
ENGINE-ELECTRICAL 6Y-20
cause oxidized contact points. Check for these conditions
where burned contacts are experienced. An
out-of-
balance condition in the ignition system, often the result
of too much or too little condenser capacity, is indicated
where point pitting is encountered.
REPLACEMENT
Four and Six Cylinder Engine Distributor
1.
Release distributor cap hold-down screws, remove
cap and place it out of work area.
2.
Remove rotor.
3.
Pull primary and condenser lead wires from contact
point quick disconnect terminal (fig. 4i).
4.
Remove contact set attaching screw, lift contact point
set from breaker plate.
5.
Clean breaker plate of oil smudge and dirt.
6. Place new contact point assembly in position on
breaker plate, install attaching screw.
CAUTION: Carefully wipe protective film from
point set prior to installation.
NOTE: Pilot on contact set must engage match-
ing hole in breaker plate.
7.
Connect primary and condenser lead wires to quick
disconnect terminal on contact point set. .
8. Check and adjust points for proper alignment and
breaker arm spring tension (fig. 5i). Use an aligning
tool to bend stationary contact support if points need
alignment.
NOTE: The contact point pressure must fall
within specified limits. Weak tension will cause
CONTACT SET
ATTACHING
SCREW
QUICK
DISCONNECT
TERMINAL
BREAKER PLATE
ATTACHING SCREWS
chatter, resulting in arcing and burning of-the
points and an ignition miss at high speed, while
excessive tension will cause undue wear of the
contact points, cam and rubbing block. Breaker
arm spring tension should be 19-23 ounces. The
contact point pressure should be checked with a
spring gauge. The scale should be hooked to the
breaker lever and the pull exerted at 90 degrees
to the breaker lever as shown in Figure 5i. The
reading should be taken just as the points sepa-
rate.
The pressure can be adjusted by bending
the breaker lever spring. If the pressure is ex-
cessive, it can be decreased by pinching the
spring carefully. To increase pressure,, the
lever must be' removed from the distributor so
the spring can be bent away from the lever.
Avoid excessive spring distortion.
9. Set point opening (.019" for new points).
10.
Reinstall rotor, position and lock distributor cap to
housing.
11.
$tart engine and test dwell and ignition timing.
Eight Cylinder Engine Distributor
1.
The contact point set is replaced as one complete
assembly and only dwell angle requires adjustment
after replacement. Breaker lever spring tension and
point alignment are factory set.
2.
Remove the distributor cap by placing a screw driver
in the slot head of the latch, press down and turn 1/4
turn in either direction.
3.
Remove the two attaching screws which hold the base
of the contact set assembly in place.
4.
Remove the primary and condenser leads from their
nylon insulated connection (fig. 6i) in contact set.
5.
Reverse Steps 2, 3 and 4 to install new contact set.
CAUTION:. Install the primary and condenser
leads as shown in Figure 6i. Improper installa-
tion will cause lead interference between the
cap,
weight base and breaker advance plate.
6. If car has 20,000 to 25^000 miles (or sooner if
desired) the cam lubricator wick (fig. 7i) should be
changed. Using long nosed pliers squeeze assembly
together at base and lift out. Remove all old lubri-
cant from cam surface. Replace in same manner.
Fig.
4i—Breaker Plate and Attaching Parts
Fig. 5i—-Checking Breaker Arm Spring Tension
CHEVROLET CHASSIS SERVICE MANUAL

CLUTCH
AND
TRANSMISSIONS
7-20
COMPONENT PARTS REPLACEMENT
3.
4.
5.
6.
TRANSMISSION REPLACEMENT
(EXC.
CORVETTE)
Removal From Vehicle
1.
Remove shift lever trim plate and dust boot.
Remove shift lever assembly.
Raise vehicle
to
desired working height.
Disconnect
the
speedometer cable from speedometer
driven gear fitting.
.
~
. •
Remove propeller shaft, then support engine
at the
oil
pan
rail with
a
jack
or
other suitable support
capable
of
supporting
the
engine when transmission
is removed.
Disconnect shift lever bracket assembly from exten-
sion
and
remove
all 3
transmission shifter levers
from shifter shafts, (leave linkage connected
to
levers)
and
remove bracket assembly levers
and
linkage.
Remove extension mount7 to-crossmember attaching
bolts.
Loosen transmission crossmember
and
move rear-
ward
or
remove.
Remove
the
transmission-to-clutch housing retaining
bolts
and
install two guide pins, J-1126,
in
top holes.
Slide
the
transmission straight back until
the
input
shaft
is
free
of
splines
in the
clutch disc.
Slide
the
transmission rearward
to
allow sufficient
clearance
of
input shaft
and
clutch housing. Then tilt
input shaft
end of
transmission downward and with-
8.
9.
10.
11.
draw transmission from vehicle.
installation
to
Vehicle
1.
Raise transmission
and
rotate
as
necessary-to start
input shaft into clutch disc
and
slide transmission
forward until
it
bottoms against clutch housing.
Re-
move guide pins.
2.
Install
the
transmission-to-clutch housing retaining
bolts.
Torque
all
four retaining bolts
to 50 ft. lbs.
3.
Raise engine
and
position extension mount
to
cross-
member,
and
loosely install
the
retaining bolts.
Tighten crossmember
to
frame retaining bolts.
4.
Remove temporary support from engine, and torque
the extension mount retaining bolts.
5. Install propeller shaft.
6. Install control lever bracket assembly
to
transmis-
sion extension
and
connect shifter levers
to
shifter
shafts.
7. Fill transmission
to
level
of
filler plug hole with
correct lubricant specified
in
Section
0.
8. Lower vehicle and install shift lever assembly, check
shift pattern and adjust linkage
as
required.
9. Install trim plate and dust boot.
CORVETTE TRANSMISSION REPLACEMENT
Refer
to
similar procedure under 3-Speed Corvette
Transmission.
FOUR-SPEED (SAGINAW) TRANSMISSION
INDEX
Page
General Description
7-20
Maintenance
and
Adjustments
. . 7-21
Shift Linkage Adjustment.
. 7-21
Speedometer Driven Gear
and
Oil Seal ................
(See
Muncie 4-Speed)
Side Cover
7-22
Page
Removal
. . , 7-22
Disassembly
. . 7-22
Assembly
. . . 7-22
Installation
. 7-22
Extension
Oil
Seal
(See
Muncie 4-Speed)
Transmission Replacement (See Muncie 4-Speed)
GENERAL DESCRIPTION
The Saginaw four speed fully synchronized
(all
forward
gears) transmission incorporates helical drive gears
throughout.
The main drive gear
is
supported
by a
ball bearing
at
the front
end of the
transmission case and
is
piloted
at its
front
end in an oil
impregnated bushing mounted
in the
engine crankshaft.
The
front
end of the
mainshaft
is
piloted
in a row of
roller bearings
set
into
the
hollow
end
of
the
main drive gear
and the
rear end
is
carried
by a
ball bearing mounted
in the
front
of the
extension housing.
The countergear
is
carried
on a
single
row of
rollers
at both ends while thrust
is
taken on thrust washers
lo-
cated between
the
ends
of the
gear and
the
thrust bosses
in
the
case. Ah anti-rattle plate assembly
at the
front
of
the countergear provides
a
constant spring tension
be-
tween
the
counter
and
clutch gears
to
reduce torsional
vibrations.
The
sliding reverse idler gear
is
carried
on
a bushing finish bored
in
place.
It
rotates
on a
short
idler shaft retained by
a
woodruff
key.
The synchronizer assemblies consist
of a
clutch
hub,
clutch sleeve,
two
clutch
key
springs and three energizer
clutch keys
and are
retained
as an
assembly on
the
main
shaft
by a
snap ring.
A great deal
of
similarity
and
interchangeability
now
exists between
the new 3 and
4-speed Saginaw trans-
missions.
However,
the
synchronizer assembly
at the
front
of the
mainshaft
is
used
for the
third and fourth rather than
the
second
and
third shift.
The
synchronizer assembly
at
the rear
of the
mainshaft
is
used
for the
first and second
rather than
the
first
and
reverse shift. Gear teeth
cut
in
the
first and second synchronizer sleeve (reverse gear)
distinguish
it
from
the
third
and
fourth synchronizer
sleeve.
Starting from
the
front, gears
on the
mainshaft
are
third, second
and
first rather than second, first and
re-
verse.
A
fourth blocker ring
is
used between
the 1-2
synchronizer assembly
and
first gear
on the
four-speed
transmissions.
The cover
on the new
four-speed transmission
is lo-*
cated
on the
left-hand side
of the
case.
It is
similar
to
the three-speed cover with
the
addition
of a
reverse
shifter shaft assembly, detent ball
and
detent spring.
Disassembly
and
assembly procedures
are
covered
in
this section.
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

CLUTCH AND TRANSMISSIONS 7-24
is at the full mark on the dip stick, it is just slightly be-
low the planetary gear unit. If additional oil is added,
bringing the oil level above the full mark, the planetary
unit will run in the oil, foaming and aerating the oil. This
aerated oil carried through the various oil pressure pas-
sages (low servo, reverse servo, clutch apply, converter,
etc.) may cause malfunction of the transmission assem-
bly, resulting in cavitation noise in the converter and
improper band or clutch application. Overheating may
also occur.
If the transmission is found consistently low on oil, a
thorough inspection should be made to find and correct
all external oil leaks.
PERIODIC OIL CHANGE
The transmission oil should be changed periodically as
recommended in Section 0, and whenever transmission is
to be removed from the vehicle for repairs.
1.
Run engine for one minute in neutral prior to chang-
ing.
2.
Be sure vehicle is level or raise from the rear only.
3.
Remove the oil pan drain plug and allow oil to drain
thoroughly into a pan or can.
Replace drain plug and refill with approximately two
quarts of oil specified in Section 0.
NOTE: To refill the transmission, remove dip
stick from oil filler tube and refill transmission
with oil specified in Section 0 using filler tube
and funnel J-4264. Then, after shifting into all
ranges at idle speed to fill all oil passages, the
engine should be run at 800-1000 rpm with the
transmission in Neutral until the oil warms up,
then add oil as required to raise the fluid level
to the full mark on the dip stick. Refill capacity
is approximately 2 qts.
4.
Fig.
1PG - Adjusting Low Band Using J-21848
PERIODIC LOW BAND ADJUSTMENT (Fig. 1PG)
Low band adjustment should be periodically performed
at 12,000 mile intervals, or sooner, as necessary if op-
erating performance indicates low band slippage.
1.
Raise vehicle and place selector lever in neutral.
2.
Remove protective cap from transmission adjusting
screw.
3.
a. On Corvette Models: Drop left exhaust pipe for
clearance.
b.
On Chevelle Models: To gain clearance between
underbody and transmission, it may be necessary
to remove rear mount bolts from crossmember,
and move transmission slightly toward passenger
side of vehicle. .
4.
Loosen adjusting screw lock nut 1/4 turn and hold in
this position with wrench.
5.
Using Special Tool J-21848 adjust band to 70 in. lbs.
and back off four (4) complete turns for a band which
has been in operation for 6,000 miles or more,.or
three (3) turns for one in use less than 6,000 miles.
CAUTION: Be sure to hold the adjusting screw
lock nut at 1/4 turn loose with a wrench during"
the.adjusting procedure.
6. Tighten the adjusting screw lock nut to specified
torque.
CAUTION: The amount of back-off is not an
approximate figure, it must be exact.
MANUAL SHIFT LINKAGE CHECK & ADJUST
(Column Type)
1.
The shift tube and lever assembly must be free in the
mast jacket. See Section 9 for alignment of steering
column assembly if necessary.
2.
To check for proper shift linkage adjustment, lift
the transmission selector lever towards the steering
wheel. Allow the selector lever to be positioned in
drive (D) by the transmission detent.
NOTE: Do not use the indicator pointer as a
reference to position the selected lever. When
performing linkage adjustment, pointer is ad-
justed last.
3.
Release the selector lever. The lever should be in-
hibited from engaging low range unless the lever is
lifted.
4.
Lift the selector lever towards the steering wheel,
and allow the lever to be positioned in neutral (N) by
the transmission detent.
5.
Release the selector lever. The lever should now
be inhibited from engaging reverse range unless the
lever is lifted.
6. A properly adjusted linkage will prevent the selector
lever from moving beyond both the neutral detent, and
the drive detent unless the lever is lifted to pass
over the mechanical stop in the steering column.
7.
In the event that an adjustment is required, place
the selector lever in drive (D) position as determined
by the transmission detent. See Steps 2 and 3.
8. Loosen the adjustment swivel at the cross-shaft,
and rotate the transmission lever so that it contacts
the drive stop in the steering column.
9. Tighten the swivel and recheck the adjustment. See
2 and 6.
CHEVROLET CHASSIS SERVICE MANUAL

CLUTCH AND TRANSMISSIONS 7-36
TURBO HYDRA-MATIC TRANSMISSION
INDEX
Page
General Description . . , . 7-36
Maintenance and Adjustments . 7-37
Transmission Fluid 7-37
Fluid Level Indicator 7-37
Shift Control Linkage Adjustment ........... 7-37
Neutral Safety Switch Adjustment 7-37
Draining and Refilling Transmission . . . 7-37
Pressure Regulator Valve 7-38
Control Valve Body . 7-39
Governor ..'.... 7-40
Modulator and Modulator Valve 7-40
Parking Linkage . . 7-40
Page
Rear Seal -. 7-40
Other Service Operations . . 7-40
Transmission Replacement 7-40
Turbo Hydra-Matic Diagnosis Procedure. ......... 7-41
Sequence . ; ; 7-41
Oil Level and Condition Check 7-41
Manual Linkage 7-41
Oil Leaks .' 7-41
Case Porosity - Repair ................ 7-42
Oil Pressure Check 7-42
Transmission Shift Points 7-42
Special Tools 7-43
GENERAL DESCRIPTION
The Turbo Hydra-Matic transmission is a fully auto-
matic unit consisting primarily of a 3-element hydraulic
torque converter and a compound planetary gear set.
Three multiple-disc clutches, one sprag unit, one roller
clutch and two bands provide the friction elements re-
quired to obtain the desired function of the compound
planetary gear set.
The torque converter couples the engine to the plane-
tary gears through oil and provides hydraulic torque
multiplication when required. The compound planetary
gear set produces three forward speeds and reverse.
The
3-
element torque converter consists of a pump or
driving member, a turbine or driven member, and a
stator assembly. The stator is mounted on a one-way
roller clutch which will allow the stator to turn clock-
wise but not counter-clockwise.
The torque converter housing is filled with oil and
is attached to the engine crankshaft by a flex plate and
always rotates at engine speed. The converter pump is
an integral part of the converter housing, therefore the
pump blades, rotating at engine speed, set the oil within
the converter into motion and direct it to the turbine,
causing the turbine to rotate.
As the oil passes through the turbine it is traveling in
such a direction that if it were not re-directed by the
stator it would hit the rear of the converter pump blades
and impede its pumping action. So at low turbine speeds,
the oil is re-directed by the stator to the converter pump
in such a manner that it actually assists the converter
pump to deliver power or multiply engine torque.
As turbine speed increases, the direction of the oil
leaving the turbine changes and flows against the rear
side of the stator vanes in a clockwise direction. Since
the stator is now impeding the smooth flow of oil, its
roller clutch releases and it revolves freely on its shaft.
Once the stator becomes inactive, there is no further
multiplication of engine torque within the converter. At
this point, the converter is merely acting as a fluid
coupling as both the converter pump and turbine are
being driven at approximately the same speed - or at a
one-to-one ratio.
A hydraulic system pressurized by a gear type pump
provides the working pressure required to operate the
friction elements and automatic controls.
External control connections to transmission are:
Manual Linkage
Engine Vacuum
12 Volt Electrical
Signal
To select the desired op-
erating range.
To operate a vacuum mod-
ulator unit.
To operate an electrical
detent solenoid.
A vacuum modulator is used to automatically sense
any change in the torque input to the transmission. The
vacuum, modulator transmits this signal to the pressure
regulator for line pressure control, to the 1-2 accumula-
tor valve, and to the shift valves so that all torque re-
quirements of the transmission are met and smooth
shifts are obtained at all throttle openings.
The detent solenoid is activated by an alectric switch
on the carburetor. When the throttle is fully opened, the
switch on the carburetor is closed, activating the detent
solenoid and. causing the transmission to downshift at
speeds below approximately 70 MPH.
The selector quadrant has six selector positions: P,R,
N,D,
L2,L1.
P.
*
- Park position positively locks the output shaft to
the transmission case by means of a locking pawl
to prevent the vehicle from rolling in either di-
rection. The engine may be started in Park
position.
R. - Reverse enables the vehicle to be operated in a
reverse direction.
N.
- Neutral position enables the engine to be started
and run without driving the vehicle.
D,
- Drive Range is used for all normal driving condi-
tions and maximum economy. Drive Range has
three gear ratios, from the starting ratio to
direct drive. Detent downshifts are available by
depressing the accelerator to the floor.
L2.
- L2 Range has the same starting ratio as Drive
Range, but prevents the transmission from shift-
ing above second speed to retain second speed
acceleration when extra performance is desired.
L2 Range can also be used for engine braking.
L2 Range can be selected at any vehicle speed,
and the transmission will shift to second gear and
remain in second until the vehicle speed or the
throttle are changed to obtain first gear operation
in the same manner as in D Range.
CHIVROLET CHASSIS SERVICE MANUAL

CLUTCH AND TRANSMISSIONS 7-37
LI.
- LI Range can be selected at any vehicle speed,
and the transmission will shift to second gear
and remain in second until vehicle speed is re-
duced to approximately 40 MPH, .depending on
axle ratio. LI Range position prevents the trans-
mission from shifting out of first gear.
It is very important that any communication concerning
the Turbo Hydra-Matic always contain the transmission
serial number and that all transmission parts returned
to Chevrolet Motor Division always be tagged with the
transmission serial number.
MAINTENANCE AND ADJUSTMENTS
TRANSMISSION FLUID
Transmission fluid level should be checked with trans-
mission warm and selector lever in "P" Park position,
every time engine oil level is checked or as specified in
Section 0 when engine oil is changed.
CAUTION: Since the Turbo Hydra-Matic trans-
mission is very sensitive to oil level, special
precautions should be taken when checking the
oil level, to insure against an overfifE
Transmission fluid should be changed as specified in
Section 0.
FLUID LEVEL INDICATOR
The fluid level indicator is located in the filler pipe at
the right rear corner of the engine. To bring the fluid
level from the add mark to the full mark add 1 pint.
Fluid level should be to the full mark with transmission
at normal operating temperature. With cold fluid the
level should be at the add mark or slightly below.
SHIFT CONTROL LINKAGE ADJUSTMENT
Adjust linkage as shown below and in Figure 2.
1.
The shift tube and lever assembly must be free in the
mast jacket See Section 9 for alignment of steering
column assembly if necessary.
2.
To check for proper shift linkage adjustment, lift the
transmission selector lever towards the steering
wheel. Allow the selector lever to be positioned in
drive (D) by the transmission detent.
NOTE: Do not use the indicator pointer as a
reference to position the selector lever. When
performing linkage adjustment, pointer is ad-
justed last.
3.
Release the selector lever. The lever should be in-
hibited from engaging low range unless the lever is
lifted.
4.
Lift the selector lever towards the steering wheel,
and allow the lever to be positioned in neutral (N) by
the transmission detent.
5.
Release the selector lever. The lever should now be
inhibited from engaging reverse range unless the
lever is lifted.
6. A properly adjusted linkage will prevent the selector
lever from moving beyond both the neutral detent,
and the drive detent unless the lever is lifted to pass
over the mechanical stop in the steering column.
See schematic diagram.
7.
In the event that an adjustment is required, place the
selector lever in drive (D) position as determined by
the transmission detent. See Steps 2 and 3.
8. Loosen the adjustment swivel at the cross-shaft, and
rotate the transmission lever so that it contacts the
drive stop in the steering column.
9. Tighten the swivel and recheck the adjustment. See
Steps 2 and 6. -
l(h Readjust indicator needle if necessary to agree with
the transmission detent" positions. See Section 9.
11.
Readjust neutral safety switch if necessary to pro-
vide the correct relationship to the transmission de-
tent positions. See Section 12.
12.
When properly adjusted the following conditions must
be met by manual operation of the steering column
shift lever:
a. From reverse to drive position travel, the trans-
mission detent feel must be noted and related to
indicated position on dial.
b.
When in drive and reverse positions, pull lever
rearward (towards steering wheel) and then re-
lease. It must drop back into position with no
restrictions.
NEUTRAL SAFETY SWITCH ADJUSTMENT
The neutral safety switch must be adjusted so that the
car will start in the park or neutral position, but will not
start in the other positions. For replacement refer to
Section 12 of this Manual.
DRAINING AND REFILLING TRANSMISSION
Drain oil immediately after operation before it has had
an opportunity to cool.
To drain oil proceed as follows:
1.
Remove bottom pan attaching screws, pan, and gas-
ket.
2.
Remove oil strainer. Remove "O" ring seal from
pick-up pipe and discard.
3.
Discard strainer if dirty.
4.
Install new "O" ring seal on pick-up pipe and install
strainer and pipe assembly.
5.
Thoroughly clean bottom pan.
6.. Affix new gasket to bottom pan with petroleum jelly.
7.
Install bottom pan with attaching screws and torque
to specifications;
8. If only the pan has been removed, pour approximately
7-1/2 pints of fluid into the transmission. If the
valve body has also been removed use 9-1/2 pints.
After a complete overhaul approximately 19 pints
are required. Be sure container, spout, or funnel is
clean.
9. Start engine and let idle (carburetor off fast idle
step).
Place selector lever in P position and apply
hand brake.
10.
With transmission warm (approximately 150°F), add
fluid to bring level to full mark on indicator.
CAUTION: Do not overfill. Foaming will re-
sult.
CHEVROLET CHASSIS SERVICE MANUAL

STEERING 9-35
Fig.
66—Power Steering Diagnosis
shown in Figure 66. Gauge must be between shut-
off valve and pump. Open shut-off valve,
b.
Remove filler cap from pump reservoir and check
fluid level. Fill pump reservoir to full mark on
dip stick. Start engine and, holding steering
wheel against stop, check connections at Tool
J-5176 for leakage. Bleed system as outlined
under Maintenance and Adjustments. Insert ther-
mometer (Tool J-5421) in reservoir filler open-
ing. Move steering wheel from stop to stop
several times until thermometer indicates that
hydraulic fluid in reservoir has reached tempera-
ture of 150° to 170°F.
CAUTION: To prevent scrubbing flat spots on
tires,
do not turn steering wheel more than five
times without rolling car to change tire-to-floor
contact area.
c. Hold steering wheel against a stop momentarily
and read pressure gauge. If the maximum pres-
sure is below specifications, a faulty hydraulic
circuit is indicated. To determine which part is
faulty, proceed with test number two.
Test Number Two—Oil Circuit Closed
a. Slowly turn shut-off valve on J-5176 to closed
position and read pressure indicated on gauge.
Quickly reopen valve to avoid pump damage, if
indicated pressure is less than specification,
pump output is below requirement and pump may
be considered faulty. If pressure indicated is
within specifications, it may be safely assumed
that the external hoses, connections, valve and
adapter or steering gear is at fault.
NOTE:
If pump proves faulty in test number
two,
test should be repeated after pump is re-
paired and installed in vehicle. This will provide
a means of checking the repairs made to the
pump and the condition of the steering gear or
valve and adapter which may also be faulty.
COMPONENT REPLACEMENT AND REPAIRS
POWER STEERING PUMP
Removal (Fig. 67)
1.
Disconnect hoses at pump. When hoses are discon-
nected, secure ends in raised position to prevent
drainage of oil. Cap or tape the ends of the hoses to
prevent entrance of dirt.
NOTE:
Chevelle with 396 engine uses a remote
reservoir. It is necessary to disconnect the
reservoir to pump hose before removing the
pump.
Hold a 1 qt. container under the reservoir
when the hose is removed to catch the fluid.
2.
Install two caps at pump fittings to prevent drainage
of oil from pump.
3.
Remove pump belt.
4.
On Corvette with 427 engine, loosen alternator ad-
justment and remove pump to alternator belt.
5. Remove pump from attaching parts and remove pump
from vehicle.
NOTE:
On Chevrolet and Chevy II equipped with
283 and 327 engine it may be necessary to re-
move pump brace.
6. Remove drive pulley attaching nut.
7. Remove pulley from shaft with Tool J-21239 (for
stamped pulleys) or Tool J-8433-1 with J-8433-2
adapter (for cast iron pulleys). Do not hammer
pulley off shaft as this will damage the pump.
Fig.
67—Power Steering Pump Mounting
CHEVROLET CHASSIS SERVICE MANUAL

WHEELS AND TIRES 10-4
the road and it slips, grinding off the tread on the inside
half of the tire at an excessive rate. This type of tire
shows much the same appearance of tread wear as tire
wear caused by negative camber.
Second, the transfer of weight may also over-load the
outside tires so much that they are laterally distorted
resulting in excessive wear on the outside half of the
tire producing a type of wear like that caused by ex-
cessive positive camber.
Cornering wear can be most easily distinguished from
abnormal camber wear by the rounding of the outside
shoulder or edge of the tire and by the roughening of the
tread surface which denotes abrasion.
Cornering wear often produces a fin or raised portion
along the inside edge of each row in the tread pattern.
In some cases this fin is almost as pronounced as a
toe-in fin, and in others, it tapers into a row of tread
blocks to such an extent that the tire has a definite step
wear appearance.
The only remedy for cornering wear is proper in-
struction of owners.
Fig.
5 - Tire Rotatidh
Rotation
To minimize the possibility of tire noise and to equal-
ize tire wear, it is recommended that tires be inter-
changed every 6000 miles as shown in Figure 5 or more
frequently in the case of extremely heavy wear.
NOTE:
Rotate Corvette tires at 4000 miles or
sooner.
Interchanging tires will effectively prevent undue wear
on any particular tire. II tire interchanging is followed
as recommended above, all tires will have the same
number of miles in each wheel position at the end of the
fourth change. When interchanging tires, inspect for
signs of abnormal wear, bulging, etc., stones, glass, and
nails should be removed before reinstallation.
Noise
Noise caused by the normal action of tire treads on
various road surfaces is often confused with rear axle
gears or other noises in the car.
The determination of whether tires are causing the
noise complained of is relatively simple. The car should
be driven at various speeds and note taken of part
throttle, and sudden acceleration and deceleration. Axle
and exhaust noises show definite variations under these
conditions, while tire noise will remain constant. Tire
noise is, however, most pronounced at speeds of approx-
imately twenty or thirty miles per hour.
The tires may be further checked by driving the ear
over smooth pavement with the tires at normal pressure
and again over the same stretch of pavement when the
tires have been inflated to fifty pounds pressure. Reduce
the tires to normal pressure one at a time to determine
the faulty tire or tires. This high inflation pressure
should immediately be reduced to normal after test. If
the noise for which the test is being made is caused by
tires,.
it will noticeably decrease when the tire pressure
is increased, whereas axle noise should show no change
in volume.
If, on inspection, the tires on the front wheels are
found to be creating most of the noise the alignment of
the front wheels should be checked. Excessive tire noise
usually results from lower than recommended tire pres-
sure, incorrect alignment, uneven tire wear, or defective
(thumper) tire.
Cleaning
A great deal of ordinary road dirt which collects on
white sidewall tires may be sponged off with clear water
or a mild soap solution.
A good brand of whitewall tire cleaner, however, is
a quicker and more effective cleaner for removing dirt
and stains from whitewall tires and in many cases it
will remove stains and discoloration that the simpler
method of soap and water will not remove.
Under no circumstances should gasoline, kerosene or
any cleaning fluid containing a solvent derived from oil
be used to clean whitewall tires. Oil in any form is
detrimental to tire rubber and a cleaner with an oil base
will discolor or injure whitewall tires.
Change (W/Wheels)
To change the road wheels using the jack that comes
with the car, observe the following procedure:
1.
Set hand brake and block front wheels if rear wheel
is being changed.
2.
Remove hub cap or wheel disc and break wheel
mounting nuts loose.
3.
Place the jack as directed tinder, General Informa-
tion,
Section 0 and raise car until wheel clears
ground.
4.
Remove wheel mounting nuts and remove wheel from
hub or drum.
5. To replace road wheel, reverse the above instrue-
. tions. Proper torque on nuts is 55-75 ft. lbs.
torque (70-85 ft. lbs. for Corvette aluminum wheel
nuts).
CAUTION: On models equipped with discs, in-
dex the pilot hole in the disc on the valve stem.
(To insure that the anti-rotation notches in wheel
disc register on lugs in wheel rim.)
CHEVROLET CHASSIS SERVICE MANUAL