A VOCATIONAL TRAINING

PROJECT REPORT
ON

“ENGINES & TRANSMISSION”

CONDUCTED AT

BHARAT COKING COAL LTD.

(A Subsidiary of Coal India Ltd.)
(SINIDIH CENTRAL EXCAVATION WORKSHOP-DHANBAD, JHARKHAND)
(ISO 9001:2008,ISO 14001:2004 & AS 4801/OHAS 18001)

SUBMITTED BY:

SHASHANK KUMAR

MECHANICAL ENGINEERING

ROLL. NO - 00719120

HALDIA INTITUTE OF TECHNOLOGY, HALDIA

(2019-2023)

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Table of Contents
1. ABOUT THE COMPANY .................................................................................................................................................... 7
2. What the Workshop consist of?...................................................................................................................................... 9
3. ENGINE .......................................................................................................................................................................... 10
4. Classification of Engines ................................................................................................................................................ 11
5. What is Compression-Ignition Engine? ......................................................................................................................... 12
6. Parts of the Diesel Engine and its function ...................................................................................................................... 13
6.1 Cylinder block .......................................................................................................................................................... 13
6.2 Cylinder Head .......................................................................................................................................................... 13
6.3 Crankcase ................................................................................................................................................................ 13
6.4Piston, Connecting Rod, Piston Rings and Gudgeon Pin .......................................................................................... 14
6.5 Crankshaft ............................................................................................................................................................... 15
6.6 Flywheel .................................................................................................................................................................. 15
6.7 Liners ....................................................................................................................................................................... 16
6.8 Gaskets .................................................................................................................................................................... 17
6.9 Rocker Arm.............................................................................................................................................................. 17
6.10 Oil Pump ................................................................................................................................................................ 17
6.11 Exhaust Manifold with Turbo Charger .................................................................................................................. 17
6.12 Water Pump .......................................................................................................................................................... 18
6.13 Oil Filters ............................................................................................................................................................... 18
6.14 Sump ..................................................................................................................................................................... 18
7. Dis-Assembly of Diesel Engine ...................................................................................................................................... 19
7.1 Engine Removal ....................................................................................................................................................... 19
7.2 Engine Dis-assembly ............................................................................................................................................... 19
8. Testing ........................................................................................................................................................................... 22
9. Transmission ................................................................................................................................................................. 23
10. Purpose of an Automatic Transmission .................................................................................................................... 24
11. How Automatic Transmission Works ........................................................................................................................ 25
Now how does this all work? ............................................................................................................................................ 26
What does a Torque Converter Clutch do? ...................................................................................................................... 28
Planetary Gearing ............................................................................................................................................................. 29
Machines & Tools used during training period: .................................................................................................................... 32
Bibliography .......................................................................................................................................................................... 32

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LIST OF FIGURES:

Figure 1: VIEW OF THE WORKSHOP ........................................................................................................................................ 9

Figure 2 : CYLINDER BLOCK ................................................................................................................................................... 13
Figure 3: CYLINDER HEAD...................................................................................................................................................... 13
Figure 4: PISTON ASSEMBLY ................................................................................................................................................. 14
Figure 5:CRANKSHAFT ........................................................................................................................................................... 15
Figure 6: FLYWHEEL .............................................................................................................................................................. 16
Figure 7:LINERS ..................................................................................................................................................................... 16
Figure 8: ROCKER ARM.......................................................................................................................................................... 17
Figure 9: EXHAUST MANIFOLD WITH TURBOCHARGER........................................................................................................ 18
Figure 10: SUMP……………………………………………………………………………………………………………………………………………………………..18
Figure 11: ENGINE REMOVAL & DID-ASSEMBLING………………………..………………………………………………………………………………..20
Figure 12: BLOCK CLEANING ................................................................................................................................................. 21
Figure 13: TRANSMISSION TESTING………………………………………….…..………………………………………………………………………………..22
Figure 14: ENGINE TESTING…………………………………………………………..………………………………………………………………………………..22
Figure 15:TORQUE CONVERTOR ........................................................................................................................................... 27
Figure 16: PLANETARY GEARSET………………………….………………………..………………………………………………………………………………..30

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 ACKNOWLEDGEMENT

I take this opportunity to express my profound gratitude and deep regards to my guide Mr. SANJEEV
KUMAR TRIPATHI (MANAGER, EXCAVATION, BCCL) for his exemplary guidance, monitoring and
constant encouragement throughout the training. The blessing, help and guidance given by him time to time
shall carry me a long way in the journey of life on which I am about to embark.

I also take this opportunity to express a deep sense of gratitude to all the Engineers of the workshop (BCCL),
from which the valuable information and guidance, helped me in completing this task through various stages.

I am obliged to staff members of Bharat Coking Coal Limited for the valuable information provided by them
in their respective fields. I am grateful for their cooperation during the period of my training.

Lastly, I thank almighty, my parents and friends for their constant encouragement without which this
assignment would not be possible.

SHASHANK KUMAR

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 DECLARATION

I SHASHANK KUMAR a student of Mechanical Engineering of HALDIA INSTITUTE OF TECHNOLOGY

declare that this project has been done after the completion of my vocational training dated 24/11/2022 –
04/01/2023 on the topic “ENGINE & TRANSMISSION” under the guidance of Mr. Sanjeev Kumar Tripathi
(Manager, Engine Section), Krishna Kumar (Manager, Transmission Section) at BCCL (Excavation Workshop
– Sinidih, Dhanbad).

SHASHANK KUMAR

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1. ABOUT THE COMPANY:

Bharat Coal Coking Ltd. (BCCL) is a subsidiary of Coal India Limited with its headquarters
in Dhanbad, India. It was incorporated in January, 1972 to operate coking coal mines (214 in number)
operating in the Jharia and Raniganj Coalfields, taken over by the government of India on 16th Oct, 1971.

The company operates 81 coal mines which include 40 underground, 18 opencast and 23 mixed mines at
April 2010. The company also runs six coking coal washeries, two non-coking coal washeries, one
captive power plant (2 by 10 megawatt), and five by-product coke plants. The mines are grouped into 13
areas for administration purposes.

BCCL is the major producer of prime coking coal (raw and washed) in India. Medium coking coal is
produced in its mines in Mohuda and Barakar areas. In addition to production of hard coke, BCCL
operates washeries, sand gathering plants, a network of aerial ropeways for transport of sand, and a coal
bed methane-based power plant in Moonidih.

There are 12 areas in BCCL:

Administrative
Name
area

Area No 1 Barora Area

Area No 2 Block II Area

Area No 3 Govindpur Area

Area No 4 Katras Area

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 Area No 5 Sijua Area

Area No 6 Kusunda Area

Putki Balihari
Area No 7
Area

Area No 9 Bastacolla Area

Area No 10 Lodna Area

Eastern Jharia
Area No 11
Area

Chanch Victoria
Area No 12
Area

Area No 13 Western Jharia

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2. What the Workshop consist of?

The Workshop consist of Engine Section, Transmissions Section, Machine Shop, Electrical Section and
store deals with the repairing, maintenance and overhauling of the company’s heavy earthmovers like
dozers, payloaders, hall packs, dumpers shovels, drills etc. engines and transmission.

The Workshop is well equipped with modern machinery like over headed cranes, crankshaft grinding
machines, advanced tools to carry out the repair and maintenance work.

Figure 1: VIEW OF THE WORKSHOP

The workshop consists of series of engines and transmissions. The main brands of the engines are as
follow:

1. CUMMINS
2. CAT
3. KOMATSU

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3. ENGINE:

An engine is a machine designed to convert energy into useful mechanical motion. Heat engines,
including internal combustion engines and external combustion engines (such as steam engines) burn
a fuel to create heat which then produces motion.

"Engine" was originally a term for any mechanical device that converts force into motion. Most
mechanical devices invented during the industrial revolution were described as engines—the steam engine
being a notable example.

In modern usage, the term engine typically describes devices, like steam engines and internal combustion
engines, that burn or otherwise consume fuel to perform mechanical work by exerting a torque or linear
force to drive machinery that generates electricity, pumps water, or compresses gas. In the context of
propulsion systems, an air-breathing engine is one that uses atmospheric air to oxidise the fuel rather than
supplying an independent oxidizer, as in a rocket.

When the internal combustion engine was invented, the term "motor" was initially used to distinguish it
from the steam engine—which was in wide use at the time, powering locomotives and other vehicles such
as steam rollers. "Motor" and "engine" later came to be used interchangeably in casual discourse.
However, technically, the two words have different meanings. An engine is a device that burns or
otherwise consumes fuel, changing its chemical composition, whereas a motor is a device driven by
electricity, which does not change the chemical composition of its energy source.[3]

A heat engine may also serve as a prime mover ,a component that transforms the flow or changes in
pressure of a fluid into mechanical energy.

An automobile powered by an internal combustion engine may make use of various motors and pumps,
but ultimately all such devices derive their power from the engine. Another way of looking at it is that a
motor receives power from an external source, and then converts it into mechanical energy, while an
engine creates power from press.

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4. Classification of Engines:

1. Classification based on fuel used:

(a) Petrol Engine
(b) Diesel Engine
(c) Gas Engine
2. Classification based on no. of strokes:
(a) Four Stroke Engine
(b) Two Stroke Engine
3. Classification based on type of ignition:
(a) Spark Ignition Engine
(b) Compression Ignition Engine
4. Classification based on arrangement of cylinders:
(a) Vertical Engine
(b) Horizontal Engine
(c) Radial Engine
(d) V-Engine
5. Classification based on Valve arrangement:
(a) L-Head Arrangement
(b) I-Head Arrangement
(c) F-Head Arrangement
(d) T-Head Arrangement
6. Classification based on type of cooling:
(a) Air Cooled Engine
(b) Water Cooled Engine
(c) Evaporation Cooling Engine

The workshop mainly deals with Compression ignition engines that uses diesel as its fuel, and inline
cylinder arrangements and v-type cylinder arrangements are mostly repaired and maintained here in the
workshop.

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5. What is Compression-Ignition Engine?

Compression-ignition (CI) engines, also known as diesel engines, are ubiquitous prime movers with many
commercially important applications (motor vehicles, marine, locomotive, off-highway mobile
machinery). Rudolf Diesel in Germany invented and ran his first CI engine in 1893, intended to replace
lower-efficiency external combustion steam engines for stationary uses.

A form of internal-combustion heat engine that converts fuel energy to useful mechanical work, the CI
engine relies on high compression ratios (15 to 25:1, with most around 16-20:1) to heat the intake air by
compression to around 550 C (or 1,022 F) to ignite fuel typically injected just before top dead center
(TDC) of the piston stroke. CI engines will run on a variety of hydrocarbon fuels, from aromatics such as
gasoline to heavy carbon-rich fuel oil, as well as biological-based fuels (vegetable oils). For motor vehicle
CI engines today, all injection is direct into the combustion chamber by an electronically-controlled very
precise valve (which varies opening timing/duration) with either electric solenoid or piezoelectric
actuators. The preferred fuel injection layout today for highway diesels is common rail, which relies on a
pump to pressurize fuel in a common manifold or rail feeding all injectors. In other CI engine applications
(such as off-road machinery), unit injectors with a mechanical pump for each cylinder are used.

The typical injection pressures today are around 2000 bar (1 bar = 1 atmosphere = 14.6 psi), heading
toward 2500 bar, with experimental installations running at 3000 bar. At such pressures, the fuel spray
becomes quickly well atomized into tiny droplets that first vaporize on their surfaces in the hot air, and
then ignite. When the fuel is ignited, a large (and noisy) pressure rise suddenly occurs in the combustion
chamber (producing the characteristic diesel knock), typically reaching around 600 psi levels, well above
peak cylinder pressures in spark-ignited gasoline engines (around 200 psi). The electronic fuel injection
system is easily the most expensive item going into a new CI engine. For comparison, gasoline electronic
fuel injection systems are much simpler and less expensive: pressures are only 4-5 bar (port injection)
using solenoid injectors, and around 200 bar for direct injection (which is rising in popularity).
Accordingly, a diesel engine will cost much more than a gasoline engine of the same power level.

The result of such high diesel compression is that most of the internal moving parts and engine structures
everywhere must be “beefed up” to handle the high stress. For the same power output and/or displacement
levels, CI engines are much heavier than gasoline counterparts. Although that can render sluggish
acceleration on the highway, one upside is a much longer lasting engine. In the motor vehicle industry, the
expectation for engine overhaul intervals is around 150,000 miles for gasoline, 350,000 miles for light-
medium duty diesels and 500,000+ miles for HD diesels in trucks and buses. The longer life and enhanced
reliability of CI engines (compared to gasoline engines) is related to their overbuilt nature, lower
operating speeds, lubricity of the fuel oil, and lack of a spark-ignition system. The lower vapor pressure of
diesel fuel accords additional safety benefits, especially important in marine engine compartments.

For highway use, all CI engines today are turbocharged which, harnesses waste energy in the exhaust to
compress intake air. Unlike gasoline engines subject to detonation of the air-fuel mixture, CI engines have
no upper limit on intake manifold air pressure—up to failure of engine parts (like blowing a head gasket).
Turbocharger technology increases the specific power (hp or kw/liter of displacement) of CI engines by at
least 50 percent.

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6. Parts of the Diesel Engine and its function:
6.1 Cylinder Block: A cylinder block is an integrated structure comprising the cylinder(s) of
a reciprocating engine and often some or all of their associated surrounding structures (coolant passages,
intake and exhaust passages and ports, and crankcase). The term engine block is often
used synonymously with "Cylinder Block" .In the basic terms of machine elements, the various main
parts of an engine (such as cylinder(s), cylinder head(s), coolant passages, intake and exhaust passages,
and crankcase) are conceptually distinct, and these concepts can all be instantiated as discrete pieces
that are bolted.

Figure 2 : CYLINDER BLOCK

6.2 Cylinder Head: The cylinder head (often informally abbreviated to just head) sits above
the cylinders on top of the cylinder block. It closes in the top of the cylinder, forming the combustion
chamber. This joint is sealed by a head gasket. In most engines, the head also provides space for the
passages that feed air and fuel to the cylinder, and that allow the exhaust to escape. The head can also be
a place to mount the valves, spark plugs, and fuel injectors.

Figure 3: CYLINDER HEAD

6.3 Crankcase: The crankcase is the housing for the crankshaft. The enclosure forms the largest cavity in
the engine and is located below the cylinder, which in a multicylinder engine are usually integrated into
one or several cylinder blocks. Crankcases have often been discrete parts, but more often they are
integral with the cylinder bank, forming an engine block. Nevertheless, the area around the crankshaft is
still usually called the crankcase. Crankcases and other basic engine structural components (e.g.,
cylinders, cylinder blocks, cylinder heads, and integrated combinations thereof) are typically made
of cast iron or cast aluminium via sand casting.

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 6.4 Piston, Connecting Rod, Piston Rings and Gudgeon Pin:
a. Piston: A piston is a component of reciprocating engines. It is the moving component that is
contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to transfer
force from expanding gas in the cylinder to the crankshaft via a piston rod and/or connecting rod.
In a pump, the function is reversed and force is transferred from the crankshaft to the piston for the
purpose of compressing or ejecting the fluid in the cylinder. In some engines, the piston also acts as
a valve by covering and uncovering ports in the cylinder wall.
b. Connecting Rod: In a reciprocating piston engine, the connecting rod or conrod connects
the piston to the crank or crankshaft. Together with the crank, they form a simple mechanism that
converts reciprocating motion into rotating motion. Connecting rods may also convert rotating
motion into reciprocating motion.
c. Gudgeon Pin: The gudgeon pin connects the piston to the connecting rod and provides a bearing
for the connecting rod to pivot upon as the piston moves.
d. Piston Ring: A piston ring is a split ring that fits into a groove on the outer diameter of a piston.
The three main functions of piston rings in reciprocating engines are:
i. Sealing the combustion chamber so that there is no transfer of gases from the combustion
chamber to the crank.
ii. Supporting heat transfer from the piston to the cylinder wall.
iii. Regulating engine oil consumption.

The gap in the piston ring compresses to a few thousandths of an inch when inside the cylinder bore.

Figure 4: PISTON ASSEMBLY

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 6.5 Crankshaft: The crankshaft, sometimes abbreviated to crank, is the part of an engine that
translates reciprocating linear piston motion into rotation. To convert the reciprocating motion into
rotation, the crankshaft has "crank throws" or "crankpins", additional bearing surfaces whose axis is
offset from that of the crank, to which the "big ends" of the connecting rods from each cylinder attach.It
is typically connected to a flywheel to reduce the pulsation characteristic of the four-stroke cycle, and
sometimes a torsional or vibrational damper at the opposite end, to reduce the torsional vibrations often
caused along the length of the crankshaft by the cylinders farthest from the output end acting on the
torsional elasticity of the metal.

Figure 5:CRANKSHAFT

6.6 Flywheel: A flywheel is a rotating mechanical device that is used to store rotational energy. Flywheels
have a significant moment of inertia and thus resist changes in rotational speed. The amount of energy
stored in a flywheel is proportional to the square of its rotational speed. Energy is transferred to a
flywheel by applying torque to it, thereby increasing its rotational speed, and hence its stored energy.
Conversely, a flywheel releases stored energy by applying torque to a mechanical load, thereby
decreasing its rotational speed.

Three common uses of a flywheel include:

• They provide continuous energy when the energy source is discontinuous. For example,
flywheels are used in reciprocating engines because the energy source, torque from the engine, is
intermittent.

• They deliver energy at rates beyond the ability of a continuous energy source. This is achieved
by collecting energy in the flywheel over time and then releasing the energy quickly, at rates that
exceed the abilities of the energy source.

• They control the orientation of a mechanical system. In such applications, the angular
momentum of a flywheel is purposely transferred to a load when energy is transferred to or from
the flywheel.

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 Figure 6: FLYWHEEL

6.7 Liners:
a) Dry liners - Dry liner is made in the shape of barrel having a flange at the top which keeps it into
position in the cylinder block. The entire outer surface of the dry liner bears against the cylinder block
casting and hence must be machined very accurately from the outside also. Thus it is not in direct
contact with the cooling water and hence is known as dry liner. Its thickness ranges from 1.5mm to
3mm. It is used mostly for reconditioning warm cylinders.
b) Wet liners - A Wet liner forms a complete cylinder barrel. It is provided with a flange at the top which
fits into the groove in the cylinder block. At the bottom either the block or the liner is provided with
grooves, generally three in numbers, in which the packing rings made of rubber are inserted. The liner is
in direct contact with the cooling water and hence is known as wet liner. The outer surface of the liner
does not require accurate machining. Wet liners are thicker than dry liners, ranging from 1.5mm to 6mm

Figure 7:LINERS

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 6.8 Gaskets: A gasket is a mechanical seal which fills the space between two or more mating surfaces,
generally to prevent leakage from or into the joined objects while under compression. Gaskets
allow "less-than-perfect" mating surfaces on machine parts where they can fill irregularities. Gaskets are
commonly produced by cutting from sheet materials. Gaskets for specific applications, such as high-
pressure steam systems, may contain asbestos. However, due to health hazards associated with asbestos
exposure.

6.9 Rocker Arm: The rocker arm is an oscillating lever that conveys radial movement from the cam lobe
into linear movement at the poppet valve to open it. One end is raised and lowered by a rotating lobe of
the camshaft while the other end acts on the valve stem. When the camshaft lobe raises the outside of the
arm, the inside presses down on the valve stem, opening the valve. When the outside of the arm is
permitted to return due to the camshaft’s rotation, the inside rises, allowing the valve spring to close the
valve. The drive cam is driven by the camshaft. This pushes the rocker arm up and down about
the trunnion pin or rocker shaft. Friction may be reduced at the point of contact with the valve stem by a
roller cam follower.

Figure 8: ROCKER ARM

6.10 Oil Pump: The oil pump in an internal combustion engine circulates engine oil under pressure to the
rotating bearings, the sliding pistons and the camshaft of the engine. This lubricates the bearings,
allows the use of higher-capacity fluid bearings and also assists in cooling the engine. As well as its
primary purpose for lubrication, pressurized oil is increasingly used as a hydraulic fluid to power
small actuators. One of the first notable uses in this way was for hydraulic tappets in camshaft and
valve actuation. Increasingly common recent uses may include the tensioner for a timing belt
or variators for variable valve timing systems.

6.11 Exhaust manifold with turbo charger: A turbocharger, is a forced induction device used to
allow more power to be produced by an engine of a given size. A turbocharged engine can be more
powerful and efficient than a naturally aspirated engine because the turbine forces more air, and
proportionately more fuel, into the combustion chamber than atmospheric pressure alone.

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 Figure 9: EXHAUST MANIFOLD WITH TURBOCHARGER

6.12 Water Pump: A centrifugal pump is a rotodynamic pump that uses a rotating impeller to increase
the pressure and flow rate of a fluid. Centrifugal pumps are the most common type of pump used to
move liquids through a piping system. The fluid enters the pump impeller along or near to the
rotating axis and is accelerated by the impeller, flowing radially outward or axially into a diffuser
or volute chamber, from where it exits into the downstream piping system. Centrifugal pumps are
typically used for large discharge through smaller heads. Centrifugal pumps are most often
associated with the radial-flow type. However, the term "centrifugal pump" can be used to describe
all impeller type rotodynamic pumps including the radial, axial and mixed-flow variations.

6.13 Oil Filters: An oil filter is a filter designed to remove contaminants from engine oil, transmission
oil, lubricating oil, or hydraulic oil.

6.14 Sump: The bottom half of the crankcase is called the oil pan or sump. It is bolted or screwed to the
lower flange of the main casting of IC engine and usually is made of pressed steel or aluminium. Oil
pan serves as the reservoir for the storage, cooling, and ventilation of engine lubricating oil.
The plane of the joint between the crankcase and the oil pan may be either on the level of the
crankshaft axis or it may be lower. If it is on the level of the crankshaft axis, it will increase the
bottom oil pan portion. If it is lower than this axis, it will increase upper portion of the crankcase
thus increasing rigidity.

Figure 10: SUMP

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7. Dis-Assembly of Diesel Engine:

a) Engine Removal:
I. Drain the cooling system by opening the drain cock.
II. Disconnect the battery at positive terminal to avoid possibility of short circuit.
III. Disconnect the fuel tank line by unscrewing the connecting nut.
IV. Plug the fuel line to prevent leakage.
V. Remove the radiator stay bar.
VI. Remove the radiator.
VII. Remove the starting motor.
VIII. Disconnect the oil pressure and temperature sending unit wires at the units.
IX. Disconnect the exhaust pipe at the exhaust manifold by removing the stud nuts.
X. Remove the two nuts and bolts from each engine support. Disconnect the engine ground
strap. Remove the Engine supports.
XI. Remove two-cylinder head bolts. Fit a suitable engine lifting bracket in place and re-
tighten the cylinder head bolts previously removed. Attach the engine lifting bracket to a
lifting devices like mobile cranes etc. Take up all slacks.
XII. Separate the transmission section from the engine rear side.
XIII. Lift the Engine from the vehicle.

b) Engine Dis-Assembly: For disassembling the engine it is mounted on a suitable engine repair
stand. Priority to safety, principle should be adapted to avoid accidents.
Now the engine is out of the vehicle in the workshop and the lube oil is drained by opening a drain
nut.
I. Remove the water pump by unscrewing the bolts attached to the engine block.
II. Remove the exhaust manifold along with turbocharger.
III. Remove oil filter tube.
IV. Remove thermostat.
V. Remove crankshaft pulley and vibration damper.
VI. Remove intake manifold.
VII. Remove cylinder head.
VIII. Remove timing gear cover.
IX. Remove flywheel.
X. Remove flywheel housing.
XI. Remove the fuel pump and all other pipe connections.
XII. Remove camshaft.
XIII. Remove the sump by lifting the engine with a overhead crane.
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 XIV. Remove the oil pump (gear type) and its connections to the block.
XV. Now invert the engine by min. 90 degrees to access to the crankshaft and con. Rod portion.
XVI. Unscrew the bolts of piston and connecting rods on crankshaft i.e., big-end bearing bolts and
also main bearing bolts so as to remove the crankshaft. Thus, the crankshaft is lifted and
removed and further sent for inspection.
XVII. Now the piston is removed and inspected carefully to find any defects if there.
XVIII. The liner which acts as the guide for piston and cools the piston is removed by hammering
process and after removal is sent for inspection, mostly the liners are replaced.

Figure 11: ENGINE REMOVAL & DIS-ASSEMBLING

After disassembling the engine, the head sections turn out for inspecting the head of the engine, to check
for any leakages if there. Springs, Rocker arms, Push Rods, Levers are inspected to ensure the quality of
repair work. The block, the intake manifold, head, sump, flywheel housing, flywheel, timing gear
housing etc. parts are sent for cleaning, where high water pressure, air pressure and diesel is sprayed to
ensure for clean parts. The diesel is sprayed in the galleries for oil path inside the block or head and also
inside the thread to remove all the blockages if any. These blockages could lead the engine to seize if
brought in operation without cleaning.

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 Figure 12: BLOCK CLEANING

After the full inspection of the engine by the inspecting team the parts to be changed are enlisted and
attached to the Manager’s desk for approval. After the approval the parts of the supporting company are
issued from the store and the engine is again set on the workshop floor for assembling.

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8. Testing:
After the assembling the Engine is sent for testing where the engine is tested before being sent to the field
work. Engine noise, oil pressure, its temperature, power etc. are tested.

Figure 13: TRANSMISSION TESTING

Figure 14: ENGINE TESTING

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9. Transmission:

Transmission is the act of passing something on in another place. A machine consists of a power source
and a power transmission system, which provides controlled application of the power. Merriam-Webster
defines transmission as an assembly of parts including the speed-changing gears and the propeller shaft by
which the power is transmitted from an engine to a live axle. Often transmission refers simply to
the gearbox that uses gears and gear trains to provide speed and torque conversions from a rotating power
source to another device. The transmission generally is connected to the engine crankshaft via a flywheel
and/or clutch and/or fluid coupling. The output of the transmission is transmitted via driveshaft to one or
more differentials, which in turn, drive the wheels.

The workshop deals with the following series of automatic transmission:

1. CLBT-754
2. CLT-74
3. D15TR
4. D355
5. HD-78-2
6. D15 TC

An automatic transmission that selects an appropriate gear ratio without any operator intervention. They
primarily use hydraulics to select gears, depending on pressure exerted by fluid within the transmission
assembly. Rather than using a clutch to engage the transmission, a torque converter is placed in between
the engine and transmission. It is possible for the driver to control the number of gears in use or select
reverse, though precise control of which gear is in use may or may not be possible.

Automatic transmissions are easy to use. However, in the past, automatic transmissions of this type
have had a number of problems; they were complex and expensive, sometimes had reliability problems
(which sometimes caused more expenses in repair), have often been less fuel-efficient than their manual
counterparts (due to "slippage" in the torque converter), and their shift time was slower than a manual
making them uncompetitive for racing. With the advancement of modern automatic transmissions this
has changed.

Attempts to improve fuel efficiency of automatic transmissions include the use of torque converters that
lock up beyond a certain speed or in higher gear ratios, eliminating power loss, and overdrive gears that
automatically actuate above certain speeds. In older transmissions, both technologies could be intrusive,
when conditions are such that they repeatedly cut in and out as speed and such load factors as grade or
wind vary slightly.

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10. Purpose of an Automatic Transmission:

Just like that of a manual transmission, the automatic transmission's primary job is to allow the engine to
operate in its narrow range of speeds while providing a wide range of output speeds.

Without a transmission, cars would be limited to one gear ratio, and that ratio would have to be selected to
allow the car to travel at the desired top speed. If you wanted a top speed of 80 mph, then the gear ratio
would be like third gear in most manual transmission cars.

You have probably never tried driving a manual transmission car using only third gear. If you did, you
would quickly find out that you had almost no acceleration when starting out, and at high speeds, the
engine would be screaming along near the red-line. A car like this would wear out very quickly and would
be nearly undriveable.

So, the transmission uses gears to make more effective use of the engine's torque, and to keep the engine
operating at an appropriate speed. When towing or hauling heavy objects, your vehicle's transmission can
get hot enough to burn up the transmission fluid. In order to protect the transmission from serious damage,
drivers who tow should buy vehicles equipped with transmission coolers.

The key difference between a manual and an automatic transmission is that the manual transmission locks
and unlocks different sets of gears to the output shaft to achieve the various gear ratios, while in an
automatic transmission, the same set of gears produces all of the different gear ratios. The planetary
gearset is the device that makes this possible in an automatic transmission.

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11. How Automatic Transmission works?

There are five major parts in a modern torque converter, they are from top to bottom:

1. impeller/cover assembly (also called a pump)

2. stator
3. turbine
4. torque converter clutch
5. Turbine

Imagine two fans side by side, and one of the fans blowing air into the other, this is how a torque
converter works, except it does this with an actual fluid in a contained housing. The air pushed off the
blades of one fan, will strike the blades of the fan next to it and spin it.

The impeller (first piece) is attached to the donut shape on the inside of the converter, and is driven by the
engine as it is welded to the inside of the converter, which is bolted to a drive plate or flexes plate.
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 The turbine is the other set of blades opposite of the impeller, and is driven by the displaced oil from it. This
piece is splined to the transmission input shaft and is driven by the impeller, this operates similar to a
manual transmission clutch disc.

The stator resides in the very center of the torque converter. Its job is to redirect the fluid returning from the
turbine before it hits the pump again. This dramatically increases the efficiency of the torque converter.

The stator has a very aggressive blade design that almost completely reverses the direction of the fluid. A
one-way clutch (inside the stator) connects the stator to a fixed shaft in the transmission (the direction that
the clutch allows the stator to spin is noted in the figure above). Because of this arrangement, the stator
cannot spin with the fluid -- it can spin only in the opposite direction, forcing the fluid to change direction as
it hits the stator blades.

Something a little bit tricky happens when the car gets moving. There is a point, around 40 mph (64 kph), at
which both the pump and the turbine are spinning at almost the same speed (the pump always spins slightly
faster). At this point, the fluid returns from the turbine, entering the pump already moving in the same
direction as the pump, so the stator is not needed

The flex plate (or drive plate) flexes during torque multiplication, and is the result of the impeller pushing
oil on the turbine and the stator pushing the same oil back into the impeller, causing the two to repel sightly,
and the flex plate to flex in turn. It helps dampen the ride by allowing this movement to occur.

Now how does this all work?

The transmission oil pump is always driven by the engine, through an auxiliary shaft. Pump oil will fill
the torque converter up, and the fluid will be forced through the blades of the impeller due to centrifugal
rotation of the converter via engine rotation. This fluid force is curved by the impeller blades to strike the
blades of the turbine at a specific angle to provide sufficient power to turn the transmission.

Once the oil forces the turbine to turn, it has to go somewhere, and since the turbine is basically the opposite
in design, it flows back downward towards the center. Just opposite of the impeller, which brings oil in from
the center and throws it outward. If the turbine were allowed to exhaust its oil into the center uncontrolled, it
would create a huge turbulence inside, and create vibrations and lots of heat. This is where the stator comes
in. Its job is to redirect the fluid from the turbine, back into the impeller, which creates a pressure. This
piece is only functional when the impeller and turbine are not turning the same speed, as the speed

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 difference is what causes the turbulence. When the shafts are turning close to the same as one another, the
stator freewheels, as both blades are turning similar enough for the turbine fluid to enter the impeller again,
without the need to redirect it.

Figure 15: TORQUE CONVERTOR

There are two types of flow in a torque converter, vortex flow, and rotary flow.

Vortex Flow is the flow of fluid through the blades when the two blade speeds are different, like the
engine is turning 4500rpm (which is the speed of the impeller as well) and the transmission input shaft
(turbine) is only turning 3000rpm. This causes turbulence and is where the stator does its job by
redirecting the fluid back to the source, to multiply engine torque by creating pressure, which is acts like
a gear reduction, only it happens before power gets into the transmission.

Rotary Flow is achieved when the two blades are turning at a similar speed to one another. At this point
the stator's job is done, and is simply pushed along a one way clutch until a speed difference occurs
again. Rotary flow produces almost no torque multiplication because the engine and transmission are
turning at near the same speed, which would indicate cruising speeds or light throttle. The overall goal
of the torque converter is to achieve rotary flow, by using vortex flow to get there. Usually in each gear,
there is about 500rpm difference from when you let of the pedal, to full throttle. The RPM changes but
the gear does not. This is the torque converter attempting to make extra torque to get the turbine up to
the engine's current speed faster.

Vortex flow achieves additional torque by reapplying the turbine exhaust oil back into the impeller,
placing pressure on it, and multiplying the apply force, resulting in additional torque.
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 Rotary flow achieves a near 1:1 ratio, where speed is needed, and torque is not. Once the blades are of
similar speed, they can no longer produce torque since an object cannot turn faster with the same power
applied to it than the source that supplied it without physical gearing, and even if it could, it would be
counterproductive since the impeller would lose its apply force, similar to starving an engine bearing of
oil at high rpm.

What does a torque converter clutch do?

This is the mechanical link used when rotary flow is high, to provide a direct 1:1 ratio for the best
possible fuel mileage, without sacrificing acceleration and torque multiplication. Many people think
their automatic is a 5 speed, but in fact it is a 4 speed, with a converter clutch, which will feel like a 5th
gear shift when it locks. Simply pressing the gas or the brake will disengage it, and the rpm will jump
up/down around 200-400rpm depending on the engine. Looking at the picture above, the TCC solenoid
will apply oil pressure between the turbine and the TCC face, pressing the clutch onto the machine
surface in the apply housing. This locks the turbine to the converter housing making it turn at engine
speed. If you would like, you can think of it as slipping 4th gear in a manual transmission, and then
dumping the clutch, preventing any further slippage.

Now on to the actual transmission. The case of the transmission serves to house all the internals. But on
both inside and outside, there are numerous devices that may not look so friendly, and allow the
transmission to do its job without your every intervention. The oil pan, side pan, servo covers ,shaft
speed sensors, the PRNDL (Gear Position) switch, cooler lines, and a lot more.

Oil Pump: This provides lubrication and hydraulic oil flow for the circuits in the valve body, apply oil
for the clutches and bands in the transmission, and oil for the torque converter. This particular pump is a
variable displacement vane type pump. It has the ability to change its output based on load, by using a
pivoting housing that can be controlled by a throttle valve, boost valve, or a solenoid valve if its
electronically shifted. It is always driven by the engine. Some use a gerotor type design, similar to a
Honda oil pump.

Shaft Speed Sensors: Very similar to the speedometer sensor in design and function, these sensors are
used to determine if the incoming RPM and outgoing RPM are within a reasonable frame, to determine
if the transmission is operating normally. If a clutch slips, the sensors will detect this, and take

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 appropriate action. This can include placing the powertrain in limp-in mode to prevent damage,
disabling the affected component if it can, and producing a DTC to help diagnose the failure. Many of
these codes are OEM dependent, due to the proprietary design of the transmission, but there is a
standard code set for automatic transmissions.

Clutch Packs/Drums: These are used to drive members of a planetary gear set, and can be used in
conjunction with one way clutches to do this. The assembly consist of a drum, which is affixed to the
one end of the object to be driven, steel plates and clutches, and a piston in the back to force the clutches
into the steel plates, this engages a gear, or a planetary member, depending on design. The steel plates
spline to the drum, and the clutches spline to a shaft, or planetary member. If the outside of the drum is
precision machined, a band may also hold this member stationary for certain gears to make the assembly
much smaller.

Accumulators: This is a cushion device, and is round in shape and usually 1-3 inches in size. It's job is
to cushion the apply of a gearshift by allowing hydraulic pressure to push downward on it, so the clutch
applies smoothly. It resists the oil apply pressure with spring pressure on the opposing side of the piston.
The picture above shows the stock spring, and the replacement metal rod to make the clutch apply faster,
and harder. The TV valve or a solenoid valve assembly can feed oil to the backside of this piston,
opposing main line pressure, to help engage the gear faster during high load acceleration.

Valve Body: This is the complex PCM of the transmission. A series of hydraulic circuits that allow
hydraulic oil to apply many different devices. In many cases they should not be serviced, only replaced
as a unit. Aftermarket kits that replace the spool valves and springs and other components such as
accumulators to enhance performance are available. These can turn the traditional economy transmission
into a performance machine.

Solenoids: These can be on/off or duty cycle solenoids that can both be either normally open, or
normally closed, depending on if the pressure is normally exhausted, or normally applied. They can
apply clutches for gears, along with other comfort pressures. The PCM or TCM, if equipped, uses
engine sensors to determine the drivers demand, by using throttle angle, manifold pressure, and rpm.

Planetary gearing
When we take apart and look inside an automatic transmission, you find a huge assortment of parts in a
fairly small space. Among other things, you see:

• An ingenious planetary gearset

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 • A set of bands to lock parts of a gearset
• A set of three wet-plate clutches to lock other parts of the gearset
• An incredibly odd hydraulic system that controls the clutches and bands
• A large gear pump to move transmission fluid around

The center of attention is the planetary gearset. About the size of a cantaloupe, this one part creates all
of the different gear ratios that the transmission can produce. Everything else in the transmission is there
to help the planetary do its thing. This amazing piece of gearing has appeared on HowStuffWorks
before. You may recognize it from the electric screwdriver article. An automatic transmission contains
two complete planetary gearsets folded together into one component. See How Gear Ratios Work for an
introduction to planetary gearsets.

Any planetary gearset has three main components:

• The sun gears

• The planet gears and the planet gears' carrier
• The ring gears

Each of these three components can be the input, the output or can be held stationary. Choosing which
piece plays which role determines the gear ratio for the gearset. Let us take a look at a single planetary
gearset.

Figure 16: PLANETARY GEARSET

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 Now that the gear portion is done, it will be time to explain how it actually shifts gears automatically.
An automatic comes in two types, Hydraulically controlled shift, or Electronically controlled shift. In
either case, they shift gears in the same manner, but use a different device to control the transmission.
The following diagram is for demonstration purposes only, and is greatly simplified to show how a
valve body would function. Refer to the picture below:

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MACHINES & TOOLS USED DURING THE TRAINING PERIOD:
1. TORQUE RENCH
2. SPANNERS
3. SOCKETS
4. SCREW-DRIVERS
5. HAMMER
6. COMPRESSOR
7. INJECTOR CALIBRATION BENCH
8. DIAL GAGUE
9. COMPRESSOR
10. FILLET GAGUE
11. MICROMETER
12. VERNIER CALLIPER
13. CRANK HANDLE
14. T HANDLE
15. LUBRICANTS
16. LATHE MACHINE
17. MILLING MACHINE
18. GRINDING MACHINE
19. AIR COMPRESSOR
20. OVER HEAD CRANES
21. MOBILE CRANE

Bibliography
1. AUTOMOBILE ENGINEERING …… R B GUPTA
2. KIRPAL SINGH …………………………. VOL1., VOL2.
3. AUTOMOTIVE MECHANICS………. WILLIAM H CROUSE

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