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 7-13
PULL-IN
WINDING
li
HOLD-IN
WINDING
Fig.
4B -
Overdrive Electrical Circuit Wiring Diagram
ELECTRICAL
Any one of the following general complaints may be due
to electrical trouble in the overdrive circuit.
1.
Does not engage.
2.
Does not release.
3.
Does not kickdown from overdrive.
These troubles may be traced and remedied as de-
scribed in the following paragraphs.
1.
Does not engage
a. With the ignition switch on, ground the "KD" ter-
minal of the solenoid relay with a jumper lead.
If the solenoid clicks, the relay and solenoid cir-
cuits are in operating condition. If no click is
heard in the relay, check the fuse and replace if
defective.
b.
If the fuse is good, use a second jumper lead to
connect the "SOL" and "BAT" terminals of the
relay. If a click is now heard in the solenoid, the
relay is probably at fault and should be repaired
or replaced.
c. If the solenoid does not click in Step b, check the
wiring to the No. 4 terminal of the solenoid and
replace if necessary. If the wiring is not defec-
tive,
the trouble is probably in the solenoid. Re-
move the solenoid cover, examine the solenoid
contacts in series with the pull-in winding and
clean if necessary. Test again for clicks, as in
Step b, after replacing solenoid cover and lead
wires.
Replace the solenoid if trouble has not
been corrected.
d. If the relay and solenoid circuits are in good con-
dition as determined in Step a, leave the ignition
switch on and make sure the manual control knob
is in the overdrive position. Ground one and then
the other of the two terminals next to the stem of
the kickdown switch (identified as "SW" and
?fREL"). K the solenoid clicks when one terminal
is grounded but not the other, replace the switch.
If the solenoid does not click when either of the
terminals is grounded, check the wiring between
the relay and the kickdown switch and replace if
defective.
e. If the solenoid clicks as each terminal is grounded
in Step d, ground the governor switch terminal.
If the solenoid clicks, the governor switch may be
defective. If the solenoid does not click, check
the wiring between the kickdown and governor
switches and replace if necessary.
2.
Does not release
a. Remove the connection to the "KD" terminal of
the relay. If this release overdrive, look for a
grounded control circuit between the relay and
governor switch.
b.
If the overdrive is not released in Step a, dis-
connect the lead to the "SOL" terminal of relay.
If this releases the overdrive, replace the relay.
3.
Does not kickdown from overdrive
a. With the engine running, connect a jumper lead
between the No. 6 terminal of the solenoid and
ground. Operate the kickdown switch by hand.
This should stop the engine. If it does, the sole-
noid is probably defective and it should be checked
for dirty ground-out contacts or other defects
within the ground-out circuit of the solenoid (fig.
4B).
Clean the contacts or replace the contact
plate as required.
b.
If the engine does not stop in Step a, ground one
and then the other of the two terminals (Identified
as "IGN" and "SOL") farthest from the sfem of
the kickdown switch. The engine should stop when
one of the two terminals (IGN) is grounded. If
the engine does not stop when the terminal is
grounded, the wiring or connections to the switch
between the switch and coil are defective. When
the btlier terminal (SOL) is grounded, the engine
should stop when the kickdown switch is operated.
If the engine does not stop when the kickdown
switch is operated with the second terminal
grounded, the kickdown switch is defective. If
the trouble is in the kickdown switch, adjust the
linkage to give more travel of the switch rod.
If this does not correct the trouble, replace the
kickdown switch.
If the kickdown switch operates as it should,
check for an open circuit in the wiring between
the kickdown switch and the No. 6 terminal of the
solenoid.
c. If the trouble is not located by the above checks,
the upper contacts of the kickdown switch may not
be opening. To check for this condition, ground
the overdrive control circuit at the governor
switch. This should cause the solenoid to click.
Operate the kickdown switch by hand. This should
cause a second click as the solenoid releases.
If there is no second click, adjust the linkage to
give more travel of the switch rod. If this does
not correct the trouble, replace the kickdown
switch.
CHEVROLET CHASSIS SERVICE MANUAL
CLUTCH AND TRANSMISSIONS 7-14
SPEED HEAVY DUTY TRANSMISSION
(WARNER MODEL T 16)
INDEX
General Description ......
Maintenance and Adjustments
Shift Linkage Adjustment
Side Cover ........
Removal .........
Disassembly
7-14
7-14
7-14
7-14
7-14
7-14
Assembly 7-14
Installation • 7-15
Other Maintenance
&
Adjustment
Operations See 3-Speed Saginaw Section
Transmission Replacement . . . See 3-Speed Saginaw Section
GENERAL DESCRIPTION
The Borg-Warner heavy duty three speed fully syn-
chronized (all forward gears) transmission incorporates
helical gears throughout specially designed to provide
high torque capacity, and gear teeth proportion to operate
at high speeds with neither excessive heat generation nor
excessive frictional losses. Shafts, bearings, high ca-
pacity clutches and other precision parts are held to
close limits providing proper clearances necessary for
durability during extended heavy usage.
The main drive gear is supported by a heavy duty 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 heavy duty ball bearing mounted in the
front of the extension housing.
The countergear is carried on a double 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. An 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 reverse idler gear is carried on 25
roller bearings while thrust is taken on thrust washers
located between the ends of the gear and the thrust bosses
of the case.
Gear shifting is manual through shift control rods from
the shifter tube in the mast jacket to the rearward shift
lever of the side cover assembly for first and reverse
gear; and through a cross shaft assembly attached to the
forward side cover lever for second and third gear. All
three forward gears are fully synchronized. The syn-
chronizer 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. The transmission may be used as an aid
in deceleration by downshifting in sequence without
double-clutching or any gear clashing. Reverse is not
synchronized, however, it is a helical gear to insure
quiet operation.
MAINTENANCE AND ADJUSTMENTS
Refer to similar procedures under the 3-speed Saginaw
Transmission Section for—Column Mounted Shift Linkage
Adjustment, Speedometer Driven Gear and Oil Seal Re-
placement, Extension Oil Seal Replacement and Trans-
mission Replacement. ~~
Camaro and Corvette Floor Shift Linkage Adjustment
(Fig.
lc)
1.
Set Lever (L), (K) in neutral position.
2.
Move Lever Assembly (A) and Levers (C), (D) to
neutral position and insert Locating Gauge (B) into
control Lever Bracket Assembly.
3.,
Install Rod (H) with Retainer (M) on Lever (L).
4.
With two Jam Nuts (G), (E) and Swivel (F) loose on
Rod (H) insert and attach Swivel with Retainer (N)
to Lever (D).
5.
Repeat steps 3 and 4 for Rod (J) and Levers (C
&
K).
6. Remove' Locating Gauge and check shift to insure
proper operation.
SIDE COVER ASSEMBLY
Removal
1.
Drain transmission and disconnect control rod and
cross shaft from side cover levers. *
2.
Remove nine cap screws securing the transmission
side cover assembly to transmission, case and re-
move cover assembly, shifting forks, and gasket.
Disassembly (Fig. 2C) '
1.
Remove shifting forks from shift lever assemblies.
2.
Remove nut and lock washer from each shift lever
shaft.
3.
Remove outer shift levers and lightly tap shift lever
shafts from assembly.
4.
Remove two steel balls, poppet spring, interlock pin
and interlock sleeve from cover.
5.
Remove "O" ring seals from shift lever shafts.
Assembly (Fig. 2C)
1.
Install new "O" ring seals to shift lever shafts.
2.
Install low and reverse shifter shaft and plate as-
sembly to cover.
3.
Place shifter shaft and plate assembly in neutral po-
sition, middle detent, and install interlock sleeve,
ball, poppet spring and interlock pin.
4.
Install remaining poppet ball and then install second
and third shifter shaft and plate assembly.
NOTE: Installation is easiest if shifter shaft
and plate assembly passes over ball in its neu-
tral position.
5.
Check clearance between end of interlock sleeve and
shifter shaft and plate cams when one plate is in
neutral and the other is shifted into gear position.
CHEVROLET CHASSIS SERVICE MANUAL
CLUTCH AND TRANSMISSIONS 7-16
FOUR-SPEED TRANSMISSION (MUNCIE)
INDEX
Page
General Description 7-16
Maintenance and Adjustments 7-16
Shift Linkage Adjustment 7-16
Gearshift Lever Reverse Blocker Cable 7-17
Replacement . 7-17
Adjustment 7-17
Speedometer Driven Gear and Oil Seal 7-19
Replacement 7-19
Transmission Side Cover 7-19
Removal 7-19
Page
Disassembly 7-19
Assembly 7-19
Installation . 7-19
Extension Oil Seal ......... 7-19
Replacement 7-19
Component Parts Replacement 7-20
Transmission Replacement 7-20
Removal from Vehicle , 7-20
. Installation in Vehicle . . . 7-20
GENERAL DESCRIPTION
The four-speed synchromesh transmission incorpo-
rates helical gears throughout specially designed to pro-
vide high torque capacity without additional weight, and
gear teeth proportioned to operate at high speeds with
neither excessive heat generation nor excessive fric-
tional losses. Shafts, bearings, high capacity clutches
and other precision parts are held to close limits, pro-
viding proper clearances necessary for durability during
extended heavy usage.
The main drive gear is supported by a heavy-duty 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 heavy-duty ball bearing mounted at the
rear end of the transmission case in a retainer casing.
The counter gear is carried on a double 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.
The two-piece reverse idler gear is carried on bronze
bushings while thrust is taken on thrust washers located
between the front of the gear and the back of the reverse
idler thrust boss and between the rear of the gear and the
reverse idler shaft boss in the case extension.
Gearshifting is manual through shift control rods to the
transmission cover shifter levers for first through fourth
gears,
and to the reverse lever located in the case ex-
tension. The shifter lever to the rear of the transmis-
sion cover controls first and second gears while the
lever to the front controls third and fourth gears. All
four forward gears are fully synchronized. The trans-
mission may be used as an aid in deceleration by down-
shifting in sequence without double clutching. Reverse is
not synchronized, however, it is a helical gear to insure
quiet operation.
MAINTENANCE AND ADJUSTMENTS
SHIFT LINKAGE ADJUSTMENT (EXC. CORVETTE
AND CAMARO) (Fig. 1m)
1.
Set Transmission Levers (M), (P) and (S) in neutral
detent position.
2.
Move Shift Lever (A) to neutral detent position and
insert a Locating Gauge (1/8" thick by 41/64" (.646)
wide and 3" long) (B) into Control Lever Bracket
Assembly slot.
3.
Install Rod (V) with retainer on Lever (D).
4.
Maintaining Lever (D) against Locating Gauge, ad-
just Clevis (T) at Lever (S) until clevis pin freely
passes through holes in Clevis and Lever.
5. Install clevis pin, washer, and cotter pin. Tighten
Jam Nut (U) against Clevis.
6. Install Rod (H) with retainer on Lever (W).
7. With Jam Nuts (J) and (L) and Swivel (K) loose on
Rod (H), insert and attach Swivel with washer and
retainer to Lever (M).
8. Maintaining Lever (W) against Locating Gauge (B)
and while holding Swivel (K), run Jam Nut (J) against
Swivel until Nut contacts Swivel. Then tighten Jam
Nut (L) against Swivel.
9. Install Rod (R) with retainer on Lever (P).
10.
With Jam Nuts (E) and (G) and Swivel (F) loose on
Rod (R), insert and attach Swivel with retainer to
Lever (C).
11.
Maintaining Lever (C) against Locating Gauge (B) and
while holding Swivel (F), run Jam Nut (G) against
Swivel until Nut contacts Swivel. Then tighten Jam
Nut (E) against Swivel.
12.
Remove Locating Gauge and check shifts to insure
proper operation. Readjust clevis and swivels if
necessary.
NOTE:
Control rods may be attached to trans-
mission shift lever lower holes, to reduce shift
lever travel, for a "faster shift" adjustment op-
tion.
Increased shifting effort is required when
control rods are installed in this "short throw"
position.
CORVETTE AND CAMARO SHIFT LINKAGE
ADJUSTMENT (Fig. 2M)
1.
Set Transmission Shift Levers in neutral position.
2.
Move Shift Lever (A) to neutral position and insert
Locating Gauge (C) into control Lever Bracket As-
sembly (B).
3.
Install Reverse Rod (J) with Retainer on Lever (O).
4.
With two Jam Nuts and Swivel loose on Rod (J) insert
and attach Swivel with Retainer to Lever (D).
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*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