1967 CHEVROLET CAMARO turn

CLUTCH AND TRANSMISSIONS 7-10 ,

GENERAL DESCRIPTION

The overdrive unit is essentially a two-speed planetary-

transmission attached to the rear of a conventional three-

speed transmission. In overdrive, engine speed is ap-

proximately 30 per cent slower at a given road speed

since the drive train includes planetary gears which pro-

vide a lower overall gear ratio than that obtained in high

gear with the conventional transmission.

The electrical equipment which controls the automatic

action of the mechanical portion of the overdrive unit

consists of a solenoid, a speed-sensitive governor switch,

a relay and a kickdown switch. The circuit including this

equipment makes it possible to operate in overdrive above

a pre-set cut-in speed, or in .conventional drive at any

speed.

With the overdrive unit engaged, the transmission

should not be left in any forward gear with intent of lock-

ing the drive-line as the overrunning clutch is a free-

wheeling condition.
SERVICING THE OVERDRIVE

With the,overdrive assembly removed from the trans-

mission, service operations on the transmission proper

are the same as for the standard three-speed trans-

mission.

Repairs to the overdrive housing, output shaft, ring

gear assembly, clutch cam, roller retainer, pinion cage,

sun gear, shift rail, sun gear control plate, output shaft

bearing, oil seal, speedometer drive gear, solenoid pawl

and interlock plunger may be performed underneath the

car, if so desired, by removing the overdrive housing

without disturbing the transmission. Refer to Overhaul

Manual for Service Procedure.

If the transmission mainshaft, overdrive adapter or

transmission rear bearing which is retained in adapter

require replacement, the entire transmission and over-

drive assembly should be removed and overhauled on the

bench.

MAINTENANCE AND ADJUSTMENTS

Servicing of the overdrive governor switch and pinion,

the sun gear solenoid, oil seal and cable bracket, the out-

put shaft rear oil seal, the control shaft lever, and the

speedometer driven gear may be accomplished without

removing the overdrive from the vehicle, as discussed

in the following paragraphs:

GOVERNOR SWITCH AND PINION

To remove governor switch, disconnect wires at gover-

nor switch and screw governor
out
of housing, using Tool

J-4653 on the flat hexagonal surface of governor case.

The pinion may be separated from the governor by re-

moving the snap ring on the shaft.

SUN GEAR SOLENOID, OIL SEAL AND

CONTROL CABLE BRACKET

Remove the solenoid by taking out the two mounting

bolts and lock washers, removing
the.
cable bracket with

the lower bolt. Turn the solenoid 1/4 turn and
pull,
sole-

noid plunger out of adapter. The oil seal may be pried

out of the adapter.

CASE REAR OIL SEAL

Removal

1.
Remove propeller shaft as outlined in Section 4.

2.
Using a punch against seal in housing, pry out seal

from housing.

Installation

1.
Prelubricate between sealing lips and coat outside of

new oil seal with a suitable sealant, then start seal

into bore in overdrive housing.

2.
Using Tool J-5154 drive oil seal into counterbore.

3.
Install propeller shaft as outlined in Section 4.

CONTROL SHAFT LEVER AND/OR "O" RING

OIL SEALS

To remove- the control shaft, disconnect the cpntrol
cable, remove tapered pin and pull lever out. Replace

the two "0" ring seals on the control shaft. Insert shaft

and new "O" ring seals into housing and install tapered

pin. Connect control wire to lever.

SPEEDOMETER DRIVEN GEAR

Disconnect speedometer cable, remove lock plate to

housing bolt and lock washer and remove lock plate. In-

sert screw driver in lock plate slot in fitting and pry

fitting, gear and shaft from housing. Pry "O" ring from

groove in guide.

Install new "O" ring in groove in fitting and insert

shaft.

Hold the assembly so slot in fitting is toward lock plate

boss on housing and install in housing. Push fitting into

housing until lock plate can be inserted in groove and

attached to housing.

L
dl

ZAIR GAP

km (CHECK WITH

M*= POINTS BARELY
'A

AoWER
|^

POINT

0 ADJUST

=^ i
SUPPORT

Fig. IB - Checking Relay Air Gap

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

CLUTCH AND TRANSMISSIONS 7-19

2.
With handle in full down position—adjust cable to ac-

quire dimension shown, be certain that cable is pulled

taut.

3.
Tighten set screw to 15-20 in. lbs.

4.
Bend excess wire and cut - be certain that wire does

not interfere with I.D. of lever or threads of shifter

knob.

NOTE: Handle must return freely from any

position.

SPEEDOMETER DRIVEN GEAR AND OIL SEAL

Replacement

Disconnect speedometer cable, remove retainer to

housing bolt and lock washer and remove retainer. In-

sert screw driver in slot in fitting and pry fitting, gear

and shaft from housing. Pry "O" ring in groove in fitting.

Install new "O" ring in groove and insert shaft Hold

the assembly so slot in fitting is toward boss on housing

and install in housing. Push fitting into housing until re-

tainer can be inserted in groove and install retainer lock

washer and bolt.
Fig.
5M - Installing Side Cover Assembly

TRANSMISSION SIDE COVER

Removal

1.
Disconnect control rods from levers.

2.
Shift transmission into second speed before removing

cover, by moving 1-2 (Rear Cover) shifter lever into

forward detent position.

3.
Remove cover assembly -from transmission case

carefully and allow oil to drain.

Disassembly (Fig. 4M)

1.
Remove the outer shifter lever nuts,*lock washers

and flat washers. Pull levers from shafts.

2.
Remove both shift forks from shifter shaft and detent

plate assemblies. Remove both shifter shaft assem-

blies from cover. Lip seals in side cover may now

be pryed out if replacement is required because of

damage.

1-2 DETENT CAM DETENT SPRING
3-4 DETENT CAM

1-2 SHIFTER SHAFT

1-2 SHIFT FORK
3-4 SHIFT

FORK

DETENT CAM \ 3-4 SHIFTER SHAFT

RETAINER RING

DETENT CAM PIVOT PIN
3.
Remove detent cam spring and pivot retainer "C"

ring. Remove both detent cams.

4.
Replace necessary parts.

Assembly (Fig. 4M)

1.
Install 1-2 detent cam to cover pivot pin first, then

install 3-4 detent cam so the detent spring notches

are offset or opposite each other. Detent cam

notches must be facing downward.

2.
Install detent cam retaining "C" ring to pivot shaft,

and hook spring into detent cam notches.

3.
Install both shifter shaft assemblies in cover being

careful not to damage lip seals. Install both shift

forks to detent plates, lifting up on detent cam to

allow forks to fully seat into position.

4.
Install outer shifter levers, flat washers, lock wash-

ers and nuts.

Installation (Fig. 5M)

1.
Shift 1-2 shifter lever into second speed (forward)

position. 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.

3.
Install cover attaching bolts and tighten evenly to

15-20 ft. lbs. torque.

4.
Remove filler plug and add lubricant specified in

Section 0, to level of filler plug hole.

EXTENSION OIL SEAL

Replacement

1.
Remove propeller shaft.

2.
Pry out the extension oil seal.

3.
Prelubricate between sealing lips and press new oil

seal carefully into place in extension using J-5154 or

similar tool.

Fig.
4M - Transmission Side Cover/ Shift Fork and

Detent Assembly
CAUTION: Do not excessively force the seal

against the seat in the extension.

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 7-25

Fig.
2PG - Chevrolet Shift Linkage Adjustments

10.

11.
Readjust indicator needle if necessary to agree with

the transmission detent positions. See Section 9.

Readjust neutral safety switch if necessary to pro-

vide the correct relationship to the transmission

detent positions. See Section 12.

CAUTION: Any inaccuracies in the above ad-

justment may result in premature failure of the

transmission due to operation without controls

in full detent. Such operation results in reduced

oil pressure and in turn partial engagement of

the affected clutches. Partial
of the

clutches with sufficient pressure to cause ap-

parent normal operation of the vehicle will

result in failure of the clutches or other in-

ternal parts after only a few miles of operation.

Floor Shift Linkage

Chevrolet Linkage Adjustment (Fig. 6PG)

1.
Loosely assemble Nuts (A) and (B) on Lower Rod (C).

2.
Set Transmission Lever (D) in drive position.
NOTE:
Obtain drive position by moving Trans-

mission Lever counter-clockwise to low detent,

then clockwise one detent position to drive.

3.
Set Control Pawl Lever Rod (E) in Neutral or drive

notch of Detent (F). See View A.

4.
Apply load in direction of Arrow (Y) on Actuating

Lever (G) until pawl Rod comes in contact with

Detent at Contact Point (Z). See View A.

5. Place a 7/64" Spacer (H) between Nut (A) and Swivel

(J),
run Nut (A) until it touches spacer. Remove

Spacer and apply load in the direction on Arrow (X)

until it touches Nut (A). Tighten Nut (B) against

Swivel and lock Swivel between Nuts (A) and (B).

See View B.

Chevelle Linkage Adjustment (Fig. 7PG)

1.
Assemble Nuts (A) and (B) on Lower Rod (C) loosely.

2.
Set Transmission Lever (D) in drive position.

NOTE:
Obrain drive position by moving Trans-

CHEVROLET CHASSIS SERVICE MANUAL

CLUTCH AND TRANSMISSIONS
7*30

V-8 Models-With Uni-Directional Linkage

1.
Remove air cleaner.

2.
Disconnect accelerator linkage at carburetor.

3.
Disconnect accelerator return and TV rod return

springs.

4.
With right hand, pull TV upper rod forward until

transmission is through detent. With left hand, open

carburetor to wide open throttle position. Carbure-

tor must reach wide open throttle position at the

same time the ball stud contacts end of slot in upper

TV rod.

5. Adjust swivel on end of upper TV rod to obtain set-

ting described in Step 4. Allowable tolerance is

approximately 1/32".

6. Connect and adjust accelerator linkage as described

in Section 6.

7. Check for throttle linkage freedom.

Neutral Safety Switch Adjustment

The adjustment at the neutral safety switch is de-

scribed in the Electrical Section 12.

Throttle Return Check Valve (Dashpot) Adjustment

The adjustment of the throttle return check valve is

described in Section 6M for each carburetor installation.
Fig.
12PG - Floor Mounted Control Lever and

Bracket Assembly (Chevrolet Shown)

COMPONENT PARTS REPLACEMENT

TRANSMISSION REPLACEMENT (EXC. CORVETTE)

Removal

1.
Raise car on hoist (preferably) or on stand jack and

remove oil pan drain plug to drain oil.

NOTE:
If desired, the oil may be drained after

transmission removal.

2.
Disconnect the oil cooler lines (external cooled

models), vacuum modulator line and the speedometer

drive cable fitting at the transmission. Tie lines

out of the way.

3.
Disconnect manual and TV control lever rods from

transmission.

4.
Disconnect propeller shaft from transmission.

5. Install suitable transmission lift equipment to jack

or other lifting device and attach on transmission.

6. Disconnect engine rear mount on transmission ex-

tension, then disconnect the transmission support

crossmember and slide rearward.

7. Remove converter underpan, scribe flywheel-con-

verter relationship for assembly, then remove the

flywheel-to-converter attaching bolts.

NOTE:
The "light" side of the converter is

denoted by a "blue" stripe painted across the

ends of the converter cover and housing. This

marking should be aligned as closely as possible

with the "white" stripe painted on the. engine

side of the flywheel outer rim (heavy side of

engine) to maintain balance.

8. Support engine at the oil pan rail with a jack or other

suitable brace capable of supporting the engine

weight when the transmission is removed.
9. Lower the rear of the transmission slightly so that

the upper transmission housing-to-engine attaching

bolts can be reached using a universal socket and a

long extension. Remove upper bolts.

CAUTION: Oh V-8 engines, care must be taken

not to lower rear of transmission too far as the

distributor housing may be forced against the

dash causing damage to the distributor. It is

best to have an assistant observe clearance of

all upper engine components while the trans-

mission rear end is being lowered.

10.
Remove remainder of transmission housing-to-

engine attaching bolts.

11.
Remove the transmission by moving it slightly to the

rear and downward, then remove from beneath the

car and transfer to a work bench.

NOTE:
Observe converter when moving the

transmission rearward. If it does not move

with the transmission, pry it free of flywheel

before proceeding.

CAUTION: Keep front of transmission upward

to prevent the converter from falling out. Install

converter Tool J-9549 (or a similar tool con-

structed as shown in Figure 13PG, or, in an

emergency, a length of strong wire may be used)

immediately after removal from the engine.

Installation

NOTE:
The "light" side, of the converter is

denoted by a "blue" stripe painted across the

ends of the converter cover and housing. This

marking should be aligned as closely as possible

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