204-L-2-E

2. ENGINE DISMOUNTING We have studied the working of an IC engine and also the working of the various systems of the engine, namely, the fuel system, the lubrication system, the cooling system and for petrol engines, the ignition system. All these systems together make an efficient working machine. But as the car becomes older, parts of the systems get worn out and the systems start malfunctioning, making it necessary to dismantle the engine, inspect the parts for wear and tear, repair or replace the parts and overhaul the engine.

In this lesson we will see how to dismantle various components connected to an engine before taking it out from the car. Removal of these components is necessary for easy removal of engine from the car. A few of these components are battery, bonnet, grille, wiring, bumper, lights, upper and lower member, radiator, carburetor connections, fuel pump connections, exhaust pipe, transmission connections, engine mountings etc.

2.0

Objectives

After going through this lesson, you will be able to: i. Recognize the different components connected to an engine. ii. Know the stepwise procedure of removing various components and connections from an engine. iii. Realize the need of removing the components connected to the engine. iv. Know the stepwise procedure of removal of engine and transmission from the vehicle

2.1

Introduction

Since the engine is the heart of the automobile, it is connected to the vehicle and its various sub-systems through some fasteners, connections, wiring etc. An engine is connected to the cooling system, ignition system, starting system, fuel system, exhaust system, transmission system, and the electrical system of a vehicle.

Therefore, to dismount an engine from a vehicle, many components and accessories have to be removed first so that the engine can be safely taken out without any damage to the coupled parts.

The engine is dismounted from the car by first disconnecting the various systems from the body or chassis of the car. It is a lengthy procedure and a definite sequence has to be followed. In this lesson, we shall study this procedure of dismantling the various systems of the car from the engine and the engine can then be dismounted by lifting it out from the car by using a chain pulley block or a jib crane. Due care must be taken while the engine is lifted out, as we have already seen in the lesson on service tools and equipment.

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Removal of Battery, Bonnet, Grille and Bumper Disconnect the negative and positive cable from the battery terminals.

Remove the battery clamp which is held by two nuts.

Remove the battery with insulation tray, and after that remove the battery bracket.

Loosen the hinge bolts on both sides and remove the engine hood which is also called the bonnet. Keep the bonnet carefully so that its paint is not scratched or damaged.

Remove the front grille, held with two screws, with the help of a Phillips type screw driver. Keep the grille aside and out of way.

Remove bonnet lock by removing the two bolts.

Remove the ground wire connected to the body on both sides.

Before removing the bumper, disconnect the couplers of parking lights as the parking lights are fixed in Fig. 2.1: Removal of bumper. the bumper. The bumper can be removed next.

Removal of Head Lights, Front, Upper and Lower Members Remove the head light unit on both sides after disconnecting the holder.

Remove the two bolts holding the radiator to upper member of bumper.

Loosen the bolts of the bumper upper member.

Remove the upper and lower members of the bumper.

Fig. 2.2: Removal of headlight.

Removal of Radiator Disconnect the radiator fan thermoswitch lead wire at the coupler.

Disconnect the radiator fan lead wire at the coupler.

Loosen the clip and disconnect the radiator outlet hose from the outlet Fig. 2.3: Removal of radiator. pipe at the lower end and drain out the cooling water.

Loosen the clip and disconnect the radiator inlet hose from the thermostat cap.

Remove the radiator assembly along with the electric fan and the reserve tank or coolant bottle from the body. Keep aside the radiator carefully so that its fins and fan are not damaged.

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Removal of Electrical and Transmission Connections Pull off ignition coil high tension cord from the distributor.

Disconnect the lead wire from distributor terminal.

Disconnect the lead wire and the positive (+) battery cord from the starter motor switch.

Fig. 2.4: Disconnection of battery cord Disconnect the negative (-) battery from transmission case. cord from transmission case.

Disconnect the clutch cable from the clutch release lever and transmission case, by loosening the No. 12 nut.

Disconnect the back light switch lead wire at the coupler.

Release the transmission breather hose from its clamp at the transmission case.

Disconnect the speedometer cable from the transmission case.

Disconnect the coupler and lead wire from the alternator terminals.

Removal of Carburetor Connections Open the No. 10 nut on air cleaner cap and a No. 10 bolt on cylinder head cover to remove the air cleaner case.

Remove the breather hose at the air cleaner end. This hose connects the cylinder head cover to the air cleaner.

Disconnect the choke wire from the Fig. 2.5: Air cleaner and breather hose. carburetor body.

Disconnect the accelerator wire from the carburetor body.

Disconnect the carburetor solenoid lead wire at the coupler.

Disconnect the fuel return hose from the carburetor body.

Removal of Connections at Fuel Pump and Transmission Disconnect the fuel pump inlet hose from the fuel pump.

Disconnect the lead wire from the water temperature gauge.

Disconnect the lead wire from the oil pressure switch.

Hoist the car.

Fig. 2.6: Hoisting the car.

Disconnect the exhaust centre pipe from the exhaust manifold.

Disconnect the gear shift control from the transmission case.

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Disconnect the extension rod from transmission case.

Remove the transmission drain plug using No. 10 Allen key and drain the transmission oil in a tray. Then screw in the drain plug.

Disconnect the left side drive shaft from differential side gear snap rings.

Similarly, disconnect the right side drive shaft.

Draw out the drive shafts, left and right, from the differential side gears.

Lower the car.

Remove the transmission left side mounting and mounting bracket.

Dismounting the Engine Remove the nuts securing the engine mounting on the front and rear to make the engine ready for removal.

Fig. 2.7: Engine mountings.

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Set a piece of wire across the hook on the inlet manifold and transmission case so that the engine can be lifted by using a chain pulley block. As the transmission case doesn’t have a hook, install a hook of the same type as the one on the intake manifold at the position on the transmission case.

Before finally lifting the engine, recheck to ascertain that all items are disconnected and free.

Lift the engine with the help of a chain pulley block.

Take down the engine with transmission and place it on the engine stand.

Remove the lifting hook and wires.

Fig. 2.8: (a) Chain pulley block. (b) Engine stand.

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Removal of Transmission System Loosen the bolts of the clutch housing.

Open the bolts holding the starter motor and remove the starter motor.

Loosen the clip of water inlet pipe and its holding bracket and remove the water inlet pipe.

Loosen and remove the nut holding the clutch cover and pull back the transmission.

Fig. 2.9: Starter motor.

The engine can now be mounted on the rotary stand for dismantling.

Self-check Questions 1. Before removing the bumper the couplers of the _____________ are to be disconnected as these are fixed in the bumper.

2. The radiator and the electric fan are removed separately one after the other.

State whether True/False.

3. List 5 items which are removed from the carburetor to free it from the car.

4. The drive shafts remain in the car even after the engine is dismounted. State whether True/False.

5. At how many points is the engine mounted? Name them.

6. A piece of wire is set across the hook on the _____________ and _______________ so that the engine can be lifted by using a ___________.

7. The _______________ does not have a hook and it has to be installed.

8. After the engine is removed from the car the ______________ is separated from it before the engine is mounted on the rotary stand.

2.10 Class Assignment 1. Review the order in which different components are dismantled from engine before taking it out from the car.

2. Review the procedure for removal of components of the fuel system.

3. Describe the procedure of engine dismounting.

2.11 Summing Up You studied the procedure of disconnecting the connections and removal of components of engine in this lesson and you would appreciate that the procedure is very methodical. The items have to be removed one after the other in a definite sequence in order that one item does not come in the way of another. Without removing these components it becomes practically impossible to dismount an engine from the car. So revise this lesson thoroughly before embarking on engine dismounting. Further, never be in a haste to lift off the engine from the car. First always make sure that all the disconnecting has been done.

2.12 Possible Answers to Self-check Questions 1. parking lights 2. False 3. air cleaner case, choke wire, accelerator wire, solenoid lead wire, fuel return hose.

4. True 5. 3 places; transmission left side mounting and mounting bracket, engine mounting at front and rear.

6. inlet manifold, transmission case, chain pulley block 7. transmission case 8. transmission

2.13 Terminal Questions 1. Considering that all the components and connections of an engine are removed, describe the procedure of dismounting an engine from the car.

2.14 References 1. Maruti 800 Service Manual

2.15 Glossary Chain pulley block

A type of lever to lift heavy objects like engine.

Coupler

A connector to make connections between two mating parts.

Disconnect

Removal of connection.

Dismantle

Convert into components; break into pieces.

Dismount

Take off or remove.

Rotary stand

A geared stand used to mount engine and turn to various positions while assembling or dismantling an aggregate.