SECTION 7
CLUTCH AND TRANSMISSIONS
CONTENTS OF THIS SECTION
Clutch
Three-Speed . . .
Overdrive
Three-Speed, (Warner T-16)
Four-Speed (Muncie) . . . .
Page
7-1
7-6
7-9
7-14
7-16
CLUTCH
Page
Four-Speed (Saginaw) 7-20
Powerglide 7-23
Turbo Hydra-Matic 7-36
Special Tools 7-43
INDEX
General Description
Maintenance and Adjustments
Linkage Inspection
Clutch Linkage Adjustment
Component Parts Replacement
Clutch Assembly ......
Removal from Vehicle .
Page
7-1
7-1
7-1
7-2
7-3
7-3
7-3
Installation in Vehicle
Clutch Pedal ..'....,
Clutch Cross Shaft . . .
Removal.......
Repairs
Installation .....
Page
7-4
7-4
7-4
7-4
7-4
7-4
GENERAL DESCRIPTION
A diaphragm spring-type clutch assembly is used with
manual transmissions.
The clutch assembly is enclosed in a 360° bell housing
which must be removed to gain access to the clutch.
V-8 engines (equipped with a 4 speed transmission)
use a bent-finger, centrifugal diaphragm type clutch as-
sembly. All its integral release fingers are bent back to
gain a centrifugal boost and to insure quick re engagement
at high engine speeds.
This type of clutch has the advantages of increasing
pressure plate load as the driven plate wears, and of low
pedal effort with high plate loads without requiring over-
center booster springs on the clutch linkage.
The pressure plate is a high tensile strength iron de-
signed for maximum speed conditions.
The clutch release bearing (fig. 4), used with the bent
finger diaphragm clutch, has an overall length of approxi-
mately
1-1/4".
The longer bearing, used with the straight
diaphragm, will cause inability to obtain free pedal travel,
especially as the clutch wears, resulting in slippage and
rapid wear.
DO
NOT INTERCHANGE!
The clutch is operated by conventional linkage consist-
ing of two groups, upper linkage and lower linkage.
The return spring pre-loads clutch linkage, removing
looseness due to wear. The clutch free pedal travel,
therefore, will increase with linkage wear and decrease
with driven disc wear, and free travel felt at pedal is
throwout bearing lash.
MAINTENANCE AND ADJUSTMENTS
LINKAGE INSPECTION
There are several things which affect good clutch op-
eration. Therefore, it is necessary, before performing
any major clutch operations, to make preliminary in-
spections to determine whether trouble is actually in the
clutch.
Check the clutch linkage to be sure the clutch releases
fully as follows:
1.
With engine running, hold the clutch pedal approxi-
mately 1/2" from floor mat and move shift lever be-
tween first and reverse several times. If this can be
done smoothly, the clutch is fully releasing. If shift
is not smooth, clutch is not fully releasing and ad-
justment is necessary.
2.
Check clutch pedal bushings for sticking or excessive
wear.
3.
Check fork for proper installation on ball stud. Lack
of lubrication on fork can cause fork to be pulled off
the ball.
4.
Check for bent, cracked or damaged cross shaft
levers or support bracket.
5.
Loose or damaged engine mounts may aUiow the en-
gine to shift its position causing a bind on clutch
linkage at the cross shaft. Check to be sure there is
Fig.
1 - Chevrolet Clutch Pedal Free Travel Adjustment
CHEVROLET CHASSIS SERVICE MANUAL
CLUTCH AND TRANSMISSIONS 7-4
5.
Install Tool J-5824 to support the clutch assembly
during removal.
NOTE: Look for "X" mark on flywheel and on
clutch cover. If MX" mark is not evident, prick
punch marks on flywheel and clutch cover for
indexing purposes during installation.
6. Loosen the clutch-to-flywheel attaching bolts evenly
1 turn at a time until spring pressure is released,
then remove the bolts, and remove clutch assembly.
Installation to Vehicle
Clean pressure plate and flywheel face. (They should
be free of oil, grease, metal deposits or burned spots).
1.
Position the clutch disc and pressure plate in relar
tive installed position and support them with align-
ment Tool J-5824.
NOTE: The driven disc on the 4 and 6 cylinder
engines is installed with the damfper springs to
the flywheel side; the V-8 is opposite, however,
THE GREASE SLINGER IS ALWAYS ON THE
TRANSMISSION SIDE.
2.
Turn clutch assembly until "X" mark on cover lines
up with "X" mark oh flywheel, then align cover bolt
holes to nearest flywheel holes.
3.
Install a bolt in every hole and tighten down evenly
and gradually until tight (to avoid possible clutch
distortion).
NOTE: Cover loads are as high as 1-1/4 tons.
4.
Remove pilot tool.
5.
Unhook clutch fork and lubricate ball socket and fork
fingers at release bearing end with a high melting
point grease such as graphite and reinstall fork on
ball stud. On Corvette models use Moly Grease.
6. Lubricate the recess on the inside of throwout bear-
ing collar and the throwout fork groove with a light
coat of graphite grease (fig. 4). On Corvette models
use Moly Grease.
7.
Install clutch fork and dust boot into clutch housing
and install throwout bearing to the throwout fork, then
install flywheel housing.
8. Install transmission as outlined in transmission
section.
9. Connect fork push rod and spring.
10.
Adjust shift linkage as outlined in transmission
section.
11.
Perform linkage adjustment for pedal free play and
check clutch release position.
CLUTCH PEDAL
The clutch pedal is the pendant-type hung from a sup-
Fig. 5 - Release Bearing Lubrication and Comparison
port brace common to the brake pedal and must be re-
moved to remove brake pedal. Refer to Section 5 for
brake and clutch pedal service procedure.
CLUTCH CROSS SHAFT (Figs. 6, 7 & 8)
Removal
1.
Remove linkage return and lower linkage springs and
disconnect clutch pedal and fork push rods from re-
spective cross shaft levers.
2.
Loosen outboard ball stud nut and slide stud out of
bracket slot.
3.
Move cross shaft outboard, and as required to clear
inboard ball stud, then merely lift out to remove
from vehicle.
Repairs
The cross shaft has nylon ball stud seats which should
be inspected for wear or damage. Also check condition
of engine bracket ball stud assembly and special anti-
rattle "O" ring. Figures 6, .7
&
8 show component parts
of cross shaft. Replace parts as necessary based on wear
or damage. Lubricate ball studs and seats with graphite
grease before reassembly.
Installation
1.
Reverse removal procedure to install.
2.
Adjust clutch linkage as previously outlined.
CHEVROLET CHASSIS SERVICE MANUAL
CLUTCH AND TRANSMISSIONS 7-7
MAINTENANCE AND ADJUSTMENTS
CHEVROLET, CHEVELLE, CHEVY II, CAMARO,
SHIFT LINKAGE ADJUSTMENT
In cases where the gearshift linkage has been discon-
nected, it should be adjusted as follows:
1.
Move both transmission shift levers until transmis-
sion is in neutral. Neutral detents in transmission
cover must both be engaged to make this adjustment
correctly. (To check, start engine with clutch dis-
engaged, and release clutch slowly.)
2.
Move selector lever to neutral position. Align first
and reverse tube lever with the second and third
shifter tube lever on the mast jacket. This may be
done by having an assistant hold the mast .jacket shift
levers aligned in neutral position or use a simple
gauge or pin to align these levers in neutral.
3.
Make necessary adjustment to align shift control
rods and transmission levers in neutral position.
Move selector lever through all positions to check ad-
justment and to insure over-travel in all positions.
FLOOR SHIFT LINKAGE ADJUSTMENT
1.
Set Transmission Levers (K) and (L) in neutral de-
tent position.
2.
Move Transmission Control Lever (A) to neutral de-
tent and insert Locating Pin (D) into notch of Lever
and Bracket Assembly.
3.
Install Nut (N) and Clevis (M) on Rod (J) loosely,
attach Rod to Lever (B) and secure with retainer.
4.
With Lever (B) against Locating Pin, adjust Clevis
at Lever (L) until Clevis pin passes freely through
holes and secure with washer and cotter pin. Tighten
Nut (N).
5.
Install Nuts (E) and (G) and Swivel (F) loosely on Rod
(H),
attach Rod to Lever (K) and secure with retainer.
6. With Lever (C) against Locating Pin, attach Swivel to
lever and secure with retainer. iRun Nut (G) against
Swivel, then tighten Nut (E) against Swivel.
7.
Remove Locating Pin and check shifts to insure
proper operation. Readjust clevis and swivel if nec-
essary.
LEVER (A)
LEVER (L) CLEVIS (M)-NUT (N
LEVER (C)
ROD(J).
" - -
LEVER (K) ROD (H)^ NUT '(G) SWIVEL (F) ^NUT (E)
SHIFT CONTROL LEVER AND BRACKET ASSEMBLY
If disassembly of this control lever and bracket assem-
bly is necessary refer to Figure 2A for parts breakdown
and relative positioning for assembly.
SPEEDOMETER DRIVEN GEAR
Disconnect speedometer cable, remove lock plate to ex-
tension bolt and lock washer and remove lock plate. In-
sert screwdriver in lock plate slot in fitting and pry fitting
gear and shaft from extension. Pry "O" ring from groove
in fitting.
Install new "OM ring in groove in fitting. Coat "O" ring
and driven gear shaft with transmission lubricant and in-
sert shaft.
Hold the assembly so slot in fitting is toward lock plate
boss on extension and install in extension. Push fitting
into extension until lock plate can be inserted in groove
and attach to extension.
EXTENSION OIL SEAL REPLACEMENT
.1.
Remove propeller shaft as outlined in Section 4 and
disconnect any necessary items to obtain clearance.
2.
Pry seal out of extension.
3.
Wash counterbore with cleaning solvent and inspect
for damage.
4.
Prelubricate between sealing lips and coat new seal
O.D. with Permatex or equivalent and start straight
in bore in case extension. Using Tool J-5154, tap
seal into counterbore until flange bottoms against
extension.
Fig.
1A- Shift Linkage Adjustment (Typical)
Fig.
2A - Corvette 3 Speed Control Lever and Bracket Assembly
CHEVROLET CHASSIS SERVICE MANUAL
CLUTCH AND TRANSMISSIONS 7-9
6. Connect speedometer cable.
7. Install propeller shaft assembly.
8. Fill transmission with lubricant specified in Section
O.
CORVETTE TRANSMISSION REPLACEMENT
, 1. Disconnect battery ground cable.
2.
Pisassemble transmission shift control lever by un-
screwing ball from lever, lifting out
"T"
handle re-
turn spring and "T" handle, then remove the anti-
rattle bushings.
3.
Raise front and rear of vehicle.
4.
Insert a block of wood between the top of the dif-
ferential carrier housing and the underbody (to pre-
vent upward travel of the carrier when the carrier
front support is disconnected).
5. Disconnect the differential carrier front supportfrom
its frame bracket, by removing the nut on the under-
side of the biscuit mount.
6. Pry the carrier downward to relieve load while re-
moving the two center mounting bolts from the car-
rier front support. (To pry carrier downward insert
crowfoot end of a pry bar through the opening in the
carrier front support, hooking end of bar over top of
the center mounting bolt pad cast in the underside of
the carrier.)
7. Pivot carrier support downward for access to prop
shaft "U" joint.
8.
.
Disconnect prop shaft front and then rear "U" bolts.
9. Disconnect parking brake cable from ball socket at
idler lever located near center of underbody.
10.
Remove prop shaft by moving shaft forward.
11.
Remove heat deflectors from the right and left ex-
haust pipe.
12.
Remove left bank exhaust pipe.
13.
Remove right bank exhaust pipe and heat riser.
14.
Disassemble the transmission mount, as follows:
a. Remove the two bolts that attach rear mount
cushion to the rear mount bracket.
b.
Support engine under oil pan and raise engine to
remove load from rear mount cushion.
CAUTION: To avoid damage to oil pan, a suit-
able wide base, heavy wood platform should be
placed between the jack pad and the oil pan.
c. Remove the three transmission mount bracket-
to-
crossm ember bolts and remove mount bracket.
d. Remove the two bolts from mount pad to trans-
mission case and remove rubber mount cushion
and exhaust pipe "yoke".
15.
Disconnect transmission linkage by removing the
shift levers at the transmission side cover.
16.
Disconnect speedo cable at transmission extension.
17.
Remove transmission output shaft slip yoke.
NOTE:
The yoke is removed to avoid tearing
the heat reflecting pad on the underbody, when
the transmission is being removed.
18.
Remove two bolts to disconnect the transmission
gearshift control lever and bracket assembly from
its adapter plate on side of transmission. Lower
transmission assembly from the vehicle, letting the
gearshift lever slide down and through the dust boot
in the console.
19.
Remove transmission-to-clutch housing attaching
bolts.
20.
Slide transmission assembly rearward from clutch
and rotate transmission for access to the three flat
head machine screws in the control lever bracket
adapter plate. Remove adapter plate. Rotate trans-
mission back to the upright position.
21.
To allow room for transmission removal slowly
lower the rear of engine until the tachometer drive
cable at the distributor just clears the horizontal
ledge across the front of dash.
CAUTION: The tachometer cable can be easily
damaged by heavy contact with the dash. Slide
transmission rearward out of the clutch, then
tip front end of transmission downward and
lower the assembly from vehicle.
22.
Reinstall transmission assembly by performing above
steps in reverse order.
TRANSMISSION OVERDRIVE
INDEX
Page
General
Description 7-10
Maintenance
and Adjustments 7—10
Governor
Switch and Pinion .............. 7-10
Sun
Gear Solenoid Oil Seal and Control
Cable
Bracket 7-10
Case
Rear Oil Seal 7-10
Removal
7-10
Installation
. . . . . 7-10
Control
Shaft Lever and Oil Seal 7-10
Speedometer
Driven Gear 7-10
Electrical
Unit Checks 7-11
Overdrive
Relay . 7-11
Page
Air
Gap 7-11
Point
Opening 7-11
Closing
Voltage 7-11
Solenoid
. 7-11
Closing
Coil 7-11
Engaging
Spring . - 7-11
Ignition
Grounding Contact . 7-11
Governor
Switch 7-11
Kickdown
Switch 7-11
Diagnosis
- Overdrive 7-12
Mechanical
. 7-12
Electrical
7-13
CHEVROLET CHASSIS SERVICE MANUAL
CLUTCH AND TRANSMISSIONS 7-10 ,
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