(2) Thrust plates for center main bearing only.

(3) End play for the crankshaft (new) . . . 0.13 to 0.50 mm (.005 to .020 in)

Maximum permissible end play with used bearings . . . 0.89 mm (.035 in)

(4) Minimum torque for six plugs . . . 23 N·m (17 lb ft)

"Stake" (make a mark with a punch) the crankshaft to hold the plug tight.

(5) Length of dowel out of the crankshaft . . . 4.1 ± 0.5 mm (.16 ± .02 in)

(6) Maximum permissible temperature of the gear for installation on the crankshaft . . . 205°C (400°F)

NOTE: Install gear with timing "V" mark to the outside.

(7) 2W1734 Seal Group (rear) installed on rear crankshaft gear.

(8) Make reference to Connecting Rod Bearing Journals.

(9) Make reference to Main Bearing Journals.

(10) 2W1733 Seal Group (front).

Copyright 1991, 2004 Caterpillar Inc.
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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Crankshaft Rear Gear

(1) Crankshaft rear sleeve.

(2) Crankshaft.

(3) Dimension from rear edge of sleeve to rear face of crankshaft . . . 1.5 ± 0.5 mm (.06 ± .02 in)

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Connecting Rod And Main Bearing Journals

Make reference to Guidelines For Reusable Parts, Main Bearings And Connecting Rod Bearings, SEBF8009 and Guidelines For Reusable
Parts, Crankshaft Measurement, SEBF8041.

Connecting Rod Bearing Journals

Clearance between bearing and journal (new) . . . 0.071 to 0.168 mm (.0028 to .0066 in)

Maximum permissible clearance between bearing and journal . . . 0.25 mm (.010 in)

Main Bearing Journals

Clearance between bearing and journal (new) . . . 0.091 to 0.186 mm (.0036 to .0073 in)

Maximum permissible clearance between bearing and journal . . . 0.25 mm (.010 in)

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Connecting Rods

(1) Bore in connecting rod for piston pin bearing . . . 55.436 ± 0.013 mm (2.1825 ± .0005 in)

Tight fit between connecting rod eye and piston pin bearing . . . 0.05 to 0.10 mm (.002 to .004 in)

NOTE: Connecting rod must be heated for installation of piston pin bearing. Do not use a torch.

Heat connecting rod for piston pin bearing installation to a temperature of . . . 177 to 260°C (350 to 500°F)
Positioning Pin Bearing

NOTE: Piston pin bearing junction and locating hole are 180 degrees apart (directly across from each other). Bearing junction and locating
hole must be assembled within either area "A" (90 ± 10 degrees from centerline through the connecting rod bores) as shown.

Make reference to Special Instruction SMHS7295 for use of pin bearing removal and installation tools and procedures.

(2) Bore in connecting rod for bearing with nuts tight to specifications (6) . . . 103.500 ± 0.013 mm (4.0748 ± .0005 in)

(3) Distance between center of bearings . . . 261.62 ± 0.05 mm (10.300 ± .002 in)

(4) Bore in bearing for piston pin (new) . . . 50.830 ± 0.008 mm (2.0012 ± .0003 in)

Diameter of piston pin (new) . . . 50.795 ± 0.005 mm (1.9998 ± .0002 in)

Maximum permissible clearance between bearing and piston pin (worn) . . . 0.08 mm (.003 in)

(5) Bore in bearing for crankshaft . . . 97.119 to 97.175 mm (3.8236 to 3.8258 in)

Clearance between bearing and crankshaft (new) . . . 0.071 to 0.168 mm (.0028 to .0066 in)

Maximum permissible clearance between bearing and crankshaft (worn) . . . 0.25 mm (.010 in)

NOTE: Bearings are available in 0.63 mm (.025 in) and 1.27 mm (.050 in) smaller than original size.
Marks For Tightening Connecting Rod Bolts

(6) Tightening procedure for connecting rod bolts:

a. Put clean engine oil on bolt threads and contact surfaces of nut and cap.

b. Tighten both nuts to . . . 80 ± 8 N·m (60 ± 6 lb ft)

c. Put a mark on each nut and end of bolt as shown.

d. Tighten each nut from mark . . . 120 ± 5 degrees

NOTE: The connecting rod must be installed so the chamfer on the edge of bore (5) is near the corner on the crankshaft. The side opposite
the chamfered edge must be against the other connecting rod on the same crankshaft pin.

Side clearance between two connecting rods on the same crankshaft pin (new) . . . 0.28 to 0.84 mm (.011 to .033 in)

NOTE: Make reference to Special Instruction GMG02394 & SMHS7366 for information to check and recondition connecting rods. Refer
to Guideline For Reusable Parts, Salvage Of Non-Serrated Connecting Rods, SEBF8064.

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Pistons And Rings

Make reference to Guideline For Reusable Parts; Pistons, SEBF8049; Cylinder Liners, SEBF8068; and Piston Pins And Retaining Rings,
SEBF8051.

Top And Intermediate Ring

The 1U6431 Keystone Piston Ring Groove Gauge is necessary for measuring ring grooves in keystone style pistons. For correct use of the
gauge group, see the instruction card that is with the gauge group.

Install piston rings with "UP" side toward top of piston.

(1) Install top ring with side marked "UP-1" toward top of piston and yellow color strip to right of ring end gap.

(2) Install intermediate ring with side marked "UP-2" toward top of piston and green color strip to right of ring end gap.

Clearance between ends of piston ring when installed in a cylinder liner with a bore size of 137.16 mm (5.400 in)

Top ring . . . 0.724 ± 0.190 mm (.0285 ± .0075 in)

Intermediate ring . . . 1.080 ± 0.190 mm (.0425 ± .0075 in)

Increase in clearance between ends of piston rings for each 0.03 mm (.001 in) increase in cylinder liner bore size . . . 0.08 mm (.003 in)

Oil Control Ring

(3) Install oil control ring with the gap in the spring 180 degrees away from the gap in the ring.
Width of groove in piston for piston ring (new) . . . 3.188 ± .013 mm (.1255 ± .0005 in)

Thickness of piston ring (new) . . . 3.137 ± 0.013 mm (.1235 ± .0005 in)

Clearance between groove and piston ring (new) . . . 0.073 ± 0.023 mm (.0029 ± .0009 in)

Clearance between ends of piston ring when installed in a cylinder liner with a bore size of 137.16 mm (5.400 in) . . . 0.572 ± 0.190 mm
(.0225 ± .0075 in)

Increase in clearance between ends of piston ring for each 0.03 mm (.001 in) increase in cylinder liner bore size . . . 0.08 mm (.0003 in)

Piston Pin Bore

(4) Bore in piston for pin . . . 50.814 ± 0.004 mm (2.0006 ± .0002 in)

Clearance between pin and bore in piston . . . 0.007 to 0.033 mm (.0003 to .0013 in)

Pin diameter . . . 50.795 ± 0.005 mm (1.9998 ± .0002 in)

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Flywheel Housing

4N2931

1. Tighten flywheel housing bolts with the procedure that follows:

a. Tighten bolts 1 through 20 in number sequence to a torque of . . . 40 ± 10 N·m (30 ± 7 lb ft)

b. Retighten bolts 1 through 20 in number sequence to a torque of . . . 55 ± 7 N·m (40 ± 5 lb ft)

NOTE: Front face of flywheel housing and rear face of block must be free of oil, dirt, water, assembly compounds and other contaminants
during assembly. With an authorized applicator, apply a continuous film of 9S3263 Thread Lock to entire joint face.

NOTE: Cut the gasket between the flywheel housing and the block flush with the bottom of the flywheel housing after assembly.
4N1890

(1) Tighten flywheel housing bolts with the procedure that follows:

a. Tighten bolts 1 through 17 in number sequence to a torque of . . . 40 ± 10 N·m (30 ± 7 lb ft)

b. Retighten bolts 1 through 17 in number sequence to a torque of . . . 40 ± 10 N·m (30 ± 7 lb ft)

(2) Maximum permissible change from an exact vertical face (face runout) at 4 points (total indicator reading) . . . 0.30 mm (.012 in)

NOTE: Front face of flywheel housing and rear face of block must be free of oil, dirt, water, assembly compounds and other contaminants
during assembly. With an authorized applicator, apply a continuous film of 9S3263 Thread Lock to entire joint face.

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Flywheel Adapter

Typical Illustration (7N6291 Shown)

6N9829, 7N6291

(1) Transmission flywheel.

Make reference to Flywheel Runout for the correct method of flywheel inspection.

(2) Gear. Maximum temperature for installation-install with chamfer toward outside . . . 316°C (600°F)

(3) Coupling Assembly.

(4) Torque for the bolts that hold the flywheel to the crankshaft:

6N9829 . . . 272 ± 27 N·m (200 ± 20 lb ft)

7N6291 . . . 285 ± 27 N·m (210 ± 20 lb ft)

NOTE: Put engine oil on threads and face of bolts before assembly.
For flywheel face runout, pilot bore runout and coupling pilot bore runout refer to the Flywheel Specification Chart.

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Flywheel

Typical Example

7N3060, 7N3079

NOTE: Make reference to Flywheel Runout in Systems Operation, Testing & Adjusting for the correct method of flywheel inspection.

(1) Torque for the bolts that hold the flywheel to the crankshaft . . . 270 ± 40 N·m (200 ± 30 lb ft)

NOTE: Put 4C5593 Anti-Seize Compound on threads and face of bolts before assembly.

(2) Ring gear. Install with chamfer toward outside. Maximum temperature for installation of ring gear on flywheel is 300°C (572°F).

For flywheel face runout, pilot bore runout, and coupling pilot bore runout see the Flywheel Specifications Chart.
Typical Illustration

6N1281, 6N1299, 4P3100

NOTE: Make reference to Flywheel Runout in Systems Operation, Testing & Adjusting for the correct method of flywheel inspection.

(1) Torque for the bolts that hold the flywheel to the crankshaft . . . 270 ± 40 N·m (200 ± 30 lb ft)

NOTE: Put 4C5593 Anti-Seize Compound on threads and face of bolts before assembly.

(2) Gear. Maximum temperature for installation (install with chamfer toward outside) . . . 316°C (600°F)

For flywheel face runout, pilot bore runout, and coupling pilot bore runout see the Flywheel Specifications Chart.
Typical Illustration

4W7370

NOTE: Make reference to Flywheel Runout in Systems Operation, Testing & Adjusting for the correct method of flywheel inspection.

(1) Torque for the bolts that hold the flywheel to the crankshaft . . . 270 ± 40 N·m (200 ± 30 lb ft)

NOTE: Put 4C5593 Anti-Seize Compound on threads and face of bolts before assembly.

(2) Gear. Maximum temperature for installation (install with chamfer toward outside) . . . 316°C (600°F)

For flywheel face runout, pilot bore runout, and coupling pilot bore runout see the Flywheel Specifications Chart.
Typical Illustration

3N8804

NOTE: Make reference to Flywheel Runout in Systems Operation, Testing & Adjusting for the correct method of flywheel inspection.

(1) Torque for the bolts that hold the flywheel to the crankshaft . . . 270 ± 40 N·m (200 ± 30 lb ft)

NOTE: Put 4C5593 Anti-Seize Compound on threads and face of bolts before assembly.

(2) Gear. Maximum temperature for installation (install with chamfer toward outside) . . . 316°C (600°F)

For flywheel face runout, pilot bore runout, and coupling pilot bore runout see the Flywheel Specifications Chart.
Typical Illustration

4P3070

NOTE: Make reference to Flywheel Runout in Systems Operation, Testing & Adjusting for the correct method of flywheel inspection.

(1) Torque for the bolts that hold the flywheel to the crankshaft . . . 270 ± 40 N·m (200 ± 30 lb ft)

NOTE: Put 4C5593 Anti-Seize Compound on threads and face of bolts before assembly.

(2) Gear. Maximum temperature for installation (install with chamfer toward outside) . . . 316°C (600°F)

For flywheel face runout, pilot bore runout, and coupling pilot bore runout see the Flywheel Specifications Chart.
Typical Illustration

128-8269

NOTE: Make reference to Flywheel Runout in Systems Operation, Testing & Adjusting for the correct method of flywheel inspection.

(1) Torque for the bolts that hold the flywheel to the crankshaft . . . 240 ± 40 N·m (180 ± 30 lb ft)

NOTE: Put 4C5593 Anti-Seize Compound on threads and face of bolts before assembly.

(2) Gear. Maximum temperature for installation (install with chamfer toward outside) . . . 316°C (600°F)

For flywheel face runout, pilot bore runout, and coupling pilot bore runout see the Flywheel Specifications Chart.
Copyright 1991, 2004 Caterpillar Inc.
All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Engine Front Support

(1) Tighten bolts to a torque of . . . 160 ± 30 N·m (120 ± 22 lb ft)

(2) Tighten bolts to a torque of . . . 45 ± 7 N·m (33 ± 5 lb ft)

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Pulley & Damper Group

8N5572

(1) Adapter.

(2) Damper.

(3) Tighten nuts to a torque of . . . 135 ± 20 N·m (100 ± 15 lb ft)

(4) Tighten studs to a torque of . . . 65 ± 10 N·m (48 ± 7 lb ft)

5N5322

(1) Damper.

(2) Pulley.

(3) Adapter.

(4) Tighten twelve bolts to a torque of . . . 130 ± 15 N·m (100 ± 10 lb ft)

9Y0651

(1) Tighten twelve studs to a torque of . . . 65 ± 10 N·m (48 ± 7 lb ft)

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Auxiliary Drive

Typical Illustration

4N8505, 7N8750, 7N8881

(1) Tighten nut to a torque of (except 4N8505) . . . 290 ± 10 N·m (210 ± 7 lb ft)

Lightly tap nut with hammer and retighten to . . . 290 ± 10 N·m (210 ± 7 lb ft)

(1) For 4N8505, tighten nut to a torque of . . . 203 ± 7 N·m (150 ± 5 lb ft)

(2) O-ring seal. Put a small amount of clean engine oil or glycerin in the bore for lubrication at assembly.

(3) Tighten nut to a torque of . . . 108 ± 7 N·m (81 ± 5 lb ft)

Tighten more if needed to make an alignment of the slots and bend tab of the lock on nut.

(4) Tighten the studs to a torque of . . . 30 ± 5 N·m (22 ± 4 lb ft)

(5) Distance bearing is from end of housing (except 4N8505) . . . 6.6 ± 0.5 mm (.26 ± .02 in)

(6) Seal. Install seal with the lip toward the bearing as shown. Put a small amount of clean engine oil on the lip of the seal as lubricant for
assembly.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Power Take-Off Adapter-Front

Typical Illustration

(1) Tighten bolt to a torque of . . . 115 ± 15 N·m (85 ± 11 lb ft)

(2) Tighten eight bolts to a torque of . . . 115 ± 15 N·m (85 ± 11 lb ft)

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Power Take-Off Clutch

Front

Typical Illustration (One plate clutch shown)

(1) Procedure for tightening clutch assembly on tapered shaft:

a. Tighten nut to a torque of . . . 41 N·m (30 lb ft)

b. Retighten nut an additional 60 to 90 degrees.

c. Lock in position by bending a section of the lock against a flat on the nut.

(2) Tighten nut to a torque of . . . 750 ± 68 N·m (551 ± 50 lb ft)

Rear
4P3069, 4P3126, 112-1718

(1) Torque for twelve bolts . . . 240 ± 40 N·m (175 ± 29 lb ft)

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Stub Shaft

(1) Crankshaft.

(2) Torque for bolts . . . 272 ± 27 N·m (200 ± 20 lb ft)

Put clean engine oil on threads of bolts before assembly.

(3) Flywheel.

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All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Jacket Water Heater

7E6247 (120/240VAC, 3000 Watts), 7E6248 (240/480VAC, 6000 Watts)

(1) Thermostat assembly. Thermostat adjustment range . . . 16 to 71°C (60 to 160°F)

(2) Coolant inlet.

(3) Coolant outlet.

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Magnetic Pickup

Typical Example

(1) Distance between end of magnetic pickup and gear . . . 0.56 to 0.84 mm (.022 to .033 in)

NOTE: This distance is set by turning magnetic pickup into threads until magnet is against the gear tooth while the engine is stopped. Now
back magnetic pickup out 1/2 turn ± 30 degrees and tighten nut (2) as follows.

(2) Nut. Tighten nut to a torque of . . . 45 ± 7 N·m (33 ± 5 lb ft)

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Alternator Mounting Group

Typical Illustration

(1) Torque for locknuts . . . 150 ± 20 N·m (110 ± 15 lb ft)

(2) V-Belt. See Belt Tension Chart for the correct adjustment before the adjustment screw locknuts are tightened.

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Alternator And Regulator

7G7889 Alternator (12V 60A)

NOTE: Load the battery with a carbon pile (4C4911 Battery Load Tester) to get the maximum alternator output.

Polarity . . . Negative Ground

Rotation . . . Either Direction

Minimum full load current at 5000 rpm . . . 60A

Minimum full load current at 1500 rpm . . . 22A

Output voltage . . . 14.0 ± 0.3V

(1) Shaft nut torque . . . 102 ± 7 N·m (75 ± 5 lb ft)

(2) Torque for positive terminal nut . . . 6.2 ± 0.6 N·m (55 ± 5 lb in)

(3) Torque for ground terminal nut . . . 2.25 ± 0.25 N·m (20 ± 2 lb in)

(4) Regulator.

Voltage Setting . . . No adjustment

Permissible voltage range . . . 13.7 to 14.3V

5N5692 Alternator (24V 45A)

NOTE: Load the battery with a carbon pile (4C4911 Battery Load Tester) to get the maximum alternator output.

Polarity . . . Negative Ground

Rotation . . . Either Direction

Minimum full load current at 5000 rpm . . . 42.3A

Minimum full load current at 2000 rpm . . . 15.8A

Output voltage . . . 28 ± 1V

(1) Shaft nut torque . . . 102 ± 7 N·m (75 ± 5 lb ft)

(2) Torque for positive terminal nut . . . 6.2 ± 0.6 N·m (55 ± 5 lb in)

(3) Torque for ground terminal nut . . . 2.25 ± 0.25 N·m (20 ± 2 lb in)

(4) Regulator.

Voltage setting . . . No adjustment

Permissible voltage range . . . 27 to 29V

3T6352 Alternator (24V 35A)

NOTE: Load the battery with a carbon pile (4C4911 Battery Load Tester) to get the maximum alternator output.

Polarity . . . Negative Ground

Rotation . . . Either Direction

Minimum full load current at 5000 rpm . . . 35A

Minimum full load current at 1500 rpm . . . 11A

Output voltage . . . 28 ± 1V

(1) Shaft nut torque . . . 102 ± 7 N·m (75 ± 5 lb ft)

(2) Torque for positive terminal nut . . . 6.2 ± 0.6 N·m (55 ± 5 lb in)

(3) Torque for the ground terminal nut . . . 2.25 ± 0.25 N·m (20 ± 2 lb in)

(4) Regulator.

Voltage setting . . . No adjustment

Permissible voltage range . . . 27 to 29V

3E7577 Alternator (24V 75A)

NOTE: Load the battery with a carbon pile (4C4911 Battery Load Tester) to get the maximum alternator output.

Polarity . . . Negative Ground

Rotation . . . Either Direction

Minimum full load current at 5000 rpm . . . 67A

Minimum full load current at 2000 rpm . . . 29A

Field current at rated voltage and 27°C (80°F) . . . 2.5 to 2.9A

(1) Torque for nut . . . 102 ± 7 N·m (75 ± 5 lb ft)

(2) Torque for output terminal . . . 14 ± 1 N·m (10 ± 1 lb ft)

Torque for the ground terminal nut . . . 6.2 ± 0.6 N·m (55 ± 5 lb in)

Regulator.

Voltage Setting . . . No Adjustment

 Permissible Voltage Range . . . 27 to 29V

3E7892 Alternator (12V 85A)

NOTE: Load the battery with a carbon pile (4C4911 Battery Load Tester) to get the maximum alternator output.

Polarity . . . Negative Ground

Rotation . . . Either Direction

Minimum full load current at 5000 rpm . . . 77A

Minimum full load current at 1500 rpm . . . 38A

Output voltage . . . 14 ± .5V

(1) Torque for nut . . . 102 ± 7 N·m (75 ± 5 lb ft)

(2) Torque for output terminal . . . 14 ± 1 N·m (10 ± 1 lb ft)

Torque for the ground terminal nut . . . 6.2 ± 0.6 N·m (55 ± 5 lb in)

Regulator.

Voltage Setting . . . No Adjustment

Permissible Voltage Range . . . 13.5 to 14.5V

7N9720 Alternator (24V 35A)

NOTE: Load the battery with a carbon pile (4C4911 Battery Load Tester) to get the maximum alternator output.

Polarity . . . Negative Ground

Rotation . . . Clockwise

Minimum full load current at 5000 rpm . . . 35A

Minimum full load current at 1500 rpm . . . 12A

Output voltage . . . 27.5 ± 1.0V

(1) Shaft nut torque . . . 102 ± 7 N·m (75 ± 5 lb ft)

(2) Regulator.

Voltage setting . . . No adjustment

Permissible voltage range . . . 26.5 to 28.5V

(3) Torque for positive terminal nut . . . 14 ± 1 N·m (10 ± 1 lb ft)

(4) Torque for ground terminal nut . . . 2.4 ± 0.4 (22 ± 3 lb in)
9G4574 Alternator (24V 35A)

NOTE: Load the battery with a carbon pile (4C4911 Battery Load Tester) to get the maximum alternator output.

Polarity . . . Negative Ground

Rotation . . . Either Direction

Minimum full load current at 5000 rpm . . . 35.6A

Minimum full load current at 1500 rpm . . . 15.8A

Output voltage . . . 28 ± 1V
(1) Shaft nut torque . . . 102 ± 7 N·m (75 ± 5 lb ft)

(2) Torque for positive terminal nut . . . 14 ± 1 N·m (10 ± 1 lb ft)

(3) Torque for ground terminal nut . . . 4.4 ± 1.0 N·m (39 ± 9 lb in)

(4) Regulator.

Voltage setting . . . No adjustment

Permissible voltage range . . . 27 to 29V

4N3986 Alternator (24V 60A)

NOTE: Load the battery with a carbon pile (4C4911 Battery Load Tester) to get the maximum alternator output.
Polarity . . . Negative Ground

Rotation . . . Either Direction

Minimum full load current at 5000 rpm . . . 54A

Minimum full load current at 1500 rpm . . . 19A

Output voltage . . . 27.5 ± 1.0V

(1) Shaft nut torque . . . 102 ± 7 N·m (75 ± 5 lb ft)

(2) Torque for output terminal . . . 7.1 ± .8 N·m (63 ± 7 lb in)

(3) Regulator.

Voltage Setting . . . No Adjustment

Permissible Voltage Range . . . 26.5 to 28.5V

4N3987 Alternator (32V 60A)

NOTE: Load the battery with a carbon pile (4C4911 Battery Load Tester) to get the maximum alternator output.

Polarity . . . Negative Ground

Rotation . . . Either Direction

Minimum full load current at 5000 rpm . . . 60A

Minimum full load current at 1500 rpm . . . 20A

Output voltage . . . 36.6 ± 1.5V

(1) Shaft nut torque . . . 102 ± 7 N·m (75 ± 5 lb ft)

(2) Torque for output terminal . . . 7.1 ± .8 N·m (63 ± 7 lb in)

(3) Regulator.

Voltage Setting . . . No Adjustment

Permissible Voltage Range . . . 35.1 to 38.1V

6T1395 Alternator (24V 35A)

NOTE: Load battery with a carbon pile (4C4911 Battery Load Tester) to get maximum alternator output.

Polarity . . . Negative Ground

Rotation . . . Either Direction

Minimum full load current at 5000 rpm . . . 27.9A

Minimum full load current at 1500 rpm . . . 10.8A

Output voltage . . . 28 ± 1V

(1) Shaft nut torque . . . 60 ± 7 N·m (44 ± 5 lb ft)

(2) Torque for three small terminal nuts . . . 2.25 ± 0.25 N·m (20 ± 2 lb in)

(3) Torque for large terminal nut . . . 6.2 ± 0.6 N·m (55 ± 5 lb in)

(4) Regulator.

Voltage setting . . . No Adjustment

Permissible voltage range . . . 27 to 29V

9X7803 Alternator (24V 100A)

NOTE: Load the battery with a carbon pile (4C4911 Battery Load Tester) to get the maximum alternator output.
Polarity . . . Negative Ground

Rotation . . . Either Direction

Minimum full load current at 5000 rpm . . . 94A

Minimum full load current at 2000 rpm . . . 9A

Output voltage . . . 27.5 ± 1V

(1) Tighten bolt to a torque of . . . 6.2 ± .6 N·m (55 ± 5 lb in)

(2) Shaft nut torque . . . 102 ± 7 N·m (75 ± 5 lb ft)

(3) Torque for output terminal . . . 7.1 ± .8 N·m (63 ± 7 lb in)

(4) Regulator.

Voltage Setting . . . No Adjustment

Permissible Voltage Range . . . 26.5 to 28.5V

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Staring Motors

Electric

6V0890 (24V), 6V0885 (24V), 6V0927 (24V)

Rotation as viewed from drive end . . . Clockwise

No load conditions at 25°C (77°F):

Speed . . . 6950 ± 1650 rpm

Current draw . . . 115 ± 25A

Voltage . . . 23V

Clearance between pinion and housing (pinion clearance) . . . 9.1 mm (.36 in)

(1) Torque for large terminal nuts . . . 30.5 ± 3.5 N·m (22 ± 3 lb ft)

(2) Torque for small terminal nuts . . . 2.25 ± 0.25 N·m (20 ± 2 lb in)

(3) Torque for screws holding nose housing to lever housing . . . 20.3 ± 2.7 N·m (15 ± 2 lb ft)

Solenoid
Current consumption (draw) at 25°C (77°F):

Pull in windings at 20V . . . 49.3 ± 3.3A

Hold in windings at 20V . . . 6.8A maximum

6V0501 (32V), 6V0508 (32V)

Rotation as viewed from drive end . . . Clockwise

No load conditions at 25°C (77°F):

Speed . . . 6500 ± 1000 rpm

Current draw . . . 87.5 ± 12.5A

Voltage . . . 30V

Clearance between pinion and housing (pinion clearance) . . . 9.1 mm (.36 in)

(1) Torque for large terminal nuts . . . 30.5 ± 3.5 N·m (22 ± 3 lb ft)

(2) Torque for small terminal nuts . . . 2.25 ± 0.25 N·m (20 ± 2 lb in)

(3) Torque for screws holding nose housing to lever housing . . . 20.3 ± 2.7 N·m (15 ± 2 lb ft)

Solenoid

Current consumption (draw) at 25°C (77°F):

Pull in windings at 32V . . . 41 ± 3.3A

Hold in windings at 32V . . . 6.3A maximum

8C3449 (24V)

Rotation as viewed from drive end . . . Clockwise

No load conditions at 25°C (77°F):

Speed . . . 7643 ± 1683 rpm

Current draw . . . 67.5 ± 7.5A

Voltage . . . 23V

Clearance between pinion and housing (pinion clearance) . . . 9.1 mm (.36 in)

(1) Torque for large terminal nuts . . . 30.5 ± 3.5 N·m (22 ± 3 lb ft)

(2) Torque for small terminal nuts . . . 2.25 ± 0.25 N·m (20 ± 2 lb in)

(3) Torque for motor frame terminal . . . 8 ± 3 N·m (70 ± 26 lb in)

Solenoid

Current consumption (draw) at 25°C (77°F):

Pull in windings at 20V . . . 56.5 ± 4.5A

Hold in windings at 20V . . . 14.6A

7T0795 (24V)

Rotation as viewed from drive end . . . Clockwise

No load conditions at 25°C (77°F):

Speed . . . 5500 rpm minimum

Current draw . . . 140A maximum

Voltage . . . 24V

(1) Torque for large terminal nuts . . . 30.5 ± 3.5 N·m (22 ± 3 lb ft)

(2) Torque for small terminal nuts . . . 2.25 ± 0.25 N·m (20 ± 2 lb in)

Solenoid

Current consumption (draw) at 25°C (77°F):

Pull in windings at 24V . . . 51A

Hold in windings at 24V . . . 7A

Air
4W5105, 4W5106

(1) Cover.

Tighten the bolts evenly in small increases until the torque is . . . 80 N·m (60 lb ft)

(2) Torque for bolts . . . 36 N·m (26 lb ft)

(3) Torque for bolt . . . 78 N·m (55 lb ft)

(4) Torque for bolt that holds piston . . . 110 N·m (80 lb ft)

(5) Rotor clamp nut.

Tighten nut until clearance between rear end plate and rotor is . . . 0.03 to 0.08 mm (0.001 to 0.003 in)

Check clearance again after the bolt for the clamp nut is tightened.

(6) Torque for bolt that holds rotor . . . 120 N·m (90 lb ft)
105-5080, 105-5081

(1) Tighten bolts in steps to a torque of . . . 30 ± 5 N·m (22 ± 4 lb ft)

(2) Clearance between rotor and end plate . . . 0.81 mm (.032 in)

(3) Tighten bolts in steps to a torque of . . . 11.3 N·m (8 lb ft)

Pressure Regulating Valve

Typical Example

(1) Adjusting screw.

(2) Inlet pressure . . . 1725 kPa (250 psi)

Maximum permissible inlet pressure . . . 3100 kPa (450 psi)

(3) Minimum outlet pressure . . . 620 kPa (90 psi)

Maximum outlet pressure . . . 1030 kPa (110 psi)

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Service Meter

(1) Lubricate seal with engine oil.

Engine rpm (1800 rpm for 60 minutes) . . . one count

Shaft rotation (from shaft end of service meter) . . . CCW

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Tachometer Calibration Chart

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Tachometer (Digital)

(1) Magnetic Pickup terminals.

(2) Calibration Control (under plug):

Tighten plug to a torque of . . . 0.6 ± 0.1 N·m (5 ± 1 lb in) See Calibration Chart for settings.

(3) Tighten two nuts to a torque of . . . 0.9 ± 0.1 N·m (8 ± 1 lb in)

General Specifications:

(a) Operating temperature range -20 to +85° C (-4 to +185° F)

(b) Tachometer must be accurate within ± .5 percent

(c) Input frequency range 75 to 9000 Hz

(d) Time required for display update

Maximum 1.0 second

Minimum .25 second

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Ammeter

3N5992
1W8914

Copyright 1991, 2004 Caterpillar Inc.

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38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Indicators

Fuel Pressure

4W0510
2W3687

NOTE: Pointer movement beyond point A of indicator band not permitted.

NOTE: Pointer must stop within +0.0 -2.0 mm (+.00 -.08 in) of point C.

Water Temperature
1W0700, 2W0417
4W2683
7W2061 Indicator 12V; Use with 5L7443 Sending Unit

Range . . . 38 to 116°C (100 to 240°F)

Test voltage . . . 13.8 ± 0.3V

Tolerance . . . ±0.76 mm (.03 in)

NOTE: Measure tolerance from the end of the pointer to the centerline of the mark on the face of the indicator.
7W2060 Indicator 24-32V; Use with 5L7442 Sending Unit

Range . . . 38 to 116°C (100 to 240°F)

Test voltage . . . 27.2 ± 0.3V

Tolerance . . . ±0.76 mm (.03 in)

NOTE: Measure tolerance from the end of the pointer to the centerline of the mark on the face of the indicator.

NOTE: For 32V systems the 5L7441 resistor (65 ohms) is used with this indicator.

Oil Pressure
2W3681 (Mechanical)

NOTE: Calibrating hole in dial face.

4W0506
7W2936 Indicator 12V; Use with 9X1124 Sending Unit

Range . . . 0 to 550 kPa (0 to 80 psi)

Test voltage . . . 13.8 ± 0.3V

Tolerance . . . ±0.8 mm (.03 in)

NOTE: Measure tolerance from the end of the pointer to the centerline of the mark on the face of the indicator.

7W2937 Indicator 24-32V; Use with 9X1124 Sending Unit

Range . . . 0 to 550 kPa (0 to 80 psi)

Test voltage . . . 27.2 ± 0.3V

Tolerance . . . ±0.8 mm (.03 in)

NOTE: Measure tolerance from the end of the pointer to the centerline of the mark on the face of the indicator.

NOTE: For 32V systems the 5L7441 resistor (65 ohms) is used with this indicator.

Differential Pressure

4W0508

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Sending Units

Water Temperature

5L7442 Sending Unit

Resistance at:

93°C (200°F) . . . 800 to 900 ohms

5L7443 Sending Unit

Resistance at:

38°C (100°F) . . . 403 to 493 ohms

71°C (160°F) . . . 118 to 138 ohms

104°C (220°F) . . . 44 to 49 ohms

Oil Pressure
Typical Illustration

9X1124 Sending Unit 12V, 24V or 32V

Resistance at:

0 kPa (0 psi) . . . 240 +17 - 13 ohms

138 kPa (20 psi) . . . 153.0 +9.5 - 11.0 ohms

552 kPa (80 psi) . . . 33.5 +16.0 - 12.0 ohms

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Switches

Liquid Level

NOTE: Switch shown in high level position.

(1) Approximate liquid level when switch activitates . . . 6.4 mm (.25 in)

Contact position is normally closed.

Temperature
2W8915

Terminal No. 1 is normally open below actuation temperature.

Terminal No. 2 is common.

Terminal No. 3 is normally closed below actuation temperature.

With a temperature increase of 98 ± 1.5°C (208 ± 2°F), terminal No. 1 closes and terminal No. 3 opens.

With a temperature increase of 91°C (196°F), terminal No. 1 opens and terminal No. 3 closes.

(1) Final torque for switch assembly . . . 52 ± N·m (38 ± 6 lb ft)

7C9365

Terminal No. 1 is normally open below actuation temperature.

Terminal No. 2 is common.

Terminal No. 3 is normally closed below actuation temperature.

With a temperature increase of 107 ± 1.5°C (225 ± 2°F), terminal No. 1 closes and terminal No. 3 opens.

With a temperature increase of 100°C (212°F), terminal No. 1 opens and terminal No. 3 closes.
(1) Final torque for switch assembly . . . 52 ± 8 N·m (38 ± 6 lb ft)

5N8857

Terminal A is normally open below actuation temperature.

Terminal B is common.

Terminal C is normally closed below actuation temperature.

With a temperature increase of 98 ± 1.5°C (208 ± 2°F), terminal A closes and terminal C opens.

With a temperature decrease of 91°C (196°F), terminal A opens and terminal C closes.

(1) Final torque for switch assembly . . . 52 ± 8 N·m (38 ± 6 lb ft)

2W8916

Terminal A is normally open below actuation temperature.

Terminal B is common.

Terminal C is normally closed below actuation temperature.

With a temperature increase of 92 ± 1.5°C (198 ± 2°F), terminal A closes and terminal C opens.

With a temperature decrease of 85°C (185°F), terminal No. A opens and terminal C closes.

(1) Final torque for switch assembly . . . 52 ± 8 N·m (38 ± 6 lb ft)

3N7442

Low Water Temperature Switch

Switch must open between . . . 24 and 29°C (75 and 84°F)

Switch must close between . . . 18 and 24°C (64 and 75°F)

8N1693 For Ether Aid

Switch must open between . . . 35 and 41°C (95 and 106°F)

Switch must close . . . 27°C (81°F min)

Final installation tighten screws to a torque of . . . 1.7 ± 0.2 N·m (15 ± 2 lb in)

Final torque for switch assembly . . . 40 ± 5 N·m (29 ± 4 lb ft)

Pressure
6T6652

When installing switch, tighten to a maximum of . . . 40 ± 5 N·m (29 ± 4 lb ft)

Terminal No. 1 is common.

Terminal No. 2 is normally open below 103 kPa (15 psi).

Terminal No. 3 is normally closed below 103 kPa (15 psi).

With pressure increase, terminal No. 2 closes and terminal No. 3 opens at . . . 158 ± 28 kPa (23 ± 4 psi)

With pressure decrease, terminal No. 2 opens and terminal No. 3 closes at . . . 124 ± 21 kPa (18 ± 3 psi)

Temperature range (operating) . . . -40 to 121°C (-40.0 to 250°F)

9X4276

When installing switch, tighten to a maximum of . . . 40 ± 5 N·m (29 ± 4 lb ft)

Terminal No. 1 is common.

Terminal No. 2 is normally open below 48 kPa (7 psi).

Terminal No. 3 is normally closed below 48 kPa (7 psi).

With pressure increase, terminal No. 2 closes and terminal No. 3 opens at . . . 93.0 ± 20.8 kPa (13.5 ± 3.0 psi)

With pressure decrease, terminal No. 2 opens and terminal No. 3 closes at . . . 68.9 ± 20.8 kPa (10.0 ± 3.0 psi)

Temperature range (operating) . . . -40 to 121°C (-40.0 to 250°F)

2L3402

Current rating:

24 volts DC . . . 4A

32 volts DC . . . 2A

With an increase in pressure, switch closes at . . . 20.7 to 27.6 kPa (3 to 4 psi)

7N5946, For use with time delay and shutdown systems

Circuit 1: normally closed

Circuit 2: normally open

With an increase in pressure, circuit 1 opens and circuit 2 closes at . . . 145 kPa (21 psi) max.

With a decrease in pressure, circuit 2 opens and circuit 1 closes at . . . 75 ± 20 kPa (11 ± 3 psi)
3N7443, Alarm or Shutoff

With an increase of pressure, switch operates at . . . 130 to 145 kPa (19 to 21 psi)

With a decrease of pressure, switch operates at . . . 105 to 110 kPa (15 to 16 psi)

Starter Magnetic

Pull in voltage a 25° C . . . 17 V

Current consumption (draw) both windings at 24V . . . 0.82 ± 0.06 A

Type duty . . . Intermittent

(1) Torque for large terminal nuts . . . 3.6 ± 0.4 N·m (31 ± 4 lb in)

(2) Torque for small terminal nuts . . . 1.7 ± 0.3 N·m (15 ± 3 lb in)

Copyright 1991, 2004 Caterpillar Inc.

All Rights Reserved.
38S21136 3412 INDUSTRIAL ENGINE Specification
Media Number SENR1136-00 Publication Date 1996/05/28 Update Date 1996/07/09

Circuit Breaker

Type . . . Automatic Reset

Nominal current rating . . . 12.5 A

Maximum voltage rating . . . 36 VDC

Torque for two screws . . . 1.7 ±0.2 N·m (15 ± 2 lb in)

Electric
5N8293 Shown (Typical Illustration)

7E7143, 5N8293, 1W1223, 2W6665

Voltage rating (except 7E7143) . . . 24/32V

7E7143 . . . 12V

Coil resistance at 25°C (77°F) (except 7E7143) . . . 3.3 to 4.1 ohms

7E7143 . . . 0.69 to 0.85 ohms

Energized to . . . shutoff

This solenoid must not be used in constant operation for more than 2.5 minutes or damage
may result.
(1) Torque for terminal nuts . . . 1.23 to 1.92 N·m (11 to 17 lb in)

(2) Distance from end of solenoid to end of plunger . . . 11.3 mm (.44 in)

(3) Tighten locknut to a torque of . . . 24 ± 7 N·m (18 ± 5 lb ft)

(4) Distance of plunger travel [start with dimension (2)] . . . 15.9 mm (.63 in)

(5) Spring:

5L8983 (For 5N8293 Shutoff Solenoid)

Length under test force . . . 31.75 mm (1.250 in)

Test force . . . 8.9 N (2.00 lb)

Free length after test . . . 57.15 mm (2.250 in)

Outside diameter . . . 44.45 mm (1.750 in)

7N9845 (For 2W6665, 1W1223, 7E7143 Shutoff Solenoid)

Length under test force . . . 31.09 mm (1.224 in)

Test force . . . 16.7 ± 1.3 N (3.75 ± .30 lb)

Free length after test . . . 78.75 mm (3.100 in)

Outside diameter . . . 44.45 mm (1.750 in)

(6) Distance from shaft shoulder to plunger plate:

5N8293 Shutoff Solenoid . . . 35.30 mm (1.390 in)

1W1223 & 7E7143 Shutoff Solenoids . . . 22.68 mm (.893 in)

2W6665 Shutoff Solenoid . . . 20.62 mm (.812 in)

4P0303 Shown

4P0303, 7W7787

Solenoid plunger.

Stop bolt.

Locknut.

Lockwire and seal.

Coil resistance at 25°C (77°F)

Pull-in coil . . . 0.560 ± .056 ohms

 Hold-in coil . . . 21.5 ± 2.2 ohms

Air

Typical Illustration

3N8164, 3N9118

NOTE: Put a small amount of clean engine oil or glycerin on the lip of seal (4) and in the bores for the O-ring seals at assembly.

(1) Distance bearing is installed below pipe surface . . . 0.25 ± 0.25 mm (.010 ± .010 in)

(2) Diameter of shaft . . . 15.80 ± 0.03 mm (.622 ± .001 in)

Bore in bearings . . . 15.88 mm (.625 in)

Bore in pipe for bearings . . . 18.263 ± 0.013 mm (.7190 ± .0005 in)

(3) Valve assembly shown in the "run" (open) position.

When the valve is closed a 0.08 mm (.003 in) feeler gauge must not fit between the valve and the bore in the pipe at any point.

(4) Seal. Install the seal with the tip of the seal toward the outside as shown.
(5) Diameter of shaft . . . 9.60 ± 0.03 mm (.378 ± .001 in)

Bore in the bearing . . . 9.80 ± 0.03 mm (.386 ± .001 in)

NOTE: Adjust shaft as needed to change spring tension until hold-in current consumption (draw) is less than 2A at shutdown.

(6) 135-4649 Torsion Spring:

Free length . . . 54.5 mm (2.15 in)

Outside diameter . . . 30.4 mm (1.20 in)

(7) 3N7848 Spring:

Length under test force . . . 22.86 ± 0.50 mm (.900 ± .020 in)

Test force . . . 4.0 N (.90 lb)

Free length after test . . . 35.6 ± 0.5 mm (1.40 ± .02 in)

Outside diameter . . . 18.8 ± 0.5 mm (.74 ± .02 in)

(8) Bracket assembly. Bracket assembly must be adjusted so valve assembly (3) is parallel to pipe bore within 2 degrees.

(9) 4N3890 Solenoid:

Voltage rating . . . 24V or 32V

Current consumption (draw):

Pull-in windings . . . 39.1A at 38.4V

Hold-in windings . . . .58A at 38.4V

Plunger travel . . . 11.7 ± 0.3 mm (.46 ± .01 in)

Distance from plunger face to flange face:

with solenoid energized* . . . 9.6 ± 0.5 mm (.38 ± .02 in)

with plunger extended . . . 21.28 ± 0.13 mm (.838 ± .005 in)

*The hold-in current consumption (draw) on engine must take less than 2A at shutdown.

(10) Diode assembly. Diode assembly required to suppress the back EMF voltage spike generated when the solenoid is turned off.

Copyright 1991, 2004 Caterpillar Inc.

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