
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-28
terminals on eoil. On Corvettes equipped with radio,
remove bolts securing ignition shield over distribu-
tor and coil.
2.
Pull high tension wire from center terminal of coil.
3.
Remove the two coil support mounting bolts or loosen
friction clamp screw and remove coil.
4.
Place new coil in position and install attaching bolts
or tighten clamp screw.
5.
Place high tension lead securely in center terminal
of coil and connect ignition switch and distributor
primary leads to terminals on coil. Replace ignition
shield on Corvettes.
6. Start engine and test coil operation.
IGNITION PULSE AMPLIFIER
DISASSEMBLY
To check the amplifier for defective components, pro-
ceed as follows:
1.
Remove the bottom plate from the amplifier.
2.
To aid in reassembly, note the locations of the lead
connections to the panel board.
3.
Remove the three panel board attaching screws, and
lift the assembly from the housing.
4.
To aid in reassembly, note any identifying markings
on the two transistors and their respective locations
on the panel board and heat sink assembly.
5.
Note the insulators between the transistors.and the
heat sink, and the insulators separating the heat sink
from the panel board.
6. Remove the transistor attaching screws, and sepa-
rate the two transistors and heat sink from the panel
board.
7.
Carefully examine the panel board for evidence of
damage.
MOUNTING
SCREW
RESISTOR R5 jgSfe. / DIODE Dl
TRANSISTOR TR2
(UNDERNEATH)
1H L >©V
[So
To
I
/'%**jt\
\
TRANSISTC>R"""
1 X ^^w^ X \ (UNDERNEATH)
9^ESISTORR^^^H|^^^^^H
^B
RESISTOR
R4
^HPH^^H
WM'
RESISTOR
R3
I^B^^^^I^U
N .6 ®
mm
N%|/MOUNTING
• tr^i^w ^\ vjR SCREW
CAPACITOR
Cl\
pNkj^^A^
\
RESISTOR
Rl
MOUNTING ^55S^^ \ CAPACITOR C3
SCREW I RESISTOR R6 CAPACITOR C2
TRANSISTOR TR3
COMPONENT CHECKS (Figs. \7\ and 18i)
With the two transistors separated from the assembly,
an ohmmeter may be used to check the transistors and
components on the panel board for defects. An ohmmeter
having a 1-1/2 volt cell, which is the type usually found
in service stations, is recommended. The low range
scale on the ohmmeter should be used except where
specified otherwise.
A 25 watt soldering gun is recommended, and a 60% tin
40%
lead solder should be used when re-soldering. Avoid
excessive heat which may damage the panel board. Chip
away any epoxy involved, and apply new epoxy which is
commercially available.
In order to check the panel board assembly, it is
necessary to unsolder at the locations indicated in Fig-
ure 18i the two capacitors C2 and C3. In all of the fol-
lowing checks, connect the ohmmeter as shown and then
reverse the ohmmeter leads to obtain two readings. The
amplifier circuitry is shown in Figure 19i.
1.
Transistors TR1 and TR2: Check each transistor by
referring to Figure 20i. If both readings in Step 1
are zero, the transistor is shorted. If both readings
in Step 2 are zero, the transistor is shorted; and if
both readings are infinite, the transistor is open.
Interpret Step 3 the same as Step 2.
2.
Trigger Transistor TR3:
11
both readings in Step 1
are zero, the transistor is shorted. If both readings
in Step 2 are zero, the transistor is shorted; and if
both readings are infinite, the transistor is open.
Interpret Step 3 the same as Step 2.
3.
Diode Dl: 11 both readings are zero, the diode is
shorted; and if both readings are infinite, the diode
is open.
4.
Capacitor Cl: If both readings are zero, the capaci-
tor is shorted.
5.
Capacitors C2 and C3: Connect the ohmmeter across
CHECKING
RESISTOR Rl
UNSOLDER
I
CHECKING TRIGGER
TRANSISTOR TR3
CHECKING
CAPACITOR C
Fig.
171—Pulse Amplifier Panel Board
Fig.
18i—Pulse
Amplifier
Component
Checks
CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-ELECTRICAL 6Y-32
STARTER CIRCUIT
INDEX
Page
General Description 6Y-32
Maintenance and Adjustments . '. . 6Y-32
Resistance Checks 6Y-32
Starting Motor and Solenoid Check 6Y-33
Page
Service Operations 6Y-33
Starter Motor 6Y-33
Removal and Installation 6Y-33
GENERAL DESCRIPTION
The function of the starting system, composed of the
starting motor, solenoid and battery, is to crank the
engine. The battery supplies the electrical energy, the
solenoid completes the circuit to the starting motor, and
the motor then does the actual work of cranking the
engine.
The starting motor (fig. Is) consists primarily of the
drive mechanism, frame, armature, brushes, and field
windings. The starting motor is a pad mounted 12-volt
extruded frame type, having four pole shoes and four
fields,
connected with the armature. The aluminum drive
end housing is extended to enclose the entire shift lever
and plunger mechanism, protecting them from dirt,
splash, and icing. The flange mounted solenoid switch
operates the overrunning clutch drive by means of a
linkage to the shaft lever.
The V-8 wiring harness differs from the in-line engine
in that the ignition lead to the coil from the switch is at-
tached at the coil instead of at the starter solenoid (fig.
2s).
CONTACT
FINGER
PINION
STOP
BRUSH
INSULATED BRUSH HOLDER \ FIELD COIL
BRUSH SPRING ARMATURE
GROUNDED BRUSH HOLDER
OVERRUNNING
CLUTCH
Fig.
Is—Starting Motor Cross Section (Typical)
MAINTENANCE AND ADJUSTMENTS
No periodic lubrication of the starting motor or sole-
noid is required. Since the starting motor and brushes
cannot be inspected without disassembling the unit, no.
service is required on these units between overhaul
periods.
RESISTANCE CHECKS
Although the starting motor cannot be checked against
specifications on the car, a check can be made for. exces-
sive resistance in the starting circuit. Place a volt-
meter across points in the cranking circuit as outlined
below and observe the reading with the starting switch
closed and the motor cranking (distributor primary lead
grounded to prevent engine firing).
1.
From battery positive post To solenoid battery
terminal.
CHEVROLET CHASSIS SERVICE MANUAL

CLUTCH AND TRANSMISSIONS 7-9
6. Connect speedometer cable.
7. Install propeller shaft assembly.
8. Fill transmission with lubricant specified in Section
O.
CORVETTE TRANSMISSION REPLACEMENT
, 1. Disconnect battery ground cable.
2.
Pisassemble transmission shift control lever by un-
screwing ball from lever, lifting out
"T"
handle re-
turn spring and "T" handle, then remove the anti-
rattle bushings.
3.
Raise front and rear of vehicle.
4.
Insert a block of wood between the top of the dif-
ferential carrier housing and the underbody (to pre-
vent upward travel of the carrier when the carrier
front support is disconnected).
5. Disconnect the differential carrier front supportfrom
its frame bracket, by removing the nut on the under-
side of the biscuit mount.
6. Pry the carrier downward to relieve load while re-
moving the two center mounting bolts from the car-
rier front support. (To pry carrier downward insert
crowfoot end of a pry bar through the opening in the
carrier front support, hooking end of bar over top of
the center mounting bolt pad cast in the underside of
the carrier.)
7. Pivot carrier support downward for access to prop
shaft "U" joint.
8.
.
Disconnect prop shaft front and then rear "U" bolts.
9. Disconnect parking brake cable from ball socket at
idler lever located near center of underbody.
10.
Remove prop shaft by moving shaft forward.
11.
Remove heat deflectors from the right and left ex-
haust pipe.
12.
Remove left bank exhaust pipe.
13.
Remove right bank exhaust pipe and heat riser.
14.
Disassemble the transmission mount, as follows:
a. Remove the two bolts that attach rear mount
cushion to the rear mount bracket.
b.
Support engine under oil pan and raise engine to
remove load from rear mount cushion.
CAUTION: To avoid damage to oil pan, a suit-
able wide base, heavy wood platform should be
placed between the jack pad and the oil pan.
c. Remove the three transmission mount bracket-
to-
crossm ember bolts and remove mount bracket.
d. Remove the two bolts from mount pad to trans-
mission case and remove rubber mount cushion
and exhaust pipe "yoke".
15.
Disconnect transmission linkage by removing the
shift levers at the transmission side cover.
16.
Disconnect speedo cable at transmission extension.
17.
Remove transmission output shaft slip yoke.
NOTE:
The yoke is removed to avoid tearing
the heat reflecting pad on the underbody, when
the transmission is being removed.
18.
Remove two bolts to disconnect the transmission
gearshift control lever and bracket assembly from
its adapter plate on side of transmission. Lower
transmission assembly from the vehicle, letting the
gearshift lever slide down and through the dust boot
in the console.
19.
Remove transmission-to-clutch housing attaching
bolts.
20.
Slide transmission assembly rearward from clutch
and rotate transmission for access to the three flat
head machine screws in the control lever bracket
adapter plate. Remove adapter plate. Rotate trans-
mission back to the upright position.
21.
To allow room for transmission removal slowly
lower the rear of engine until the tachometer drive
cable at the distributor just clears the horizontal
ledge across the front of dash.
CAUTION: The tachometer cable can be easily
damaged by heavy contact with the dash. Slide
transmission rearward out of the clutch, then
tip front end of transmission downward and
lower the assembly from vehicle.
22.
Reinstall transmission assembly by performing above
steps in reverse order.
TRANSMISSION OVERDRIVE
INDEX
Page
General
Description 7-10
Maintenance
and Adjustments 7—10
Governor
Switch and Pinion .............. 7-10
Sun
Gear Solenoid Oil Seal and Control
Cable
Bracket 7-10
Case
Rear Oil Seal 7-10
Removal
7-10
Installation
. . . . . 7-10
Control
Shaft Lever and Oil Seal 7-10
Speedometer
Driven Gear 7-10
Electrical
Unit Checks 7-11
Overdrive
Relay . 7-11
Page
Air
Gap 7-11
Point
Opening 7-11
Closing
Voltage 7-11
Solenoid
. 7-11
Closing
Coil 7-11
Engaging
Spring . - 7-11
Ignition
Grounding Contact . 7-11
Governor
Switch 7-11
Kickdown
Switch 7-11
Diagnosis
- Overdrive 7-12
Mechanical
. 7-12
Electrical
7-13
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 7-13
PULL-IN
WINDING
li
HOLD-IN
WINDING
Fig.
4B -
Overdrive Electrical Circuit Wiring Diagram
ELECTRICAL
Any one of the following general complaints may be due
to electrical trouble in the overdrive circuit.
1.
Does not engage.
2.
Does not release.
3.
Does not kickdown from overdrive.
These troubles may be traced and remedied as de-
scribed in the following paragraphs.
1.
Does not engage
a. With the ignition switch on, ground the "KD" ter-
minal of the solenoid relay with a jumper lead.
If the solenoid clicks, the relay and solenoid cir-
cuits are in operating condition. If no click is
heard in the relay, check the fuse and replace if
defective.
b.
If the fuse is good, use a second jumper lead to
connect the "SOL" and "BAT" terminals of the
relay. If a click is now heard in the solenoid, the
relay is probably at fault and should be repaired
or replaced.
c. If the solenoid does not click in Step b, check the
wiring to the No. 4 terminal of the solenoid and
replace if necessary. If the wiring is not defec-
tive,
the trouble is probably in the solenoid. Re-
move the solenoid cover, examine the solenoid
contacts in series with the pull-in winding and
clean if necessary. Test again for clicks, as in
Step b, after replacing solenoid cover and lead
wires.
Replace the solenoid if trouble has not
been corrected.
d. If the relay and solenoid circuits are in good con-
dition as determined in Step a, leave the ignition
switch on and make sure the manual control knob
is in the overdrive position. Ground one and then
the other of the two terminals next to the stem of
the kickdown switch (identified as "SW" and
?fREL"). K the solenoid clicks when one terminal
is grounded but not the other, replace the switch.
If the solenoid does not click when either of the
terminals is grounded, check the wiring between
the relay and the kickdown switch and replace if
defective.
e. If the solenoid clicks as each terminal is grounded
in Step d, ground the governor switch terminal.
If the solenoid clicks, the governor switch may be
defective. If the solenoid does not click, check
the wiring between the kickdown and governor
switches and replace if necessary.
2.
Does not release
a. Remove the connection to the "KD" terminal of
the relay. If this release overdrive, look for a
grounded control circuit between the relay and
governor switch.
b.
If the overdrive is not released in Step a, dis-
connect the lead to the "SOL" terminal of relay.
If this releases the overdrive, replace the relay.
3.
Does not kickdown from overdrive
a. With the engine running, connect a jumper lead
between the No. 6 terminal of the solenoid and
ground. Operate the kickdown switch by hand.
This should stop the engine. If it does, the sole-
noid is probably defective and it should be checked
for dirty ground-out contacts or other defects
within the ground-out circuit of the solenoid (fig.
4B).
Clean the contacts or replace the contact
plate as required.
b.
If the engine does not stop in Step a, ground one
and then the other of the two terminals (Identified
as "IGN" and "SOL") farthest from the sfem of
the kickdown switch. The engine should stop when
one of the two terminals (IGN) is grounded. If
the engine does not stop when the terminal is
grounded, the wiring or connections to the switch
between the switch and coil are defective. When
the btlier terminal (SOL) is grounded, the engine
should stop when the kickdown switch is operated.
If the engine does not stop when the kickdown
switch is operated with the second terminal
grounded, the kickdown switch is defective. If
the trouble is in the kickdown switch, adjust the
linkage to give more travel of the switch rod.
If this does not correct the trouble, replace the
kickdown switch.
If the kickdown switch operates as it should,
check for an open circuit in the wiring between
the kickdown switch and the No. 6 terminal of the
solenoid.
c. If the trouble is not located by the above checks,
the upper contacts of the kickdown switch may not
be opening. To check for this condition, ground
the overdrive control circuit at the governor
switch. This should cause the solenoid to click.
Operate the kickdown switch by hand. This should
cause a second click as the solenoid releases.
If there is no second click, adjust the linkage to
give more travel of the switch rod. If this does
not correct the trouble, replace the kickdown
switch.
CHEVROLET CHASSIS SERVICE MANUAL

CLUTCH
AND
TRANSMISSIONS
7-23
Assembly (Fig.
4X)
1.
With detent spring tang projecting
up
over
the 3rd
and
4th
shifter shaft cover opening install
the
first
and second detent
cam
onto
the
detent
cam
pivot
pin.
With
the
detent spring tang projecting
up
over
the
first
and
second shifter shaft cover hole install
the
3rd
and 4th
detent
cam,
NOTE:
The 1-2
detent
cam has a
.090" greater
contour
on the
inside detent notch.
2.
3.
Install detent
cam
retaining
"C"
ring
to
pivot shaft,
and hook spring into detent
cam
notches.
Install
1-2 and 3-4
shifter shaft assemblies
in
cover
being careful
not to
damage seals. Install both shift
forks
to
shifter shaft assemblies, lifting
up on
detent
cam
to
allow forks
to
fully seat into position.
4.
Install reverse detent ball
and
spring
to
cover, then
install reverse shifter shaft assembly
to
cover.
5.
Install outer shifter levers, flat washers, lock wash-
ers
and
bolts.
Installation
1.
Shift shifter levers into neutral detent (center) posi-
tion. Position cover gasket
on
case.
2.
Carefully position side cover into place making sure
the shift forks
are
aligned with their respective
mainshaft clutch sliding sleeves.
Install cover attaching bolts
and
tighten evenly
to
specified torque.
Remove filler plug
and add
lubricant specified
in
Section
0, to
level
of
filler plug hole.
3.
4.
ALUMINUM POWERGLIDE
INDEX
Page
General
Description
7-23
Maintenance
and
Adjustments .............. 7—23
Oil
Level Check
7-23
Periodic
Oil
Change
7-24
Periodic
Low
Band Adjustment
7-24
Manual
Shift Linkage Check
and
Adjust
7-24
Floor
Shift Linkage
7-25
Floor
Mounted Control Lever
and
Bracket
Assembly
7-29
Throttle
Valve Linkage
.... 7-29
Neutral
Safety Switch
.. . 7-30
Throttle
Return Check Valve (Dashpot)
7-30
Component
Parts Replacement
7-30
Transmission
Replacement .............. 7—30
Page
Other
Service Operations
7-32
Diagnosis
7-32
Warming
Up
Transmission
7-32
Shop
Warm
Up , 7-32
Road
Warm
Up 7-32
Checking
Fluid Level
and
Condition
7-32
Manual
Linkage
7-32
Oil
Leaks
7-33
Basic
Pressure Checks
7-33
Wide
Open Throttle Upshift Pressure Check
.... 7-33
Idle
Pressure
in
Drive Range
7-33
Manual
"Low"
Range Pressure Check .......
7-33
Drive
Range Overrun (Coast) Pressure
.
.......
7-33
Powerglide
Shift Points
. . 7-35
GENERAL DESCRIPTION
The case
and
converter housing
of the two
speed alumi-
num Powerglide Transmission
is a
single case aluminum
unit. When
the
manual control
is
placed
in the
drive
po-
sition,
the
transmission automatically shifts
to low
gear
for initial vehicle movement.
As the car
gains speed
and
depending
on
load
and
throttle position,
an
automatic shift
is made
to
high gear.
A
forced downshift feature
pro-
vides
a
passing gear
by
returning
the
transmission
to low
range.
The
oil
pump assembly
is a
conventional gear type
and
the
oil
pump housing
is of the
large diameter type acting
as
the
front bulkhead
of the
transmission.
The
torque
converter
is a
conventional three element welded design
bolted
to the
engine flywheel which drives through
a
two-
speed planetary gearset.
The
high clutch assembly
is
typical
of the
designs used
in
this type transmission.
The
aluminum Powerglide uses
an
output shaft mounted
gov-
ernor which requires
a
hole through
the
output shaft.
The
reverse clutch assembly
is a
multiple disc type clutch.
The steel plates
are
splined directly
to the
case while
the
face plates
are
splined
to the
internal
or
ring gear.
The
clutch piston operates within
the
rear portion
of the
case.
The internal diameter
of the
pistoh
is
sealed to
an
integral
hub portion
of the
case rear bulkhead.
The
outside
dia-
meter
is
sealed
to a
machined portion
of the
case.
The
piston
is
hydraulically applied
and is
released
by
separate
coil springs.
The
valve body assembly
is
bolted
to the
bottom
of the
transmission case
and is
accessible
for
service
by
removing
the oil pan
assembly.
The
valve
body consists
of an
upper
and
lower body located
on
either
side
of a
transfer plate.
The
vacuum modulator
is lo-
cated
on the
left rear face
of the
transmission case.
The
modulator valve bore
is
located
in the
upper valve body.
MAINTENANCE
AND
ADJUSTMENTS
OIL LEVEL CHECK
The transmission
oil
level should
be
checked period-
ically
as
recommended
in
Section
0. Oil
should
be
added
only when level
is on or
below
the
"ADD" mark
on the dip
stick with
oil hot or at
operating temperature.
The oil
level
dip
stick
is
located
at the
right rear
of the
engine
compartment. Fill with
oil
specified
in
Section
0.
In order
to
check
oil
level accurately,
the
engine should
be idled with
the
transmission
oil hot and the
control
lever
in
neutral (N) position.
It
is
important that
the oil
level
be
maintained
no
higher than
the
"FULL" mark
on the
transmission
oil
level gauge.
DO NOT
OVERFILL,
for
when
the oil
level
CHEVROLET CHASSIS SERVICE MANUAL

CHASSIS SHEET METAL 11-6
NOTE:
All gap tolerances
between hood & adjacent
panels to be held constant
as far as possible.
FLUSH
TO .06
OVER
DOOR
HOOD
TO
FENDER
FLUSH
TO .06 LOW
12 - .17 REF. AT
RAD.
SUPT.
.18 it .04
.07 TO J3l.
OVER
DOOR
FLUSH
TO .06
OVER
DOOR
X
.09 ± .06
.75
± .40 REF.
NOTE:
washer (Section 14)
to align front bumper
parallel to grille bars
NOTE:
Adjust grille ext.
molding to line up with
hood molding ± .03
Fig.
5 - Sheet Metal Adjustments - Chevelle
HOOD ASSEMBLY (Fig. 10)
Hood may be removed either with or without hinges.
To shorten aligning time, scribe a mark on hood around
the hinge plate. See adjustment procedures in this sec-
tion for hood adjustment. Hood hinge springs may be
easily and safely removed and installed using Tool J-9559
as follows:
1.
Remove bolt from Tool J-9559.. Open hood far
enough to allow passage of tool between hood and
fender and insert encls of tool between coils of spring
until barrel of tool contacts outer diameter of spring.
2.
Open hood full while holding spring (with tool in-
stalled) in hand; when hood is in opened position,
remove spring as shown in Figure 11. .
3.
When spring is removed, insert long bolt supplied
with J-9559 through holes in ends of tool, passing it
through spring, and install nut on bolt.
Spring may be removed from J-9559, or J-9559 may
be installed in a new spring by the following method:
1.
Place a closed 6. or 8. inch "CTt clamp in a vise or
fasten it to a' heavy bench top (bench should be fas-
tened to floor).
2.
Hook one end of spring in clamp and the other end
in hook of hoist as shown in Figure 12.
3.
Stretch the spring enough to allow insertion of
J-9559. Install bolt if spring is not to be installed
on hinge at once.
CHEVROLET CHASSIS SERVICE MANUAL