1967 CHEVROLET CAMARO light

ENGINE-ELECTRICAL 6Y-22

ADJUST DWELL

ANGLE SETTING OR

POINT OPENING

Fig.
lOi—Settihg Point Opening

To adjust the contact point opening:

1.
If necessary, align points (fig. 9i) by bending the

fixed contact support. Do not bend the breaker lever.

Do not attempt to align used points; replace them

where serious misalignment is observed. Use an

aligning tool if available.

2.
Turn or crank the distributor shaft until the breaker

arm rubbing block is on the high point of the cam

lobe.
This will provide maximum point opening.

3.
Loosen the contact support lock screw.

4.
Use a screw driver (fig. lOi) to move the point sup-

port to obtain a .019" opening for new points and a

.016"
opening for used points.

5.
Tighten the contact support lock screw and recheck

the point opening.

6. After checking and adjusting the contact point open-

ing to specifications, the cam angle or dwell should

be checked with a dwell angle meter if such equip-

ment is available (see Specifications for proper dwell

angle).
If the cam angle is less than the specified

minimum, check for defective or misaligned contact

points or worn distributor cam lobes. The variation

in cam angle readings between idle speed and 1750

engine rpm should not exceed 3°. Excessive varia-

tion in this speed range indicates wear- in the

distributor.

NOTE:
Cam angle readings taken at speeds

above 1750 engine rpm may prove unreliable

on some cam angle meters.

Eight Cylinder Engine Distributor

On the Vehicle

With the engine running at idle and operating tempera-

tures normalized, the dwell is adjusted by first raising

the window provided in the cap and inserting a "Hex"

type wrench into the adjusting screw head (fig. Hi).
WINDOW

r- "HEX" TYPE

WRENCH

ADJUSTING

SCREW

Fig.
-lli—Adjusting Dwell Angle

1.

Preferred Method - Turn the adjusting screw until

the specified dwell angle is obtained as measured in

degrees (28° to 32°, 30° preferred) by a dwell angle

meter.

2.
Alternate Method - Turn adjusting screw in (clock-

wise) until the engine begins to misfire, then turn

screw 1/2 turn in the opposite direction (counter-

clockwise). This will give the approximate dwell

angle required. (Use only when meter is not

available.)

Off the Vehicle

1.
Distributor Test Method:

a. With the distributor mounted on a distributor

testing machine, connect the dwell meter to the

distributor primary lead.

b.
Turn the adjusting screw (fig. lli) to set the dwell

angle to 30 degrees.

2.
Test Light Method:

a. With the distributor mounted in a vise, connect a

testing lamp to the primary lead.

b.
Rotate the shaft until one of the circuit breaker

cam lobes is under the center of the rubbing block

of the breaker lever.

c. Turn the adjusting screw clockwise (fig. lli) until

the lamp lights, then give the wrench 1/2 turn in

the opposite direction (counter-clockwise) to ob-

tain the proper dwell angle.

DISTRIBUTOR CONDENSER

PERFORMANCE DIAGNOSIS

The following four factors affect condenser perform-

ance,
and each factor must be considered in making any

condenser test.

1.
Breakdown - A failure of the insulating material. A

direct short between the metallic elements of the

condenser. This prevents any' condenser action.

2.
Low Insulating Resistance (Leakage) - Low insula-

tion resistance prevents the condenser from holding

a charge. All condensers are subject to leakage

which, up to a certain limit, is not objectionable.

3.
High Series Resistance - Excessive resistance in

the condenser circuit due to broken strands in the

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-ELECTRICAL 6Y-26

INSTALLATION-ENGINE NOT DISTURBED

(ALL MODELS)

1.
Turn the rotor about 1/8 turn in a clockwise direc-

tion past the mark previously placed on the distribu-

tor housing to locate rotor.

2.
Push the distributor down into position in the block

with the housing in a normal "installed" position

(fig. 15i).

NOTE: It may be necessary to move rotor

slightly to start gear into mesh with camshaft

gear, but rotor should line up with the mark

when distributor is down in place.

3.
Tighten the distributor clamp bolt snugly and con-

nect vacuum line. Connect primary wire to coil

terminal and install cap. Also install spark plug and

high tension wires if removed.

NOTE: It is important that the spark plug wires

be installed in their proper location in the

supports.

4.
Time ignition as previously described under Tune-

Up in Section 6.

INSTALLATION-ENGINE DISTURBED

(ALL MODELS)

1.
Locate No. 1 piston in firing position by either of two

methods described below,

a. Remove No. 1 spark plug and, with finger on plug

hole,
crank engine until compression is felt in the

No.
1 cylinder. Continue cranking until timing

mark on crankshaft pulley lines up with timing

tab attached to engine front cover.

b.
Remove rocker cover (left bank on V-8 engines)

and crank engine until No. 1 intake valve closes

and continue to crank slowly about 1/3 turn until
CENTRIFUGAL

jS ADVANCE

ROTATING

POLE PIECE

STATIONARY

POLE PIECE

MAGNETIC

PICKUP

ASSEMBLY

VACUUM

ADVANCE

DISTRIBUTOR

HOUSING

Fig.
151—Six Cylinder Engine Distributor
Fig.
16i—Magnetic Pulse Distributor Components

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-ELECTRICAL 6Y-27

timing mark on pulley lines up with timing tab.

2.
Position distributor to opening in block in normal

installed attitude (fig. 15i), noting position of vacuum

control unit.

3.
Position rotor to point toward front of engine (with

distributor housing held in installed attitude), then

turn rotor counter-clockwise approximately 1/8 turn

more toward left cylinder bank and push distributor

down to engine camshaft. It may be necessary to ro-

tate rotor slightly until camshaft engagement is felt.

4.
While pressing firmly down on distributor housing,

kick starter over a few times to make sure oil pump

shaft is engaged. Install hold-down clamp and bolt

and snug up bolt.

5. Turn distributor body slightly until points just open

and tighten distributor clamp bolt.

6. Place distributor cap in position and check to see

that rotor lines up with terminal for No. 1 spark

plug.

7. Install cap, check all high tension wire connections

and connect spark plug wires if they have been re-

moved. It is important that the wires be installed in

their location in the supports.

NOTE:
The brackets are numbered to show the

correct installation. Wires must be installed as

indicated to prevent cross firing.

8. Connect vacuum line to distributor and distributor

primary wire to coil terminal.

9. Start engine and set timing as described under Turn-

Up in Section 6.

BREAKERLESS (MAGNETIC PULSE)

DISTRIBUTOR

REMOVAL (CORVETTE)

1.
If vehicle is equipped with radio, remove three bolts

securing ignition shield over distributor and coil.

One bolt is accessible from the top of shield, the

other two are at rear of shield, facing firewall.

2.
Disconnect tachometer drive cables from distributor

housing.

3.
Disconnect pickup coil leads at connector.

4.
Remove distributor cap.

5. Crank engine so rotor is in position to fire No. 1

cylinder and timing mark on harmonic balancer is

indexed with pointer.

6. Remove vacuum line from distributor.

7. Remove distributor clamping screw and hold-down

clamp.

8. Remove distributor and distributor-to-block gasket.

It will be noted that the rotor will rotate as the

distributor is pulled out of the block. Mark the re-

lationship of the rotor and the distributor housing

after removal so that the rotor can be set in the

same position when the distributor is being installed.

DISASSEMBLY (Fig. 16i)

NOTE:
If a distributor is being disassembled

for replacement of the stationary magnetic

pickup assembly only, it will be necessary to

perform only Steps 3, 4, 5, 7, 8, 9, and 12 of the

service procedure listed below.
1.
Remove screws securing rotor and remove rotor.

2.
Remove centrifugal weight springs and weights.

3.
Remove the tachometer drive gear from the distribu-

tor (Corvette only).

4.
Remove roll pin, then remove distributor drive gear

and washer.

CAUTION: To prevent

magnet, support drive gear
;e to the permanent

?n
driving out roll

pin.

5. Remove drive shaft assembly.

6. Remove centrifugal weight support and timer core

from drive shaft.

7. Remove connector from pickup coil leads.

8. Remove retaining ring which secures magnetic

core support plate to distributor shaft bushing in

housing.

9. As a unit, remove the entire magnetic pickup assem-

bly from the distributor housing.

10.
Remove brass washer and felt pad.

11.
Remove vacuum advance unit.

12.
To reassemble distributor, perform the above steps

in reverse order.

INSTALLATION (CORVETTE)

1.
Check to see that the engine is at firing position for

No.
1 cylinder (timing mark on harmonic balancer

indexed with pointer).

2.
Position a new distributor-to-block gasket on the

block.

3.
Before installing distributor, index rotor with hous-

ing as noted when distributor was removed. Install

distributor in block so that vacuum diaphragm faces

approximately 45° forward on the right side of the

engine and the rotor points toward contact in cap for

No.
1 cylinder.

4.
Replace distributor clamp leaving screw loose

enough to allow distributor to be turned for timing

adjustment.

5. Install spark plug wires in distributor cap. Place

wire for No. 1 cylinder in tower (marked on old cap

during disassembly) then install remaining wires

clockwise around the cap according to the firing

order (1-8-4-3-6-5-7-2).

6. Attach distributor to coil primary wires.

7. Replace distributor cap.

8. Adjust timing and then fully tighten distributor clamp

screw.

9. Attach vacuum line to distributor.

10.
Connect tachometer drive cables to distributor body.

11.
Replace ignition shields.

DISTRIBUTOR OFF-ENGINE TEST

The distributor's centrifugal and vacuum advance can

be checked in a distributor testing machine or synchro-

scope specially adapted or designed to accommodate this

type distributor. However, since this involves removing

the distributor from the engine, this test may be post-

poned until other system checks have been made. A dwell

reading cannot be obtained on this distributor and it is not

likely that the centrifugal or vacuum advance will be a

cause of trouble.

COIL REPLACEMENT

1.
Disconnect ignition switch and distributor leads from

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-ELECTRICAL 6Y-33

O

V-8 ENGINE
STARTING MOTOR

Fig.
2s—V-8 Starting Circuit Diagram

2.

3.
From battery negative post
To
starting motor

housing.

From solenoid battery terminal
To
solenoid motor

terminal.

If voltage drop
in
any
of
above check exceeds 0.2 volts,

excessive resistance
is
indicated in that portion
of
start-

ing circuit
and the
cause
of the
excessive resistance

should
be
located
and
corrected
in
order to obtain maxi-

mum efficiency in the circuit.

CAUTION:
Do not
operate
the
starting motor

continuously
for
more than
30
seconds
to
avoid

overheating.

When
the
solenoid fails
to
pull
in, the
trouble may be

due
to
excessive voltage drop in the solenoid control cir-

cuit.
To
check
for
this condition, close
the
starting

switch
and
measure
the
voltage drop between
the
BAT-

TERY terminal of the solenoid and the
SWITCH (S)
termi-

nal
of
the solenoid.
1.
If
this voltage drop exceeds 3.5 volts, excessive
re-

sistance
in the
solenoid control circuit
is
indicated

and should be corrected.

2.
If the
voltage drop does not exceed 3.5 volts and the

solenoid does not pull in, measure the voltage availa-

ble
at
the SWITCH terminal
of
the solenoid.

3.
If the
solenoid does
not
feel warm,
it
should pull
in

whenever the voltage available
at
the SWITCH termi-

nal
is 7.7
volts
or
more. When
the
solenoid feels

warm,
it
will require
a
somewhat higher voltage
to

pull in.

STARTING MOTOR AND SOLENOID CHECK

The following checks
may be
made
if the
specific

gravity of the battery
is
1.215
or
higher.

1.
If the
solenoid does
not
pull in, measure the voltage

between
the
switch
(S)
terminal
of the
solenoid
and

ground with the starting switch closed.

CAUTION:
If the
solenoid feels warm, allow
to

cool before checking.

If
the
voltage
is
less than 7.7 volts, check for ex-

cessive resistance
in the
solenoid control circuit.

If
the
voltage exceeds 7.7 volts, remove the starting

motor
and
check
(1)
solenoid current draw,
(2)

starting motor pinion clearance,
and (3)
freedom of

shift lever linkage.

2.
If
the solenoid "chatters" but does not hold in, check

the solenoid
for an
open "hold-in" 'winding. When-

ever
it is
necessary
to
replace
a
starting motor

solenoid, always check starting motor pinion

clearance.

3.
If
motor engages
but
does
not
crank
or
cranks

slowly, check
for
excessive resistance
in the ex-

ternal starting circuit, trouble within
the
starting

motor,
or
excessive engine resistance
to
cranking.

SERVICE OPERATIONS

STARTING MOTOR

REMOVAL AND INSTALLATION (Fig.
3s)

The following procedure
is a
general guide
for all

vehicles
and
will vary slightly depending
on
series
and

model.

1.
Disconnect battery ground cable at battery.

2.
Raise vehicle
to a
good working height.

3.
Disconnect all wires
at
solenoid terminals.

NOTE: Reinstall
the
nuts
as
each wire
is
dis-

connected
as
thread size
is
different but may be

mixed and stripped.

4.
Loosen starter front bracket (nut on V-8 and bolt on

L-6) then remove two mount bolts.

5.
Remove
the
front bracket bolt
or nut and
rotate

bracket clear
of
work area then lower starter from

vehicle
by
lowering front end first
—
(hold starter

against bell housing
and
sort
of
roll end-over-end).

6. Reverse
the
removal procedure
to
install. Torque

the mount bolts
to
25-35
ft.
lbs. first, then torque

brace bolt.

7.
Check operation
of
starter on vehicle.
Fig.
3s—Starter Mounting

CHEVROLET CHASSIS SERVICE MANUAL

CLUTCH AND TRANSMISSIONS 7-2

Fig.
2 - Chevelle Clutch Pedal Free Travel Adjustment (V-8 Shown)

some clearance between cross shaft and both its

mounting brackets.

CLUTCH LINKAGE ADJUSTMENT

There is one linkage adjustment (clutch fork push rod

or pedal push rod) to compensate for all normal clutch

wear.

The clutch pedal should have
1-1/4"
free travel (meas-

ured at clutch pedal pad) before the throwout bearing en-

gages the clutch diaphragm spring levers. Lash is re-

quired to prevent clutch slippage which would occur if the

bearing was held against the fingers and to prevent the

bearing from running continually until failure.

Chevrolet Linkage Adjustment (Fig. 1}

With Nuts (A) & (B) loose on Rod (D)
&
before installa-

tion of Clutch Pedal Return Spring
(E),
apply approximately

5 lbs. load in direction of arrow (F) to eliminate clear-

ance between throwout bearing and clutch fingers. Move

Rod (D) in direction of arrow (G) until Clutch Pedal Arm

makes contact with Bumper Stop on instrument panel

brace. Run Nut (B) toward Swivel until dimension (X) is

9/32". Tighten Nut (A) to lock Swivel (C) against Nut (B).

Install Clutch Pedal Return Spring (E).

The foregoing procedure will provide a free pedal

travel of 1" to
1-1/2"
measured on a perpendicular from

the crown of the, pedal pad to the bare metal toe pan.

Chevelle Linkage Adjustment (Fig. 2)

1.
Disconnect spring between cross shaft lever and

clutch fork.

2.
Loosen push rod locknut about three turns.

3.
If there is no free travel, shorten the rod (by turning

at square wrench area) until it is free of clutch fork.

4.
Hold the clutch fork rearward to move throwout

lightly against clutch release fingers, then adjust rod

length until rod just touches ,its seat in the fork.
5.
Adjust locknut to obtain approximately 3/16" clear-

ance between nut and rod sleeve end.

6. Turn the rod with wrench, until the nut just comes in

contact with rod sleeve end, then hold the rod with

wrench and tighten locknut.

7.
Check free pedal travel at pedal (1" to
1-1/2"
is

proper clearance). Readjust if necessary.

Chevy II Linkage Adjustment (Fig. 3}

L-4 & L-6 Models

1.
Loosen locknut "A" and lengthen or shorten push rod

in swivel as required by turning with wrench on ma-

chined flat "B". (Shorten push rod to increase pedal

lash).

2.
Hold push rod at flat "B" and tighten locknut "A".

3.
Recheck pedal free travel.

NOTE: A measurement of approximately 3/16"

between push rod and its seat in fork will give

required pedal free travel.

V-8 Models

The eight cylinder linkage has a two-piece clutch fork

push rod (fig. 3). Adjust clutch pedal free travel by turn-

ing the adjusting rod portion of the push rod to obtain apr

proximately 3/16" clearance between clutch fork and end

of rod, ttien tighten locknut to 8-12 lbs. ft. and check free

travel at pedal. Pedal free travel on all models should

be 1" to
1-1/2".

Corvette Linkage Adjustment

Refer to fig. 1 and the following procedure:

1.
Disconnect pedal return spring.

2.
With Nuts (A) and (B) loose on Rod (D) apply push

hard load in direction of arrow (F) to eliminate

clearance between throwout bearing and clutch

fingers.

3.
Run Nut (B) towards Swivel (C) until dimension (X)

is 3/8" to 7/16".

4.
Tighten Nut (A) to lock swivel against Nut (B).

5.
Connect pedal return spring and check pedal free

travel for
1-1/4"
minimum to 2" maximum.

6. Check every 3,000 miles.

7.
Adjust free travel to 2" to 2-1/2" for heavy duty op-

eration. The return spring may be removed for

heavy duty conditions.

Camaro Linkage Adjustment

Refer to Figure 4 and the following procedure:

Apply a 10 lb. load in direction of Arrow (E) to hold

Clutch Pedal against Clutch Pedal Bumper.

Apply a 10 lb. load to Clutch Fork in direction of Arrow

(D) to eliminate clearance between throwout bearing and

clutch fingers.

Insert a .198 Spacer (F) between clutch fork and Ad-

justing Rod (A).

Rotate Adjusting Rod against Spacer until it has a 5 in.

lb.
torque.

Hold Adjusting Rod and tighten Nut (C) against Swivel

(B) or Rod (B).

Remove Spacer. Install return spring and extension to

clutch fork.

Pedal will have approximately 1" to
1-1/8"
free travel.

A clutch that has been slipping prior to free play ad-

justment may still slip right after the new adjustment due

CHEVROLET CHASSIS SERVICE MANUAL

CLUTCH AND TRANSMISSIONS 7-4

5.
Install Tool J-5824 to support the clutch assembly

during removal.

NOTE: Look for "X" mark on flywheel and on

clutch cover. If MX" mark is not evident, prick

punch marks on flywheel and clutch cover for

indexing purposes during installation.

6. Loosen the clutch-to-flywheel attaching bolts evenly

1 turn at a time until spring pressure is released,

then remove the bolts, and remove clutch assembly.

Installation to Vehicle

Clean pressure plate and flywheel face. (They should

be free of oil, grease, metal deposits or burned spots).

1.
Position the clutch disc and pressure plate in relar

tive installed position and support them with align-

ment Tool J-5824.

NOTE: The driven disc on the 4 and 6 cylinder

engines is installed with the damfper springs to

the flywheel side; the V-8 is opposite, however,

THE GREASE SLINGER IS ALWAYS ON THE

TRANSMISSION SIDE.

2.
Turn clutch assembly until "X" mark on cover lines

up with "X" mark oh flywheel, then align cover bolt

holes to nearest flywheel holes.

3.
Install a bolt in every hole and tighten down evenly

and gradually until tight (to avoid possible clutch

distortion).

NOTE: Cover loads are as high as 1-1/4 tons.

4.
Remove pilot tool.

5.
Unhook clutch fork and lubricate ball socket and fork

fingers at release bearing end with a high melting

point grease such as graphite and reinstall fork on

ball stud. On Corvette models use Moly Grease.

6. Lubricate the recess on the inside of throwout bear-

ing collar and the throwout fork groove with a light

coat of graphite grease (fig. 4). On Corvette models

use Moly Grease.

7.
Install clutch fork and dust boot into clutch housing

and install throwout bearing to the throwout fork, then

install flywheel housing.

8. Install transmission as outlined in transmission

section.

9. Connect fork push rod and spring.

10.
Adjust shift linkage as outlined in transmission

section.

11.
Perform linkage adjustment for pedal free play and

check clutch release position.

CLUTCH PEDAL

The clutch pedal is the pendant-type hung from a sup-
Fig. 5 - Release Bearing Lubrication and Comparison

port brace common to the brake pedal and must be re-

moved to remove brake pedal. Refer to Section 5 for

brake and clutch pedal service procedure.

CLUTCH CROSS SHAFT (Figs. 6, 7 & 8)

Removal

1.
Remove linkage return and lower linkage springs and

disconnect clutch pedal and fork push rods from re-

spective cross shaft levers.

2.
Loosen outboard ball stud nut and slide stud out of

bracket slot.

3.
Move cross shaft outboard, and as required to clear

inboard ball stud, then merely lift out to remove

from vehicle.

Repairs

The cross shaft has nylon ball stud seats which should

be inspected for wear or damage. Also check condition

of engine bracket ball stud assembly and special anti-

rattle "O" ring. Figures 6, .7
&
8 show component parts

of cross shaft. Replace parts as necessary based on wear

or damage. Lubricate ball studs and seats with graphite

grease before reassembly.

Installation

1.
Reverse removal procedure to install.

2.
Adjust clutch linkage as previously outlined.

CHEVROLET CHASSIS SERVICE MANUAL

CLUTCH AND TRANSMISSIONS 7-11

UPPER ARMATURE STOP

(BEND TO ADJUST POINT OPENING)

Fig.
2B-Adjusting Relay Point Opening

ELECTRICAL UNIT CHECKS

Overdrive Relay

Specifications and checking procedures for this relay

are as follows:

Specifications

Air Gap Oil inch minimum

Point Opening .025 inch

Closing Voltage
8.3-10.2
volts

Armature Sealing Voltage. ..... 11.2 volts maximum

Three checks and adjustments are required on the

overdrive relay; air gap, point opening and closing volt-

age.
The air gap contact point opening checks and adjust-

ments should be made with the battery disconnected.

Air Gap

The air gap should not normally require adjustment

unless the relay has been misadjusted. Check the air gap

with the points barely touching and adjust if necessary by

bending the lower point support (fig, IB).

Point Opening

Check the contact point opening and adjust by bending

the upper armature stop (fig. 2B).

Closing Voltage

To check the relay closing voltage, connect a potenti-

ometer or variable resistance of sufficient value (not less

than 50 ohms) in series with the "KD" terminal, connect a

voltmeter to the "IGN" and "KD" terminals. With the

ignition switch on, slowly decrease the amount of resist-

ance in order to check the relay closing voltage (the

overdrive solenoid and relay should click when the relay

closes). Adjust the closing voltage by bending the arma-

ture spring post (fig. 3B). Bend down to increase the

closing voltage and bend up to decrease the closing

voltage.

To check the sealing voltage, increase the voltage after

the relay closes until the armature seals against the

core.
Decrease the sealing voltage by reducing the relay

air gap.

Solenoid

Closing Coil

Remove solenoid from transmission, connect a jumper

wire between negative terminal of battery and mounting

flange of solenoid. Connect a second jumper wire be-
ARMATURE SPRING PQST

(BEND TO ADJUST CLOSING VOLTAGE)

Fig.
3B - Adjusting Relay Closing Voltage

tween the battery positive terminal and solenoid terminal

No.
4; this should cause the solenoid pawl to move out.

If solenoid chatters, Hold-In Coil is defective.

Engaging Spring

With jumper wire connected as in paragraph above,

(solenoid energized, plunger extended) place ball end of

solenoid against bench. Push down on solenoid. The

pawl rod should move in 3/8M under a load of not less

than 8 lbs. nor more than 12. Pawl should move out to

extended position when load is removed.

Ignition Grounding Contact

Place a test lamp between negative battery terminal

and solenoid terminal No. 6. Lamp should light when this

connection is made. Remove jumper from between nega-

tive battery terminal and solenoid terminal No. 4. Pawl

rod should snap "in" and test lamp should go out.

Governor Switch

Remove overdrive wire at governor and connect test

lamp between governor overdrive terminal and positive

terminal of battery. Drive car on road or raise on jacks.

The lamp should light at a car speed of between 26 to 30

MPH. Upon decreasing speed, the lamp should go out at

between 28 and 23.5 MPH. The car speed differential

between light "on" and light "off" should be 2 or 3 MPH.

Kickdown Switch

Disconnect the 4 wires at kickdown switch.

1.
Connect test lamp between "SW" terminal and posi-

tive terminal of battery; with switch in normal posi-

tion, lamp should light when "REL" terminal is

grounded but should not light when "IGN" or "SOL"

terminals or switch case is grounded.

2.
Connect test lamp between "IGN" terminal and posi-

tive terminal of battery; with switch stem pushed in,

lamp should light when "SOL" terminal is grounded,

but should not light when "SW" or "REL" terminals

or switch case is grounded.

CHEVROLET CHASSIS SERVICE MANUAL

CLUTCH AND TRANSMISSIONS 7-12

DIAGNOSIS-OVERDRIVE

MECHANICAL

Any one of the following general complaints may be due

to non-standard mechanical conditions in the overdrive

unit:

1.
Does not drive unless locked up manually.

2.
Does not engage, or lock-up does not release.

3.
Engages with a severe jolt, or noise.

4.
Free-wheels at speeds over 30 mph.

These^ troubles may be diagnosed and remedied as de-

scribed in the following paragraphs.

1.
Does not drive unless locked up manually.

a. Occasionally, the unit may not drive the car for-

ward in direct drive, unless locked up by pulling

the dash control. This may be caused by one or

more broken rollers in the roller clutch, the

remedy for which is the replacement of the entire

set of rollers.

b.
This may also be caused by sticking of the roller

retainer upon the cam. This retainer must move

freely to push the rollers into engaging position,

under the pressure of the two actuating springs.

c. Sometimes this is due to slight indentations, worn

in the cam faces by the rollers spinning, remedied

by replacement of the cam.

2.
Does not engage, or lock-up does not release

.. a. Dash control improperly connected—-Unless the

overdrive dash control wire is connected to the

lockup lever on the left side of the overdrive

housing in such a manner as to move the lever

all the way back when the dash control knob is

pushed in, it may hold the shift rail in such a po-

sition as to interlock the pawl against full engage-

ment resulting in a buzzing noise when overdrive

engagement is attempted.

To correctly make this connection, loosen bind-

ing post at lever, pull dash control knob out 1/4",

move lever all the way to the rear, and tighten

binding post.

b.
Transmission and overdrive improperly aligned—

The same symptoms as above may also result

from misalignment, at assembly, of the overdrive

housing to the transmission case, resulting in

binding of the overdrive shift rail, so that the re-

tractor spring cannot move the rail fully forward,

when the dash control knob is pushed in, and the

transmission is not in reverse. Under such con-

ditions, the unit may remain fully locked up.

To test for this, be sure that the transmission

is not in reverse; disconnect the dash control

wire from the lockup lever, and feel the lever for

free forward movement. If the lever can be

moved forward more than 1/4", it indicates that

misalignment probably exists. To correct this,

Jposen the capscrews between the overdrive hous-

ing and transmission case, and tap the adpater

plate and overdrive housing until a position is

found where the rail shifts freely; tighten cap-

screws.

c. Kickdown switch improperly adjusted—The posi-

tion of the kickdown switch should be adjusted,

by means of the two large nuts which clamp the

switch shank, so the switch plunger travels 3/16"
before the throttle lever touches its stop.

Occasionally the large nuts which clamp the

switch through the switch bracket are tightened

sufficiently to bend the switch shank, thus pre-

venting free motion of the switch stem. This may

usually be remedied by loosening the upper of the

two nuts.

d. Improper installation of solenoid—If car cannot

be rolled backward under any circumstances and

there is no relay click when the ignition is turned

on, it probably indicates that the solenoid has

been installed directly, without twisting into the

bayonet lock between solenoid stem and pawl, thus

jamming the pawl permanently into overdrive en-

gagement. If the car will occasionally roll back-

wards, but not always, (and there is no relay click

when the ignition switch is turned on) it may indi-

cate that, upon installation, the bayonet lock was

caught, and the solenoid forcibly twisted into

alignment with the attaching flange, thus shearing

off the internal keying of the solenoid. Under

these circumstances, the end of the solenoid stem

may not catch in the pawl, and upon release of the

solenoid, the pawl will not be withdrawn promptly

from engagement, but simply drift out. If the

solenoid stem end has its two flats exactly facing

the two solenoid flange holes, it will not withdraw

the pawl properly. If the stem can be rotated

when grasped by a pair of pliers, it indicates that

the internal keying has been sheared.

e. Improper positioning of blocker ring—Occasion-

ally, either in assembly at the factory, or in

service operations in the field, the internal parts

of the overdrive unit may have been rotated with

the solenoid pawl removed, causing the blocker

ring to rotate, so that its two lugs are not located

with respect to- the pawl as shown in Figure 12B.

In other words, the solid portion of the blocker

ring may be in alignment with the pawl, which will

prevent fill} engagement of the pawl with the sun

gear control plate/

To test for this condition, remove solenoid

cover, pull dash control knob out, roll car 2 ft.

forward. Push dash control in, turn ignition

switch on. Then ground the "KD" terminal of

relay, and watch movement of center stem of

solenoid. It should not move more than 1/8" when

the solenoid clicks. Then, with the relay terminal

still grounded, shift into low gear, and roll car

forward by hand. Solenoid stem should then move

an additional 3/8", as the pawl engages fully.

These two tests indicate proper blocker action.

Unless both tests are met, the blocker ring is

probably not in the correct position.

3.
Engages with a severe jolt or noise

Insufficient blocker ring friction may cause the ring

to lose its grip on the hub of the sun gear control

plate. Check the fit and tension of the ring as de-

scribed under "Cleaning and Inspection".

4.
Free-wheels at speeds over 30 MPH

If cam roller retainer spring tension is weak the unit

will free wheel at all times. Check spring action as

described under "Cleaning and Inspection".

CHEVROLET CHASSIS SERVICE MANUAL