fluid rear CHEVROLET CAMARO 1967 1.G Chassis User Guide

BRAKES
5-3

PRIMARY

SHOE

PAWL
WIRE LINK

OVERRIDE

LEVER

VERRIDE

SPRING

RETURN

SPRING

STAR
WHEEL

Fig.
3—Camaro
Pressure
Regulator
Valve
Fig.
4-Self-Adjusting
Brake

MAINTENANCE AND ADJUSTMENTS

In any service operation it is extremely important

that absolute cleanliness be observed. Any foreign matter

in the hydraulic system will tend to clog the lines, ruin

the rubber cups of the main and wheel cylinders and

cause inefficient operation or even failure of the braking

system. Dirt or grease on a brake lining may cause

that brake to grab first on brake application and fade

out on heavy brake application.

The split system consists basically of two separate

brake systems. When a failure is encountered on either,

the other is adequate to stop the vehicle. If one system

is not functioning, it is normal for the brake pedal lash

and pedal effort to substantially increase. This occurs

because of the design of the master cylinder which

incorporates ah actuating piston for each system. When

the rear system loses fluid and takes in air, its piston

will bottom against the front piston. When the front

system loses fluid and takes in air, its piston will

bottom on the end of the main cylinders body. The loss

of fluid in one of the systems causes an uneven hydraulic

pressure balance between the front and rear systems.

The brake pipe distribution and switch assembly, near

the main cylinder, detects the loss of pressure and il-

luminates the brake alarm indicator light on the instru-

ment panel. The pressure loss is felt at the brake pedal

by an apparent lack of brakes for most of the brake

travel and then, when failed chamber is bottomed, the

pedal will harden.

HYDRAULIC BRAKE FLUID

Use GM Hydraulic Brake Fluid, Supreme No. 11 or

equivalent when servicing brakes. This brake fluid is

satisfactory for any climate and has all the qualities

necessary for proper operation, such as a high boiling

point to prevent vapor lock and the ability to remain

fluid at low temperatures.
In the event that improper fluid has entered the system,

it will be necessary to service the system as follows:

1.
Drain the entire system.

2.
Thoroughly flush the system with clean alcohol,

188
proof,
or a hydraulic system cleaning fluid

such as "Declene".

3.
Replace all rubber parts of the system, including

brake hoses.

4.
Refill the system.

5. Bleed the system.

BLEEDING HYDRAULIC SYSTEM

The hydraulic brake system must be bled whenever

any line has been disconnected or air has in some way

entered the system. A ''spongy" pedal feeling when the

brakes are applied may indicate presence of air in the

system. The system must be absolutely free of air at

all times. Bleeding should be done on the longest line

first; the proper sequence to follow is left rear, right

rear, right front, and left front (fig. 5). Bleeding of

brake system may be performed by one of two methods—

either pressure or manual.

PRESSURE
BLEEDING

1.
Clean all dirt from top of main cylinder and remove

cylinder cover and rubber diaphragm.

2.
Reduce fluid level in main cylinder until reservoirs

are approximately half full.

NOTE:
Make sure brake fluid in bleeder equip-

ment is at operating level and that the. equipment

is capable of exerting 30 to 50 lbs. hydraulic

pressure on the brake system.

3.
Install brake bleeder adapter J-22489 (fig. 6) on

main cylinder. Connect hose from bleeder equipment

to bleeder adapter and open release valve on bleeder

equipment.

CHEVROLET CHASSIS SERVICE MANUAL

BRAKES 5-16

6Y. Adjust clutch pedal travel as outlined in

Section 7.

SHOES AND LININGS

Organic Linings

NOTE:
If brake drums are worn severely, it

may be necessary to retract the adjusting screw.

To gain access to the adjusting screw star

wheel, knock out the lanced area in the web of

the brake drum using a chisel or similar tool.

Release the actuator from the star wheel by

lifting with a small screw driver and back off

the star wheel with a second screw driver (press

down on the handle to retract shoes).

CAUTION: After knocking out the metal, be

sure to remove it from the inside of the drum .

and clean all metal from the brake compartment.

A new hole cover must be installed when drum

is reinstalled.

Removal

1.
Raise the vehicle and plate on jack stands.

2.
Loosen check nuts at parking brake equalizer suffi-

ciently to remove, all tension from brake cable.

3.
Remove brake drums.

NOTE:
Since there are wheel cylinder piston

stops to prevent pistons from leaving cylinders,

it is not necessary to install wheel cylinder

clamps when brake shoes are removed; however,

brake pedal must not be depressed while drums

are removed.

4.
Unhook brake shoe pull back springs from anchor

pin and link end, using Tool J-8049 (fig. 27).

5. Remove the actuator return spring and link.

6. Remove hold-down pins and springs (fig. 28).

7. Remove the actuator assembly.
NOTE:
The actuator, pivot and override spring

are an assembly. It is not recommended that

they be disassembled for service purposes,

unless they are broken. It is much easier to

assemble and disassemble the brakes by leaving

them intact.

8. Separate the brake shoes by removing adjusting

screw and spring.

9. Remove parking brake lever from secondary brake

shoe (rear only).

Inspection

1.
Clean all dirt out of brake drum using care to avoid

getting dirt into front wheel bearings. Inspect drums

for roughness, scoring or out-of-round. Replace or

recondition drums as required.

2.
Inspect wheel bearings and oil seal, and replace

any necessary parts.

3.
On Chevrolet only:

Carefully pull lower edges of wheel cylinder boots

away from cylinders and note whether interior is

wet with brake fluid. Excessive fluid at this point

indicates leakage past piston cups and a need for

wheel cylinder overhaul or replacement.

NOTE:
A slight amount of fluid is nearly always

present and acts as lubricant for the piston.

4.
Check cylinders with internal boots by carefully pull-

ing a small part of the boot out of the cylinder.

Note whether interior is wet with brake fluid. Ex-

cessive fluid at this point indicates leakage past

piston cups and a need for wheel cylinder overhaul

or replacement.

5. Check all brake flange plate attaching bolts to make

sure that they are tight. Clean all rust and dirt

from shoe contact faces on flange plate (fig. 29),

using fine emery cloth.

Installation

CAUTION: Make certain to install recom-

Fig.
27-Unhooking Pull Back Spring
Fig.
28—Removing Hold-Down Springs and Pins

CHEVROLET CHASSIS SERVICE MANUAL

BRAKES
5-24

DISC BRAKES

INDEX

Page

General Description
. 5-24

Maintenance
and
Adjustments
5-24

Bleeding Hydraulic System
5-24

Parking Brake Adjustment
-
Corvette
5-24

Component Replacement
and
Repairs
5-25
Page

Brake Shoes
. . . . . 5-25

Brake Caliper
5-26

Brake Disc
5-29

Main Cylinder.
5-30

Parking Brake Shoes
-
Corvette
5-30

GENERAL DESCRIPTION

Four wheel disc brakes
are
standard equipment
on

the
1967
Corvette,
as in 1966. The
Corvette
may
also

be equipped with heavy duty disc brakes which include

new front calipers, shoes, linings,
and
rear pressure

regulator valve. This heavy duty option
is
used
in

conjunction with
a
vacuum power unit. Front wheel disc

brakes
are
installed
as
optional equipment
on
Chevrolet,

Chevelle, Camaro,
and
Chevy
II
models.

The disc brake,
(fig. 35),
consists
of a
fixed caliper,

rotating disc, splash shield,
and
mounting bracket.
The

caliper assembly contains four pistons and two shoe
and

lining assemblies with
the
lining riveted
to the
steel

shoes.
A
seal
and
dust boot
are
installed
on
each piston,

with
a
piston spring
in the
caliper cylinder bore beneath

each piston.
A
retaining pin extends through each caliper

half
and
both shoes
to
hold
the
shoes and linings
in
posi-

tion
in the
caliper.
On
Corvette heavy duty disc brakes,

two retaining cotter pins
are
used
at
each end
of the

caliper
to
secure
the
shoes
and
linings. Machined
sur-

faces within
the
caliper prevent
the
shoe
and
lining
assembly from rotating with
the
brake disc when pres-

sure
is
applied.

The disc, which
has a
series
of air
vent louvers
to

provide cooling,
is
mounted
on the
front wheel-hub.

The caliper straddles
the
disc and mounts
on a
mounting

bracket attached
to the
steering knuckle with
two
bolts.

The Corvette heavy duty option includes
a
pressure

regulator valve mounted
in the
rear brake line just

below
the
main cylinder. Chevrolet, Chevelle, Camaro,

and Chevy
n
models with disc brakes have
a
pressure

regulator valve mounted
in the
front brake line just

below
the
main cylinder. The valve controls
the
hydraulic

pressure
to the
front
or
rear brakes,
as
applicable,

resulting,
in the
correct pressure balance between
the

front
and
rear hydraulic systems. This valve guards

against premature .lock-up
of
front
or
rear wheels when

brakes
are
applied.

Maintenance, adjustment,
and
service operations which

are
not
included
in
this section
are the
same
as for

the Duo-Servo type brakes.

MAINTENANCE
AND
ADJUSTMENTS

BLEEDING HYDRAULIC SYSTEM

The operation
of
bleeding
the
disc brake hydraulic

system
is the
same
as for
Duo-Servo system outlined

in
the
front
of
this section. Note
the
exceptions below

and refer
to
bleeding procedures under Duo-Servo

brakes.

1.
When pressure bleeding equipment
is
used,
the

correct pressure setting
for
bleeding disc brakes

is 10-2.0
lbs. on
Corvette,
and 40 lbs. on all
other

models.

2.
The
front calipers contain
one
bleeder valve.
The

rear calipers
on
Corvette contain two bleeder valves

(one inboard
and one
outboard) which necessitates

the removal
of the
rear wheels
for
bleeding.

3.
Tapping
the
caliper with
a
rawhide mallet
as the

fluid
is
flowing
out may
assist
in
obtaining
a
good

bleeding
job.

4.
On
Chevrolet, Chevelle, Camaro
and
Chevy
II, the

spring loaded
end of the
pressure regulator valve

(fig.
36)
must
be
held (valve
in
open position) while

bleeding. This
is
done
by
depressing
and
holding

in
the
plunger
in the
end
of
the valve either
by
hand,

by taping,
or by
clamping.
PARKING BRAKE-CORVETTE

Adjustment

1.
Raise rear
end of
vehicle
and
place
on
jack stands.

2.
Remove rear wheels.

3/
Loosen brake cables
at the
equalizer until
the
park-

ing brake levers move freely
to the "off"
position

with slack
in the
cables.

4.
Turn
the
disc until
the
adjusting screw can
be
seen

through
the
hole
in the
disc.

5. Insert
an
adjusting tool
or
screw driver through
the

hole
in the
disc
and
tighten
the
adjusting screw
by

moving your hand away from
the
floor
on
both
the

left and right sides
(fig. 37).

6. Tighten until
the
disc will
not
move, then back
off

ten
(10)
notches.

7. Apply
the
parking brake four
(4)
notches from inside

the
car.

8. Tighten
the
brake cables
at the
equalizer
to
produce

a light drag with
the
wheels mounted.

9. Fully release
the
parking brake handle
and
rotate

the rear wheels.
No
drag should be evident with
the

handle released.

CHEVROLET CHASSIS SERVICE MANUAL

BRAKES 5-26

PRESSURE

REGULATOR

VALVE

CHEVROLET
PRESSURE

REGULATOR

VALVE

CAMARO

Fig.
36—Pressure Regulator Valve—Chevrolet and Camaro Shown

install two retaining cotter pins, one at each end of

the caliper.)

8. Repeat above procedure at each wheel where shoes

are to be replaced.

9. Refill main cylinder to fluid level shown in Figure

8. If necessary, bleed brake system as outlined in

this section.

10.
Install wheels and lower vehicle.

BRAKE
CALIPER

Removal

1.
Raise vehicle and place on jackstands.
2.
Remove wheel.

3.
On front caliper, disconnect the brake hose at brake

line support bracket. On Corvette rear caliper,

disconnect the brake tubing from the inboard caliper.

Tape the open tube or line end to prevent foreign

matter from entering the system.

4.
Pull cotter pin from end of shoe assembly retaining

pin.
Remove the pin and shoe assembly from the

Fig.
37—Adjusting Parking Brake Shoes
Fig.
38—Replacing Shoe and Lining Assembly

CHEVROLET CHASSIS SERVICE MANUAL

BRAKES 5-28

Fig.
40—Installing Piston in Caliper Bore Using

Tool J-22591
Fig.
41—Installing Boot Seal in Caliper Bore

Using Tool J-22592

5.
Check the fit of the piston in the bore using a feeler

gage.
Clearance should be as follows:

2 1/16 inch Bore .0045 to .010

1 7/8 inch Bore .0045 to .010

1 3/8 inch Bore .0035 to .009

If the bore is not damaged, and the clearance exceeds

either of the upper limits, a new piston will be required.

Assembly

1.
Assemble the seal in the groove in the piston which

is closest to the flat end of the piston. The lip on

the seal must face toward the large end of the

piston. Be sure lips are in the piston groove and do

not extend over the step in the end of the groove.

2.
Place the spring in the bottom of the piston bore.

3.
Lubricate the seal with dean brake fluid.

4.
Install the piston assembly in the bore using appli-

cable piston rign compressor Tool J-22639, 22629

or 22591 as shown in Figure 40. Use care not to

damage the seal lip as piston is pressed past the

edge of the bore. .

5.
Assemble the boot in the groove of the piston closest

to the concave end of the piston. The fold in the boot

must face toward the end of the piston with the seal

on it.

6. Depress the pistons and check that they slide

smoothly into the bore until the end of the piston is

flush with the end of the bore. If not, re check piston

assembly and location of the piston spring and the

seal.

7.
Position applicable boot seal installer Tool J-22592,

J-22628, or J-22638 over the piston and seat the

steel boot retaining ring evenly in the counterbore

as shown in Figure 41. The boot retaining ring must

be flush or below the machined face of the caliper.

Any distortion or uneven seating could allow con-

taminating and corrosive elements to enter the bore.
8. Position the t:O}> rings in the small cavities around

the brake fluid transfer holes in both ends of the

outboard caliper halves. Lubricate the hex head

. bolts with Delco Brake Lube or clip in clean brake

fluid. Fit caliper halves together and secure with

bolts.
Refer to torque specifications in rear of

manual for correct torque valves.

Installation

1.
Carefully mount the assembled caliper over the edge

of the disc. Use a putty knife to depress pistons so

that the caliper can be lowered into position on the

disc (fig. 42). Use care to prevent damage to boots

• on the edge of the disc as the caliper is mounted.

2.
Secure the caliper to the mounting bracket with two

hex head bolts. Refer to torque specifications in

rear of manual for correct torque values.

CAUTION: If replacing old shoe assemblies,

be sure to get the shoes in the same position

from which they were removed. New shoe as-

semblies have an arrow printed on the back,

showing the direction of forward disc rotation.

3.
Install the shoe and lining assemblies as outlined in

this section.

4.
On Chevrolet and Corvette front calipers, place a

new copper gasket on the male end of the front

wheel brake hose. On all models, install brake hose

in the calipers. With the wheels straight ahead,

pass the female end of the brake hose through the

support bracket.

5.
Make sure the tube seat is clean and connect the

break line tube nut to the caliper. Tighten securely.

6. Allowing the hose to seek a normal position, without

twist, insert hex of the hose fitting into the 12-point

hole in the support bracket and secure it in place

with the "V"-shaped retainer. Turn the steering

geometry from lock to lock while observing the hose.

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 7-32

21.
Remove transmission output shaft slip yoke and in-

sert a plastic shipping plug in end of extension to

prevent spillage of transmission fluid.

NOTE:
The yoke is removed to avoid tearing

the heat reflecting pad on the underbbdy, when

the transmission is being removed.

22.
Remove bright metal ignition shielding from dis-

tributor area.

23.
Remove the transmission dip stick and tube

assembly.

24.
Disconnect transmission vacuum modulator line at

distributor advance line tee.

25.
Position transmission hoist under transmission and

attach safety chain to transmission.

26.
Remove transmission converter housing-to-engine

attaching foolts and slide transmission rearward.
NOTE:
Observe converter when moving trans-

mission rearward. If converter does not move

with the transmission, pry it free of flywheel

before proceeding.

27.
Install converter retaining strap.

28.
Lower and remove transmission from vehicle by

tilting the front down and to the right while inter-

mittently lowering the transmission to facilitate its

• removal.

29.
Reinstall transmission assembly by performing the

above steps in reverse order.

Bolt Torques

Transmission Case to Flywheel

Housing Bolts 35 ft. lbs.

Converter to Flywheel Bolts. . , . . 35 ft. lbs.

OTHER SERVICE OPERATIONS

Although certain operations, such as oil pan or gasket

replacement, valve body, governor, filler pipe "O" ring,

speedometer drive gear, case extension "0" ring and

rear oil seal, vacuum modulator, and servo cover or

gasket service may be performed from underneath the
vehicle without removing the Powerglide; their service

procedure is covered in the Passenger Overhaul Manual

and is not repeated here. Refer to the- Powerglide Sec-

tion of the Passenger Overhaul Manual for all other

service operations not covered here.

DIAGNOSIS

Proper operation of the Powerglide transmission may

be affected by a number of factors, all of which must be

considered when trouble in the unit is diagnosed.

Proper trouble diagnosis can only be accomplished

when performed in a thorough step by step procedure.

The following procedure has been devised and tested and

is recommended for all trouble diagnosis complaints and

if the service man will follow this checking procedure,

accurate and dependable diagnosis may be accomplished.

This will result in a savings of time, not only to the

service man, but to the customer as well.

WARMING UP TRANSMISSION

Before attempting to check and/or correct any com-

plaints on the Powerglide transmission it is absolutely

essential that the oil level be checked and corrected if

necessary. An oil level which is either too high or too

low can be the cause of a number of abnormal conditions

from excessive noise to slippage in all ranges.

It must be remembered that cold oil will slow up the

action of the hydraulic controls in the transmission. For

this reason a trouble or oil leak diagnosis should not be

attempted until the transmission has been warmed up by

either of the following procedures:

Shop Warm Up

1.
Connect tachometer to engine.

2.
Set parking brake tight and start engine.

3.
Place selector light in
"D"
(drive) range.

4.
Adjust carburetor idle speed adjusting screw to run

engine at approximately 750 rpm and operate in this

manner for two minutes. At the end of two minutes

of operation, the transmission will be sufficiently

warmed up for diagnosis purposes.
NOTE:
At this point, readjust the engine idle

speed to 450-475 rpm in
"D"
range.

Road Warm Up

Drive the car approximately 5 miles with frequent

starts and stops.

NOTE:
At this point, make sure the engine idle

speed is set to 450-475 rpm in
"D"
range.

CHECKING FLUID LEVEL AND CONDITION

After transmission has been warmed up, check the

fluid level with the engine idling, parking brake set and

control lever in "N" (neutral). If the fluid level is low,

add fluid to bring level up to the full mark on gauge rod,

CAUTION: If fluid level is too high, fluid may

be aerated by the planet carrier. Aerated fluid

will cause turbulence in the converter which will

result in lost power, lower stall speed and lower

pressures in control circuits. Lower fluid level

to full mark, then shut off engine to allow air

bubbles to work out of fluid.

When checking oil level, aburned smell and discolora-

tion indicate burned clutches or bands and the transmis-

sion will have to be removed.

MANUAL LINKAGE

Manual linkage adjustment and the associated neutral

safety switch are important from a safety standpoint.

The neutral safety switch should be adjusted so that the

engine will start in the Park and Neutral positions only.

With the selector lever in the Park position, the park-

ing pawl should freely engage and prevent the vehicle

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