cooling CHEVROLET CAMARO 1967 1.G Chassis Owner's Guide

ENGINE 6-20

Fig.
11 L
- J-21742 Centering Tool in Cover

tion from walking off the hub during installation

of damper.

2.

3.
Attach damper installer Tool J-22197 to damper.

Tighten fingers of tool to prevent weight from moving

(fig. 10L).

Position damper on crankshaft and drive into posi-

tion, using J-5590, until it bottoms against crankshaft

gear (fig. 10L). Remove installer tool.

4.
Install fan belt and adjust using strand tension gauge.

5.
If so equipped, install accessory drive pulley and

belt.

6. Install radiator core as outlined in Section 13.

7.
Fill cooling system and check for leaks.

CRANKCASE FRONT COVER

Fig.
121
- Installing Oil Seal (Cover Removed)
Fig. 13L- Installing Oil Seal (Cover installed)

Removal

1.
Remove oil pan as outlined.

2.
Remove crankshaft pulley and hub or torsional

damper as outlined.

3.
Remove crankcase front coyer attaching bolts, re-

move cover and gasket.

Installation

1.
Clean gasket surfaces on block and crankcase front

cover.

2.
Install centering Tool J-996 or Tool J-21742 in

crankcase front cover seal (fig. 11L).

3.
Coat the gasket with gasket sealer and place in posi-

tion on cover, then install crankcase front cover to

block and torque bolts to specifications.

4.
Remove centering tool.

NOTE: It is important that centering tool be

used to align crankcase front cover so that

crankshaft hub or torsional damper installation

will not damage seal and to position seal evenly

around the balancer or hub surface.

5.
Install crankshaft hub and/or torsional damper as

outlined.

6. Install oil pan with new gaskets and seals as outlined.

OIL SEAL (FRONT COVER)

Replacement

With Cover Removal

1.
With cover removed, pry old seal out of cover from

the front with screw driver being careful not to

distort cover.

2.
Install new seal so that open end of the seal is toward

the inside of cover and drive it into position with

ToolJ-995 (fig. 12L).

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-25

refer to Section 6 of the Chassis Overhaul Manual.

Because of the interchangeability and similarity of

many engines, engine sub-assemblies and engine parts,

regardless of which passenger vehicle they are used in,

typical illustrations and procedures are used except
where specific illustrations or procedures are necessary

to clarify the operation. Although illustrations showing

bench operations are used, most single operations, when

not part of a general overhaul, should be performed (if

practical) with the engine in the vehicle.

COMPONENT REPLACEMENT AND ADJUSTMENT

ENGINE ASSEMBLY

Removal

• .1. Drain cooling system and engine oil.

2.
Remove air cleaner and disconnect battery cables at

battery.

3.
Remove hood as outlined in Section 11.

4.
Remove radiator and shroud as outlined in Sec-

tion 13.

5. Remove fan blade and pulley as outlined in Sec-

tion 6K.

6. Disconnect wires at:

• Starter solenoid

• Delcotron

• Temperature switch

• Oil pressure switch

• Coil

7. Disconnect:

• Accelerator linkage at pedal lever.

• Exhaust pipes at manifold flanges.

• Vacuum line to power brake unit at manifold (if

so equipped),

• Power steering pump lines at pump end (if so

equipped).

• Fuel line (from tank) at fuel pump.

• Engine cooler lines (if so equipped).

• Oil pressure gauge line (if so equipped).

8. Raise vehicle and place on jack stands.

9. Remove propeller shaft.

NOTE:
If plug for propeller shaft opening

in transmission is not available, drain

transmission.

10.
Disconnect:

• Shift linkage at transmission.

• Speedometer cable at transmission.

• Transmission cooler lines (if so equipped).

11.
On synchromesh equipped vehicles, disconnect clutch

linkage at cross-shaft then remove cross-shaft en-

gine bracket.

12.
Remove rocker arm covers as outlined, then attach

engine lifting adapter at the proper cylinder head bolt

locations.

13.
Remove front mount bolts.

14.
Attach lifting device and raise engine to take weight

off front mounts, then remove rear mount bolts.

15.
Raise engine to take weight off rear mount, then re-

move crossmember.

NOTE:
On Chevrolets it will be necessary to

remove mount from transmission before cross-

member can be removed.

16.
Remove engine-transmission assembly from vehicle

as a unit.

17.
Remove transmission (and clutch):
Synchromesh Transmission

a. Remove clutch housing cover plate screws.

b.
Remove bolts attaching the clutch housing to en-

gine block then remove transmission and clutch

housing as a unit.

NOTE:
Support the transmission as the last

mounting bolt is removed, and as it is being

pulled away from the engine (to prevent damage

to clutch disc).

c. Remove starter and clutch housing rear cover

plate.

d. Loosen clutch mounting bolts a turn at a time (to

prevent distortion of clutch cover) until the spring

pressure is released. Remove all bolts, clutch

disc and pressure plate assembly.

Automatic
Transmission

a. Lower engine, secured by the hoist, and support

engine on blocks.

b.
Remove starter and converter housing underpan.

c. Remove flywheel-to-converter attaching bolts.

d. Support transmission on blocks.

e. Remove transmission-to-engine mounting bolts.

f. With the hoist attached, remove blocks from the

engine only and slowly guide the engine from the

transmission.

18.
Mount engine in stand.

Installation

1.
Attach lifting device to engine and remove engine

from engine stand.

2.
Install transmission (and clutch):

Synchromesh Transmission

a. Install the clutch on flywheel as outlined in Sec-

tion 7.

b.
Install clutch housing rear cover and starter.

c. Install transmission and clutch housing as out-

lined in Section 7.

d. Install clutch housing cover screws and tighten

securely.

Automatic
Transmissions

a. Position engine adjacent to the transmission and

align the converter with the flywheel.

b.
Bolt transmission to engine, then raise engine and

transmission assembly and install flywheel to

converter attaching bolts.

c. Install converter housing underpan and starter.

3.
Tilt and lower engine and transmission assembly into

the chassis as a unit, guiding engine to align front

mounts with frame supports.

4.
Install front mount bolts and torque to specifications.

5. Raise engine enough to install rear crossmember,

then install crossmember, install rear mount, lower

engine and torque rear mount to specifications.

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-30

c". Install the valve locks and release the compres-

sor tool making sure the locks seat properly in

the upper groove of the valve stem.

NOTE: Grease may be used to hold the locks

in place while releasing the compressor tool.

396 and 427
cu.
in.
Engines

a. Install new valve stem oil seal (coated with oil)

in position over valve guide.

b.
Set the valve spring and damper and valve cap in

place.

c. Compress the spring with Tool J-5892 and install

the valve locks, then release the compressor tool,

making sure the locks seat properly in the groove

of the valve stem.

NOTE: Grease may be used to hold the locks

in place while releasing the compressor tool.

7.
Install spark ,plug, using a new gasket, and torque to

specifications. -

8. Install and adjust valve mechanism as outlined.

CYLINDER HEAD ASSEMBLY

Removal

1.
Remove intake manifold as outlined.

2.
Remove exhaust manifolds as outlined.

3.
Remove valve mechanism as outlined.

4.
Drain cooling system (block).

5.
Remove cylinder head bolts, cylinder head and gas-

ket. Place cylinder head on two blocks of wood to

prevent damage.

Installation

CAUTION: The gasket surfaces on both the

head and the block must be clean of any foreign

ttter and free of nicks or heavy scratches.

Under bolt threads in the block and threads on

Pie cylinder head bolt must be cleaned. (Dirt

will affect bolt torqueT)

1.
On engines using a STEEL gasket, coat both sides of

a new gasket with a good sealer, spread the sealer

thin and even. One method of applying the sealer that

will assure the proper- coat is with the use of a paint

roller. Too much sealer may hold the beads of the

gasket away from the head or block.

CAUTION: Use no sealer on engines using a

composition STEEL ASBESTOS gasket.

2.
Place the gasket in position over the dowel pins with

the bead up.

3.
Carefully guide cylinder head into place over dowel

pins and gasket.

4.
Coat threads of cylinder head bolts with sealing

compound and install finger tight.

5.
Tighten cylinder head bolts a little at a time in the

sequence shown on the torque sequence chart until

the specified torque is reached.

6. Install the exhaust manifold as outlined.

7.
Install the intake manifold as outlined.

8. Install and adjust the valve mechanism as outlined.
OIL
PAN

Removal

Chevrolet
and Camaro

1.
Disconnect battery positive cable.

2.
Disconnect distributor cap from distributor (to pr-e-

vent breaking distributor cap when engine is raised).

3.
Drain radiator, then disconnect lower radiator hose

at water pump and remove oil dip stick and tube

(where necessary). '

4.
Remove fan blade.

5.
Raise vehicle then drain engine oil;

6. Remove through bolts from engine front mounts.

Disconnect and remove starter.

7.
On vehicles equipped with automatic transmissions,

remove converter housing underpan.

8. Disconnect steering rod at idler lever then swing

steering linkage 4pwn for oil pan clearance.

9. Rotate crankshaft untii timing mark on torsional

damper is at 6:00 o'clock position.

10.
Using a suitable jack, and a block of wood to prevent

damaging oil pan, raise engine "enough to insert 2" x

4"
wood blocks under engine mounts (fig. 8V), then

lower engine onto blocks.

NOTE: If 2" x 4" wood blocks are cut 5-1/2"

long they can be used on all Chevrolet engines.

The 5-1/2" length up for In-line engines and the

4"
side up for V8 engines.

11.
Remove oil pan and discard gaskets and seals.

NOTE: -On the 396 and 427 cu. in. engine, the

oil pan has three 1/4" x 20 attaching bolts at ,

crankcase front cover. One located at each

corner and one at lower center.

Chevelle

1.
Remove engine from vehicle as outlined.

2.
Lower engine onto jack stands, one at each front

Tnaount and one at transmission extension.

CAUTION: Leave engine lift attached to en-

gine.
Do not remove all weight of engine off

engine lifET

3.
Remove starter.

4.
On vehicles equipped with automatic transmission

remove converter housing underpan.

5.
Remove oil pan and discard gaskets and seals.

Fig.
8V - Engine Blocked for Pan Removal

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-33

Fig.
13V - Installing TorsionaI Damper (283, 327 and 350)

4.
Remove accessory drive pulley, then remove tor-

sional damper retaining bolt (if so equipped).

5. Install Tool J-6978 to torsional damper and turn

puller screw to remove damper from crankshaft

(fig. 12V).

6. Remove tool.

Installation

CAUTION: It is necessary to use installer tool

to prevent the inertia weight section from walk-

ing off the hub during installation of damper.

283, 327 and 350 cu. in. Engines

(Except 327-325 HP & 350 HP)

1.
Coat front cover seal contact area (on torsional

damper) with engine oil.

Fig.
14V - Installing Torsional Damper (396 and 427)
2.
Attach damper installer Tool J-22197 to damper.

Tighten fingers of tool to prevent weight from moving

(fig. 13V).

3.
Position damper on crankshaft and drive into position

until it bottoms against crankshaft sprocket (fig.

13V).
Remove installer tool.

4.
Install accessory drive pulley.

5. Install radiator and shroud as outlined in Section 13.

6. Install fan pulley and fan as outlined in Section 6K.

7. Install fan belt and adjust to specifications using

strand tension gauge.

8. Fill cooling system, start engine and check for leaks.

396 and 427
cu.
in.
Engines

1.
Coat front cover seal contact area (on damper) with

engine oil.

2.
Place damper in position over key on crankshaft.

3.
Using Tool J-21058 pull damper onto crankshaft

(fig. 14V).

NOTE:
If engine or radiator has not been re-

moved from the vehicle a 1/2"- 20 x 5" bolt and

a
1/2"-20
nut may be used in place of the bolt

and nut of Tool J-21058.

CAUTION: Install bolt in crankshaft with suffi-

cient thread engagement (min. 1/2").

4.
Remove tool from crankshaft.

5. Install damper retaining bolt and torque to specifica-

tions,
then install accessory drive pulley.

6. Install radiator and shroud as outlined in Section 13.

7. Install fan pulley and fan as outlined in Section 6K.

8. Install fan belt and adjust to specifications using

strand tension gauge.

9. On Corvettes, lower engine and install front mount

through-bolts.

10.
Fill cooling system, start engine and check for leaks.

327
cu.
in. (325 & 350 HP)
Engine

Install damper as outlined for 396 and 427 cu. in. en-

gines,
using a 7/16"-20 x 5" bolt and nut in place of the

bolt and nut furnished with J-21058.

CRANKCASE FRONT COVER

Removal

1.
Remove oil pan as outlined.

2.
Remove torsional damper as outlined.

3.
Remove water pump as outlined in Section 6K.

4.
Remove crankcase front cover attaching bolts and

remove front cover and gasket, then discard gasket

Installation

283, 327 and 350 cu. in.
Engine

1.
Make certain that cover mounting face and cylinder

block front face are clean and flat.

2.
Coat the oil seal with engine oil and using a new

cover gasket, coated with gasket sealer, install cover

and gasket over dowel pins and cylinder block.

3.
Install cover screws and torque bolts to

specifications.

4.
Install water pump as outlined in Section 6K.

5. Install torsional damper as outlined.

6. Install oil pan as outlined.

CHEVROLET CHASSIS SOVKZ MANUAL

SECTION 6K

ENGINE COOLING

INDEX

Page

General Description . . . 6K-1

Maintenance and Adjustments 6K-1

Coolant Level 6K-1

Coolant System Checks 6K-1

Periodic Maintenance 6K-2

Cleaning 6K-2

Reverse Flushing 6K-2

Radiator 6K-2
Page

Cylinder Block and Cylinder Head 6K-2

Hot Water Heater 6K-2

Fan Belt . 6K-2

Adjustment ....". 6K-2

Thermostat . 6K-2

Replacement 6K-2

Water Pump. . . . 6K-3

Removal 6K-3

Installation 6K-3

GENERAL DESCRIPTION

A pressure cooling system is provided for on all

models by a pressure type radiator cap (fig. 1). The

pressure type radiator cap used is designed to hold a

pressure above atmospheric pressure in the cooling

system. Excessive pressure is relieved by a valve within

the cap that opens to radiator overflow.

The water pump is a ball bearing, centrifugal vane

impeller type. It requires no care other than to make

certain the air vent at the top of the housing and the drain

holes in the bottom do not become plugged with dirt or

grease. Removal and installation of the water pump is

covered in this section. For overhaul procedures of the

water pump refer to Section 6K of the Passenger Chassis

Overhaul Manual.
For radiator, refer to Section 13 of this manual For

radiator shroud, refer to Section 11 of this manual.

Fig.
I—Pressure Radiator Cap

MAINTENANCE AND ADJUSTMENTS

Coolant Level

The radiator coolant level should only be checked when

the engine is cool, particularly on cars equipped with air

conditioning. If the radiator cap is removed from a hot

cooling system, serious personal injury may result

The cooling system fluid level should be maintained

one inch below the bottom of the filler neck of the radia-

tor when cooling system is cold, or at the bottom of the

filler neck when the system is warm. It is very impor-

tant that the correct fluid level be maintained. The seal-

ing ability of the radiator cap is affected when the cooling

level is too high.

All passenger car cooling systems are pressurized

with a pressure cap which permits safe engine operation

at cooling temperatures of
up
to 247°F.

When the radiator cap is removed or loosened, the

system pressure drops to atmospheric, and the heat

which had caused water temperature to be higher than

212°F, will be dissipated by conversion of water to

steam. Inasmuch as the steam may form in the engine

water passages, it will blow coolant out of the radiator

upper hose and top tank, necessitating coolant replace-

ment Engine operating temperatures higher than the

normal boiling point of water are in no way objectionable

so long as the coolant level is satisfactory when the

engine is cooL

Upon repeated coolant loss, the pressure radiator cap

and seat should be checked for sealing ability. Also, the
cooling system should be checked for loose hose con-

nections, defective hoses, gasket leaks, etc.

Coolant System Checks

1.
Test for restriction in the radiator, by warming the

engine up and then turning the engine off and feeling

the radiator. The radiator should be hot at the top

and warm at the bottom, with an even temperature

rise from bottom to top. Cold spots in the radiator

indicate clogged sections.

2.
Water pump operation may be checked by running the

engine while squeezing the upper radiator hose. A

pressure surge should be felt Check for a plugged

vent-hole in pump.

NOTE:
A defective head gasket may allow ex-

haust gases to leak into the cooling system.

This is particularly damaging to the cooling

system as the gases combine with the water to

form acids which are particularly harmful to

the radiator and engine.

3.
To check for exhaust leaks into the cooling system,

drain the system until the water level stands just

above the top of the cylinder head, then disconnect

the upper radiator hose and remove the thermostat

and fan belt. Start the engine and quickly accelerate

several times. At the same time note any appreci-

able water rise or the appearance of bubbles which

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE COOLING 6K-2

are indicative of exhaust gases leaking into the coolr

ing system.

Periodic Maintenance

Periodic service must be performed to the engine cool-

ing system to keep it in efficient operating condition.

These services should include a complete cleaning and

reverse flushing as well as a reconditioning service.

In the course of engine operation, rust and scale ac-

cumulate in the radiator and engine water jacket. The

accumulation of these deposits can be kept to a minimum

by the use of a good rust inhibitor but it should be

remembered that an inhibitor will not remove rust al-

ready present in the cooling system.

Two common causes of corrosion are: (1) air suction--

Air may be drawn into the system due to low liquid level

in the radiator, leaky water pump or loose hose con-

nections; (2) exhaust gas leakage—Exhaust gas may be

blown into the cooling system past the cylinder head

gasket or through cracks in the cylinder head and block.

Cleaning

A good cleaning solution should be used to loosen the

rust and scale before reverse flushing the cooling

system. There are a number of cleaning solutions avail-

able and the manufacturer's instructions with the particu-

lar cleaner being used should always be followed.

An excellent preparation to use for this purpose is GM

Cooling System Cleaner. The following directions for

cleaning the system applies only when this type cleaner

is-used.

1.
Drain the cooling system including the cylinder block

and then close both drain plugs.

2.
Remove thermostat and replace thermostat housing.

3.
Add the liquid portion (No. 1) of the cooling system

cleaner.

4.
Fill the cooling system with water to a level of about

3 inches below the top of the overflow pipe.

5. Cover the radiator and run the engine at moderate

speed until engine coolant temperature reaches 180

degrees.

6. Remove cover from radiator and continue to run the

engine for 20 minutes. Avoid boiling.

7. While the engine is still running, add the powder

portion (No. 2) of the cooling system cleaner and

continue to run the engine for 10 minutes.

8. At the end of this time, stop the engine, wait a few

minutes and then open the drain cocks or remove

pipe plugs. Also remove lower hose connection.

CAUTION: Be careful not to scald your hands.

NOTE:
Dirt and bugs may be cleaned out of

the radiator air passages by blowing out with air

pressure from the back of the core.

Reverse Flushing

Reverse flushing should always be accomplished after

the system is thoroughly cleaned as outlined above.

Flushing is. accomplished through the system in a direc-

tion opposite to the normal flow. This action causes the

water to get behind the corrosion deposits and force

them out.

Radiator

1.
Remove the upper and lower radiator hoses and re-

place the radiator cap,

2.
Attach a lead-away hose at the top of the radiator.
3.
Attach a new piece of hose to the radiator outlet

connection and insert the flushing gun in this hose.

4.
Connect the water hose of the flushing gun to a water

outlet and the air hose to an air line.

5. Turn on the water and when the radiator is full, turn

on the air in short blasts, allowing the radiator to

fill between blasts of air.

CAUTION: Apply air gradually as a clogged

radiator will stand only a limited pressure.

6. Continue this flushing until the water from the lead-

away hose runs clear.

Cylinder Block and Cylinder Head

1.
With the thermostat removed, attach a lead-away

hose to the water pump inlet and a length of new hose

to the water outlet connection at the top of the engine.

NOTE:
Disconnect the heater hose when re-

verse flushing engine.

2.
Insert the flushing gun in the new hose.

3.
Turn on the water and when the engine water jacket

is full, turn on the air in short blasts.

4.
Continue this flushing until the water from the lead-

away hose runs clear.

Hot Water Heater

1.
Remove water outlet hose from heater core pipe.

2.
Remove inlet hose from engine connection.

3.
Insert flushing gun and flush heater core. Care must

be taken when applying air pressure to prevent

damage to the core.

Fan Belt

Adjustment

1.
Loosen bolts at Delcotron slotted bracket.

2.
Pull Delcotron away from engine until desired ten-

sion reading is obtained with a strand tension gauge.

Refer to Section 6, "Engine Tune-Up".

3.
Tighten all Delcotron bolts securely.

Thermostat

The thermostat consists of a restriction valve actuated

by a thermostatic element. This is mounted in the hous-

ing at the cylinder head water outlet above the water

pump,
thermostats are designed to open and close at

predetermined temperatures and if not operating properly

should be removed and tested as follows.

Replacement

1.
Remove radiator to water outlet hose.

2.
Remove thermostat housing bolts and remove water

outlet and gasket from thermostat housing (fig. 2).

3.
Inspect thermostat valve to make sure it is in good

condition.

4.
Place thermostat in hot water 25° above the temper-

ature stamped on the thermostat valve.

5. Submerge the valve completely and agitate the water

thoroughly. Under this condition the valve should

open fully.

6. Remove the thermostat and place in water 10° below

temperature indicated on the valve.

7. With valve completely submerged and water agitated

thoroughly, the valve should close completely.

8. If thermostat checks satisfactorily, re-install, using

a new housing gasket.

9. Refill cooling system.

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE COOLING 6K-3

Fig.
2— Replacing Thermostat
Water Pump

Removal

1.
Drain radiator and break loose the fan pulley bolts.

2.
Disconnect heater hose, lower radiator hose and

by pass hose (as required) at water pump.

3.
Loosen Delcotron and remove fan belt then remove

fan bolts, fan and pulley.

4.
Remove pump to cylinder block bolts and remove

pump from engine.

NOTE:
On in line engines, pull the pump

straight out of the block first, to avoid damage

to impeller.

Installation

1.
Install pump assembly on cylinder block and tighten

bolts securely. Use on new pump to block gasket(s).

2.
Install pump pulley and fan on pump hub and tighten

bolts securely.

NOTE:
A guide stud (5/16"-24 x 1-1/2" bolt

with the head removed) installed in one hole of

the fan hub will aid in aligning hub, pulley and

fan.
Remove stud after starting the remaining

three bolts.

3.
Connect hoses and fill cooling system.

4.
Install fan belt and adjust as previously outlined.

5. Start engine and check for leaks.

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-ELECTRICAL 6Y-29

each capacitor (not illustrated). The capacitor is

shorted if both readings are zero.

6. Resistor Rl: The resistor is open if both readings

are infinite.

7. Resistor R2: Use an ohmmeter scale on which the

1800 ohm value is within, or nearly within, the

middle third of the scale. If both readings are infi-

nite, the resistor is open.

8. Resistor R3: Use an ohmmeter scale on which the

680 Ohm value is within, or nearly within, the middle

third of the scale. If both readings are infinite, the

resistor is open.

9. Resistor R4: Select an ohmmeter scale on which the

15000 ohm value is within, or nearly .within, the

middle third of the scale. If either reading is infi-

nite, the resistor is open. ~

10.
Resistor R5: Use the lowest range ohmmeter scale.

The resistor is open if either reading is infinite.

NOTE:
This resistor on some applications may

be located in the vehicle wiring harness, and not

on the panel board.

11.
Resistor R6: An ohmmeter scale on which the 150

ohm value is within or nearly within, the middle

third of the scale should be used. If both readings

are infinite, the resistor is open.

REASSEMBLY

During assembly, coat with silicone grease both sides

of the flat insulators used between the transistors and

heat sink, and also the heat sink on the side on which the

transistors are mounted. The silicone grease, which is

available commercially, conducts heat and thereby pro-

vides better cooling.'

IGNITION PULSE AMPLIFIER

R-5

C-3 Ju

MAGNETIC PULSE

DISTRIBUTOR
IGNITION SWITCH REPLACEMENT (Figs.
21
i to 23i)

CHEVROLET, CHEVY II AND CORVETTE

1.
Raise hood and disconnect battery ground cable from

battery.

2.
Remove lock cylinder by positioning switch in "off"

position and inserting wire in small hole in cylinder

face. Push in on wire to depress plunger and con-

tinue to turn key counter-clockwise until lock cylin-

der can be removed.

3.
Remove the metal ignition switch nut from the pas-

senger side of the dash using Tool J-7607 (Fig. 21i).

4.
Pull the ignition switch out from under the dash and

remove the wiring connectors.

5. To remove the "theft resistant" connector, the

switch must be out from under the dash as outlined

in Step 4. Using a screw driver unsnap the locking

tangs on the connector from their position on the

switch as shown in Figure 22i. Unplug the connector.

6. Snap the connector into place on a new ignition

switch.

7. Place the switch into position from behind the dash

and install the metal ignition switch nut.

8. Install the lock cylinder.

9. Install the battery cable to the battery and lower the

hood.

CHEVELLE

1.
Disconnect battery ground cable.

2.
Remove ash tray, retainer attaching screws and

retainer.

3.
Remove A/C distributor duct retaining screws and

duct.

Fig.
19i—Pulse Amplifier Internal Circuitry
Fig.
20i—Transistor Checking

CHEVROLET Oi

ELECTRICAL-BODY
AND
CHASSIS
12-26

•
Low oil
pressure

• High engine temperature

• Defective wiring
or
switch

connector from sender

in block above starter
on

and
at
left front
of
distributor
on V-8
Sending Unit Replacement

1.
Disconnect wiring harness

unit terminal (located

L-6 engines

engines).

2.
Remove sender unit using Tool J-21757
or 12
point

socket, replace with
new
unit
and
check operation.

GENERATOR INDICATOR

1.
Ignition
on,
Engine
not
Running
and
Telltale Light

Off.

• Indicator bulb burned out, replace bulb.

• Open circuit
or
loose connection
in the
telltale

light circuit.

2.
telltale Light Stays
on
after Engine
is
Started.
If indicator light does
not go out at
engine idle

speed, refer
to
Charging Systems under Engine

Electrical, Section
6Y.

TEMPERATURE (COOLING SYSTEM) INDICATOR

The temperature indicator circuit consists
of two re-

motely located units, indicator gauge
and
engine sender

unit.
The
indicator gauge, located
in the
instrument

panel, consists
of a
red light which will indicate
an
over-

heated engine condition.

Engine Sender Unit Replacement

1.
Drain engine cooling system
to a
level below unit.

2.
Remove sender unit (located
in the
inlet manifold

near water pump housing
on V-8
engines and
in the

cylinder head near
an
exhaust port
oh L-6
engines)

and replace with new unit.

3.
Refill cooling system
and
check operation
of
unit.

CHEVELLE INSTRUMENTS AND GAUGES

INDEX

Page

General Description
* *
i2-26

Service Operations
12-26

Instrument Panel
12-26

Instrument Cluster.
12-26

Fuel Gauge and/or Ammeter
12-27

Clock,
i 12-27

Speedometer
12-27
Page

Speedometer Cable
.
. 12-27

Temperature Gauge
12-29

Oil Pressure Gauge
12-29

Indicator Lights.
. 12-29

Oil Pressure Indicator
12-29

Generator Indicator
. . 12-29

• Temperature Indicator
12-29

GENERAL DESCRIPTION

The Chevelle instrument cluster assembly consists
of:

a speedometer;
a
fuel gauge;
a
generator,
an
engine
tem-

perature and an
oil
pressure indicator lamp, and includes

a clock
on
deluxe models.
On
super sport models,
am-

meter, coolant temperature
and oil
pressure gauges
re-

place
the
appropriate indicator lights. Except
for the

speedometer,
all of the
indicator lamps, instruments
and

gauges
of
these clusters may
be
serviced without remov-

ing
the
instrument cluster assembly from
the
vehicle.

In addition
to the
instrument indicator lamps,
a
brake

warning lamp
is
included
in the
cluster
as
standard

equipment.
The
indicator
is
connected
to the
parking
brake
and
brake pressure differential switches
and

serves
a
dual function.
It
lights when the parking brake

is applied
and
also when
the
brake pedal
is
applied,
if a

malfunction should occur
in the
brake system
due to a

loss
of
hydraulic pressure. Servicing
of the
hydraulic

pressure differential switch
is
covered
in
Section
5 of

this manual.

Regular maintenance
is not
required on the instrument

cjLuster
or its
components other than maintaining dean

and tight electrical connections, replacing defective parts

and keeping
the
speedometer cable properly lubricated.

SERVICE OPERATIONS

INSTRUMENT PANEL ASSEMBLY

INSTRUMENT CLUSTER (Figs.
41
thru
44)

Removal

1.
Disconnect battery ground cable.

2.
Remove steering coupling bolt and disconnect steer-

ing shaft from coupling.

3.
Loosen mast jacket lower clamp.

4.
Remove
air
conditioning center distributor duct
(if

so equipped).

5. Remove radio rear support bracket screw.

6. Remove mast jacket upper support clamp and retain-

ing bolts from lower support (refer
to
Section
9,

Steering).
CAUTION: Cover mast jacket
and
parl

brake handle with
a
suitable material
to
prevc

scratching.

7.
Disconnect speedometer cable
at
rear
of
cluster

housing
and
speed warning control knob
at
panel
(if

so equipped).

8. Remove instrument panel retaining screws (nine

upper and five lower).
.

9. Working under the console remove four lower retain-

ing screws from instrument cluster housing.

10.
Pull instrument panel assembly from console and
lay

forward on mast jacket.

11.
Disconnect wiring harness, cluster lamps and wiring

CHEVROLET CHASSIS SERVICE MANUAL

ELECTRICAL-BODY AND CHASSIS 12-29

Fig.
43b - Speed Warning Device

TEMPERATURE AND/OR OIL PRESSURE

GAUGE

1.
Disconnect battery ground cable.

2.
Remove ash tray and ash tray retainer.

3.
Disconnect A/C hose from the distributor duct.

4.
Disconnect wiring connectors and lamp bulbs from

rear of gauge.

5. Disconnect oil pressure pipe fitting from rear of oil

pressure gauge.

6. Remove (3) screws retaining gauge assembly to

cluster cover and disengage unit from cover.

7. Remove (4) retaining nuts and remove gauge from

template.

8. To install, reverse removal procedure.

INDICATOR LIGHT REPLACEMENT

To replace any indicator or cluster bulb, unsnap the

proper socket from rear of instrument cluster, remove

and replace bulb, and reinsert unit into rear of cluster

housing.
OIL PRESSURE INDICATOR

If the light does not come on when the ignition switch is

turned on, or if the light comes on and remains on after

the engine is started, one or more the following condi-

tions is indicated:

• Low oil pressure

• Defective wiring or switch

• High engine temperature

Switch Replacement

1.
Disconnect wiring harness connector from sender

unit terminal (located in block above starter on L-6

engines and at left front of distributor on V-8

engines).

2.
Remove sender unit using Tool J-21757, replace with

new unit, and check operation.

GENERATOR INDICATOR

Ignition on, Engine not Running and

Telltale Light Off

1.
Indicator bulb burned out, replace bulb.

2.
Open circuit or loose connection in the telltale light

circuit.

Telltale Light Stays on after Engine is Started

If indicator light does not go out at engine idle speed,

refer to' Charging Systems under Engine Electrical,

Section 6Y.

TEMPERATURE
(COOLING
SYSTEM)
INDICATOR

The temperature indicator circuit, consists of two re-

motely located units, indicator gauge and engine sender

unit. The indicator gauge on all models uses a single

red light to indicate an overheated engine condition.

Engine Sender Unit Replacement

1.
Drain engine cooling system to a level below unit.

2.
Remove sender unit (located in the inlet manifold

near water pump housing on V-8 engines and in the

cylinder head near an exhaust port on L-6 engines)

and replace with new unit.

3.
Refill cooling system and check operation of unit.

CHEVROLET CHASSIS SERVICE MANUAL