Challenger Terra Gator 3244 Chassis. Manual - part 21

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Engine Maintenance

ENGINE MAINTENANCE

ENGINE VALVE LASH INSPECT / 
ADJUST

The initial valve lash adjustment on new engines,

rebuilt engines, or remanufactured engines is

recommended at the first scheduled oil change. The

adjustment is necessary due to the initial wear of the

valve train components and to the seating of the valve

train components.

This maintenance is recommended by Caterpillar as

part of a lubrication and preventive maintenance

schedule in order to help provide maximum engine life.

NOTE: Only qualified service personnel should

perform this maintenance. Refer to the engine

Service Manual or your engine service center

for the complete valve lash adjustment

procedure.

NOTE: Operation of Caterpillar engines with improper

valve adjustment can reduce engine efficiency.

This reduced efficiency could result in

excessive fuel usage and/or shortened engine

component life.

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WARNING: Ensure that the engine can

not be started while this maintenance is

being performed. To help prevent

possible injury, do not use the starting

motor to turn the flywheel.

Hot engine components can cause burns.

Allow additional time for the engine to

cool before measuring/adjusting valve

lash clearance.

Ensure that the engine is stopped before measuring

the valve lash. To obtain an accurate measurement,

allow the valves to cool before this maintenance is

performed.

The following components should be inspected and

adjusted when the valves are inspected and adjusted.

•

Valve actuators

•

Injectors;

•

Compression brakes.

Refer to the engine service manual for more

information.

Engine Maintenance

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Valve Lash Check

An adjustment is not necessary if the measurement of

the valve lash is in the rang shown in table below

NOTE: TC Exhaust stroke is 360° from Compression

stroke.

NOTE: The no. 1 cylinder is at the front of the engine

(see picture below).

FIG. 1: Cylinder and valve location

a. Exhaust Valves;

b. Inlet Valves.

If the measurement is not within this range, an

adjustment is necessary. Refer to the chapter “Valve

Lash Adjustment” for the proper procedure.

Valve Lash Adjustment

Use the following procedure to adjust the valve lash.

1. Ensure that the No. 1 pistion is at the TDC (Top

Dead Center) position on the compression stroke;

NOTE: To get No. 1 pistion in top center position. Turn

engine in the direction it runs untill all valves

from pistion 1 are closed. Until TDC (Top Dead

Center) is reached.

When the No. 1 pistion is at TDC. Install the timing

bolt in the flywheel.

2. Adjust the valve lash according to the table above;

a. Lightly tap the rocker arm with a soft mallet.

This will ensure that the lifter roller seats

against the camshafts base circle;

b. Loosen the adjustment locknut;

Inlet Valves

Exhaust Valves

Valve Lash (stopped Engine)

0,38 ± 0,08 mm 

(0,015 ± 0,003 inch)

0,64 ± 0,08 mm 

(0,025 ± 0,003 inch)

TC Compression Stroke

1-2-4

1-3-5

TC Exhaust Stroke

3-5-6

2-4-6

Firing Order

1-5-3-6-2-4

FIG. 1

Q000060S

A

B

TC Exhaust Stroke

Inlet Valves

Exhaust Valves

Valve Lash

0.38 ± 0.08 mm 

(0.015 ± 0.003 inch)

0.64 ± 0.08 mm 

(0.025 ± 0.003 inch)

Cylinders

1-2-4

1-3-5

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Engine Maintenance

c. Place the appropriate feeler gauge between

rocker arm and the valve bridge. Then, turn the

adjustemnt screw in a clockwise direction.

Slide the feeler gauge between the rocker arm

and the valve bridge. Continue turning the

adjustment screw until a slight drag is felt on

the feeler gauge. Remove the feeler gauge;

d. Tighten the adjustment locknut to a torque of

30 ± 7 Nm (22 ± 5 lb ft). Do not allow the

adjustment screw to turn while you are

tightening the adjustment. Recheck the valve

lash after tightening the adjustment locknut.

3. Remove the timing bolt and turn the flywheel by

360° in the direction of engine rotation. This will put

the No. 6 piston at the top center position on the

compression stroke. Install the timing bolt in the

flywheel;

4. Adjust the valve lash according to table above;

a. Lightly tap the rocker arm with a soft mallet.

This will ensure that the lifter roller seats

against the camshaft’s base circle;

b. Loosen the adjustment locknut;

c. Place the appropriate feeler gauge between

rocker arm and the valve bridge. Then, turn the

adjustment screw in a clockwise direction.

Slide the feeler gauge between the rocker arm

and the valve bridge. Continue turning the

adjustment screw until a slight drag is felt on

the feeler gauge. Remove the feeler gauge;

d. Tighten the adjustment locknut to a torque of

30 ± 7 Nm (22 ± 5 lb ft). Do not allow the

adjustment screw to turn while you are

tightening the adjustment locknut. Recheck the

valve lash after tightening the adjustment

locknut.

5. Remove the timing bolt from the flywheel after all

adjustment to the valve lash has been made.

Reinstall the timing cover.

NOTE: The valve lash must be adjusted before

adjusting the compression brake, if equipped.

TC Exhaust Stroke

Inlet Valves

Exhaust Valves

Valve Lash

0,38 ± 0,08 mm 

(0,015 ± 0,003 inch)

0,64 ± 0,08 mm 

(0,025 ± 0,003 inch)

Cylinders

3-5-6

2-4-6

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Engine Maintenance

ENGINE REMOVAL AND INSTALLATION

To make access to the engine, remove the bonnet with

frame complete. Before remove the bonnet and frame

check the adjustment of the bonnet, frame and cooler.

During the installation of the bonnet and frame, adjust

the bonnet, frame and cooler the same as it where

before removal.

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WARNING: Hot engine components can

cause injury from burns. Before

performing maintenance on engine, allow

engine and components to cool.

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WARNING: Remove all air pressure from

tanks before disconnecting any air hoses.

Pressurized air can cause serious

personal injury.

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WARNING: Never open coolant system

when fluid is hot. Hot fluid can cause

serious personal injury.

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WARNING: Personal injury can result

from contact with refrigerant.

Contact with refrigerant can cause

frostbite. Keep face and hands away to

help prevent injury.

Protective goggles must always be worn

when refrigerant lines are opened even if

the gauges indicated the system is empty

of refrigerant.

Always use precaution when a fitting is

removed. Slowly loosen the fitting. If the

system is still under pressure, release it

slowly in a well ventilated area.

Do not smoke when servicing air

conditioners or wherever refrigerant gas

may be present.

Inhaling air conditioner refrigerant gas

through a lit cigarette or other smoking

method or inhaling fumes released from a

flame contacting air condition refrigerant

gas, can cause bodily harm of death.

Use a certified recovery and recycling cart

to properly remove the refrigerant from the

air conditioning system.

NOTE: Put identification marks on all hoses, hose

assemblies, wires, and tube assemblies for

installation purposes. Any engine openings

such as turbo charger, intake manifold ports

and coolant ports should be plugged or capped

while their respective tubes, hoses and any

other connections are removed. Plugging

prevents fluid loss and helps keep contaminants

from entering the system.

NOTE: Cleanliness is an important factor. Thoroughly

clean exterior of components prior to

disassembly to prevent dirt from entering

internal mechanisms. Precision components

can be damaged by contaminants or dirt.

Perform disassembly procedures on a clean

work surface. Keep components covered and

protected at all times.

NOTE: Care must be taken to ensure fluids are

contained during performance of inspection,

maintenance, testing, adjusting and repair of

the machine. Be prepared to collect the fluid

with suitable containers before opening any

compartment or disassembling any component

containing fluids.
Dispose of all fluids according to local

regulations and mandates.

NOTE: Only a certified technician with certified

equipment is allowed to service the air

conditioning system.

NOTE: Whenever the air conditioning system is

opened, replace the air conditioning Receiver /

Dryer. See air conditioning Receiver / Dryer

removal and installation section.