1967 CHEVROLET CAMARO lock

ENGINE-ELECTRICAL 6Y-27

timing mark on pulley lines up with timing tab.

2.
Position distributor to opening in block in normal

installed attitude (fig. 15i), noting position of vacuum

control unit.

3.
Position rotor to point toward front of engine (with

distributor housing held in installed attitude), then

turn rotor counter-clockwise approximately 1/8 turn

more toward left cylinder bank and push distributor

down to engine camshaft. It may be necessary to ro-

tate rotor slightly until camshaft engagement is felt.

4.
While pressing firmly down on distributor housing,

kick starter over a few times to make sure oil pump

shaft is engaged. Install hold-down clamp and bolt

and snug up bolt.

5. Turn distributor body slightly until points just open

and tighten distributor clamp bolt.

6. Place distributor cap in position and check to see

that rotor lines up with terminal for No. 1 spark

plug.

7. Install cap, check all high tension wire connections

and connect spark plug wires if they have been re-

moved. It is important that the wires be installed in

their location in the supports.

NOTE:
The brackets are numbered to show the

correct installation. Wires must be installed as

indicated to prevent cross firing.

8. Connect vacuum line to distributor and distributor

primary wire to coil terminal.

9. Start engine and set timing as described under Turn-

Up in Section 6.

BREAKERLESS (MAGNETIC PULSE)

DISTRIBUTOR

REMOVAL (CORVETTE)

1.
If vehicle is equipped with radio, remove three bolts

securing ignition shield over distributor and coil.

One bolt is accessible from the top of shield, the

other two are at rear of shield, facing firewall.

2.
Disconnect tachometer drive cables from distributor

housing.

3.
Disconnect pickup coil leads at connector.

4.
Remove distributor cap.

5. Crank engine so rotor is in position to fire No. 1

cylinder and timing mark on harmonic balancer is

indexed with pointer.

6. Remove vacuum line from distributor.

7. Remove distributor clamping screw and hold-down

clamp.

8. Remove distributor and distributor-to-block gasket.

It will be noted that the rotor will rotate as the

distributor is pulled out of the block. Mark the re-

lationship of the rotor and the distributor housing

after removal so that the rotor can be set in the

same position when the distributor is being installed.

DISASSEMBLY (Fig. 16i)

NOTE:
If a distributor is being disassembled

for replacement of the stationary magnetic

pickup assembly only, it will be necessary to

perform only Steps 3, 4, 5, 7, 8, 9, and 12 of the

service procedure listed below.
1.
Remove screws securing rotor and remove rotor.

2.
Remove centrifugal weight springs and weights.

3.
Remove the tachometer drive gear from the distribu-

tor (Corvette only).

4.
Remove roll pin, then remove distributor drive gear

and washer.

CAUTION: To prevent

magnet, support drive gear
;e to the permanent

?n
driving out roll

pin.

5. Remove drive shaft assembly.

6. Remove centrifugal weight support and timer core

from drive shaft.

7. Remove connector from pickup coil leads.

8. Remove retaining ring which secures magnetic

core support plate to distributor shaft bushing in

housing.

9. As a unit, remove the entire magnetic pickup assem-

bly from the distributor housing.

10.
Remove brass washer and felt pad.

11.
Remove vacuum advance unit.

12.
To reassemble distributor, perform the above steps

in reverse order.

INSTALLATION (CORVETTE)

1.
Check to see that the engine is at firing position for

No.
1 cylinder (timing mark on harmonic balancer

indexed with pointer).

2.
Position a new distributor-to-block gasket on the

block.

3.
Before installing distributor, index rotor with hous-

ing as noted when distributor was removed. Install

distributor in block so that vacuum diaphragm faces

approximately 45° forward on the right side of the

engine and the rotor points toward contact in cap for

No.
1 cylinder.

4.
Replace distributor clamp leaving screw loose

enough to allow distributor to be turned for timing

adjustment.

5. Install spark plug wires in distributor cap. Place

wire for No. 1 cylinder in tower (marked on old cap

during disassembly) then install remaining wires

clockwise around the cap according to the firing

order (1-8-4-3-6-5-7-2).

6. Attach distributor to coil primary wires.

7. Replace distributor cap.

8. Adjust timing and then fully tighten distributor clamp

screw.

9. Attach vacuum line to distributor.

10.
Connect tachometer drive cables to distributor body.

11.
Replace ignition shields.

DISTRIBUTOR OFF-ENGINE TEST

The distributor's centrifugal and vacuum advance can

be checked in a distributor testing machine or synchro-

scope specially adapted or designed to accommodate this

type distributor. However, since this involves removing

the distributor from the engine, this test may be post-

poned until other system checks have been made. A dwell

reading cannot be obtained on this distributor and it is not

likely that the centrifugal or vacuum advance will be a

cause of trouble.

COIL REPLACEMENT

1.
Disconnect ignition switch and distributor leads from

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-ELECTRICAL 6Y-29

each capacitor (not illustrated). The capacitor is

shorted if both readings are zero.

6. Resistor Rl: The resistor is open if both readings

are infinite.

7. Resistor R2: Use an ohmmeter scale on which the

1800 ohm value is within, or nearly within, the

middle third of the scale. If both readings are infi-

nite, the resistor is open.

8. Resistor R3: Use an ohmmeter scale on which the

680 Ohm value is within, or nearly within, the middle

third of the scale. If both readings are infinite, the

resistor is open.

9. Resistor R4: Select an ohmmeter scale on which the

15000 ohm value is within, or nearly .within, the

middle third of the scale. If either reading is infi-

nite, the resistor is open. ~

10.
Resistor R5: Use the lowest range ohmmeter scale.

The resistor is open if either reading is infinite.

NOTE:
This resistor on some applications may

be located in the vehicle wiring harness, and not

on the panel board.

11.
Resistor R6: An ohmmeter scale on which the 150

ohm value is within or nearly within, the middle

third of the scale should be used. If both readings

are infinite, the resistor is open.

REASSEMBLY

During assembly, coat with silicone grease both sides

of the flat insulators used between the transistors and

heat sink, and also the heat sink on the side on which the

transistors are mounted. The silicone grease, which is

available commercially, conducts heat and thereby pro-

vides better cooling.'

IGNITION PULSE AMPLIFIER

R-5

C-3 Ju

MAGNETIC PULSE

DISTRIBUTOR
IGNITION SWITCH REPLACEMENT (Figs.
21
i to 23i)

CHEVROLET, CHEVY II AND CORVETTE

1.
Raise hood and disconnect battery ground cable from

battery.

2.
Remove lock cylinder by positioning switch in "off"

position and inserting wire in small hole in cylinder

face. Push in on wire to depress plunger and con-

tinue to turn key counter-clockwise until lock cylin-

der can be removed.

3.
Remove the metal ignition switch nut from the pas-

senger side of the dash using Tool J-7607 (Fig. 21i).

4.
Pull the ignition switch out from under the dash and

remove the wiring connectors.

5. To remove the "theft resistant" connector, the

switch must be out from under the dash as outlined

in Step 4. Using a screw driver unsnap the locking

tangs on the connector from their position on the

switch as shown in Figure 22i. Unplug the connector.

6. Snap the connector into place on a new ignition

switch.

7. Place the switch into position from behind the dash

and install the metal ignition switch nut.

8. Install the lock cylinder.

9. Install the battery cable to the battery and lower the

hood.

CHEVELLE

1.
Disconnect battery ground cable.

2.
Remove ash tray, retainer attaching screws and

retainer.

3.
Remove A/C distributor duct retaining screws and

duct.

Fig.
19i—Pulse Amplifier Internal Circuitry
Fig.
20i—Transistor Checking

CHEVROLET Oi

ENGINE-ELECTRICAL-6Y-30

Fig.
2 li—Removing Ignition Switch Nut

4.
Remove heater and/or A/C control panel assembly

retaining screws and push panel assembly from

console.

NOTE: If interference between control panel

and radio is encountered, loosen radio retaining

nuts.

5.
Remove radio control knobs, bezels and retaining

nuts.

6. Disconnect radio wiring harness and antenna lead-in.

7.
Remove radio rear brace attaching screw and re-

move radio from vehicle.
Fig.
231—Switch and Connector Unplugged

8. Remove ignition switch bezel nut using Tool J-7607

and push switch rearward from panel opening.

9. Disconnect wiring connector from rear of switch.

10.
To install, reverse removal procedure.

SPARK PLUGS

CLEANING AND REGAPPING

Clean the spark plugs thoroughly, using an abrasive-

type cleaner. If the porcelains are badly glazed or

blistered, the spark plugs should be replaced. All spark

plugs must be of the same make and number or heat

range. Use a round feeler gauge to adjust the spark plug

gap to specifications (fig. 24i).

Fig.
22i—Unlocking Ignition Switch Connector

Fig.
241—Setting Sfxirk Plug Gap

CHEVROLET CHASSIS SERVICE MANUAL

CLUTCH AND TRANSMISSIONS 7-2

Fig.
2 - Chevelle Clutch Pedal Free Travel Adjustment (V-8 Shown)

some clearance between cross shaft and both its

mounting brackets.

CLUTCH LINKAGE ADJUSTMENT

There is one linkage adjustment (clutch fork push rod

or pedal push rod) to compensate for all normal clutch

wear.

The clutch pedal should have
1-1/4"
free travel (meas-

ured at clutch pedal pad) before the throwout bearing en-

gages the clutch diaphragm spring levers. Lash is re-

quired to prevent clutch slippage which would occur if the

bearing was held against the fingers and to prevent the

bearing from running continually until failure.

Chevrolet Linkage Adjustment (Fig. 1}

With Nuts (A) & (B) loose on Rod (D)
&
before installa-

tion of Clutch Pedal Return Spring
(E),
apply approximately

5 lbs. load in direction of arrow (F) to eliminate clear-

ance between throwout bearing and clutch fingers. Move

Rod (D) in direction of arrow (G) until Clutch Pedal Arm

makes contact with Bumper Stop on instrument panel

brace. Run Nut (B) toward Swivel until dimension (X) is

9/32". Tighten Nut (A) to lock Swivel (C) against Nut (B).

Install Clutch Pedal Return Spring (E).

The foregoing procedure will provide a free pedal

travel of 1" to
1-1/2"
measured on a perpendicular from

the crown of the, pedal pad to the bare metal toe pan.

Chevelle Linkage Adjustment (Fig. 2)

1.
Disconnect spring between cross shaft lever and

clutch fork.

2.
Loosen push rod locknut about three turns.

3.
If there is no free travel, shorten the rod (by turning

at square wrench area) until it is free of clutch fork.

4.
Hold the clutch fork rearward to move throwout

lightly against clutch release fingers, then adjust rod

length until rod just touches ,its seat in the fork.
5.
Adjust locknut to obtain approximately 3/16" clear-

ance between nut and rod sleeve end.

6. Turn the rod with wrench, until the nut just comes in

contact with rod sleeve end, then hold the rod with

wrench and tighten locknut.

7.
Check free pedal travel at pedal (1" to
1-1/2"
is

proper clearance). Readjust if necessary.

Chevy II Linkage Adjustment (Fig. 3}

L-4 & L-6 Models

1.
Loosen locknut "A" and lengthen or shorten push rod

in swivel as required by turning with wrench on ma-

chined flat "B". (Shorten push rod to increase pedal

lash).

2.
Hold push rod at flat "B" and tighten locknut "A".

3.
Recheck pedal free travel.

NOTE: A measurement of approximately 3/16"

between push rod and its seat in fork will give

required pedal free travel.

V-8 Models

The eight cylinder linkage has a two-piece clutch fork

push rod (fig. 3). Adjust clutch pedal free travel by turn-

ing the adjusting rod portion of the push rod to obtain apr

proximately 3/16" clearance between clutch fork and end

of rod, ttien tighten locknut to 8-12 lbs. ft. and check free

travel at pedal. Pedal free travel on all models should

be 1" to
1-1/2".

Corvette Linkage Adjustment

Refer to fig. 1 and the following procedure:

1.
Disconnect pedal return spring.

2.
With Nuts (A) and (B) loose on Rod (D) apply push

hard load in direction of arrow (F) to eliminate

clearance between throwout bearing and clutch

fingers.

3.
Run Nut (B) towards Swivel (C) until dimension (X)

is 3/8" to 7/16".

4.
Tighten Nut (A) to lock swivel against Nut (B).

5.
Connect pedal return spring and check pedal free

travel for
1-1/4"
minimum to 2" maximum.

6. Check every 3,000 miles.

7.
Adjust free travel to 2" to 2-1/2" for heavy duty op-

eration. The return spring may be removed for

heavy duty conditions.

Camaro Linkage Adjustment

Refer to Figure 4 and the following procedure:

Apply a 10 lb. load in direction of Arrow (E) to hold

Clutch Pedal against Clutch Pedal Bumper.

Apply a 10 lb. load to Clutch Fork in direction of Arrow

(D) to eliminate clearance between throwout bearing and

clutch fingers.

Insert a .198 Spacer (F) between clutch fork and Ad-

justing Rod (A).

Rotate Adjusting Rod against Spacer until it has a 5 in.

lb.
torque.

Hold Adjusting Rod and tighten Nut (C) against Swivel

(B) or Rod (B).

Remove Spacer. Install return spring and extension to

clutch fork.

Pedal will have approximately 1" to
1-1/8"
free travel.

A clutch that has been slipping prior to free play ad-

justment may still slip right after the new adjustment due

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 7-3

DETENT CAM

DETENT SPRING

DETENT CAM

2-3 SHIFT

FORK

DETENT CAM

PIVOT PIN

1ST & REV. 1ST& REV.

SHIFTER SHAFT SHIFT FORK

DETENT CAM

RETAINER RING
2-3 SHIFTER SHAFT

Fig. 3A
•*
Transmission Side Cover, Shift Fork and Detent Assembly

5. Reinstall propeller shaft and any items removed to

obtain clearance.

TRANSMISSION SIDE COVER

Removal •

1.
Disconnect control rods from levers; remove 2-3

cross shaft (Chevrolet)

2.
Shift transmission into neutral detent positions before

removing cover.

3.
Remove cover assembly from transmission case

carefully and allow oil to drain.
Disassembly (Fig. 3A)

1.
Remove the outer shifter levers.

2.
Remove both shift forks from shifter shaft assem-

blies.
Remove both shifter shaft assemblies from

cover. "OM ring seals around shifter shaft may now

be pryed out if replacement is required because of

damage.

3.
Remove detent cam spring and pivot retainer "C"

ring. Remove both detent cams.

4.
Replace damaged parts.

Assembly (Fig. 3A)

1.
With,
detent spring tang projecting up over the
2nd
and

3rd shifter shaft cover opening install the first and

reverse detent cam onto the detent cam pivot pin.

With the detent spring tang projecting up over the

first and reverse shifter shaft cover hole install the

2nd an£ 3rd detent cam.

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

and hook spring into detent cam notches.

3.
Install both shifter shaft assemblies in cover being

careful not to damage seals. Install both shift forks

to shifter shaft assemblies^ lifting up on detent cam

to allow forks to fully seat into position.

4.
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.

3.
Install cover attaching bolts and tighten evenly to

specified torque.

4.
Remove filler plug and add lubricant specified in

Section 0, to level of filler plug hole.

COMPONENT PART REPLACEMENT

TRANSMISSION REPLACEMENT (EXC. CORVETTE)

Removal From Vehicle

1.
Remove propeller shaft assembly.

2.
Disconnect speedometer cable at transmission.

3.
Disconnect shifter rods at transmission levers.

4.
Support engine assembly.

5. Remove transmission to clutch housing bolts.

6. Remove transmission crossmember to mount bolts.

7. Loosen transmission crossmember and move rear-

ward or remove.

8. Slide transmission rearward and remove.

Installation in Vehicle

1.
Raise transmission into position and slide forward

piloting clutch gear retainer into clutch housing.

2.
Install transmission to clutch housing retaining bolts

and lock washers, torque to 50 ft. lbs.

3.
Repositioning transmission crossmember and install

retaining bolts.

4.
Install transmission crossmember to mount bolts.

5. Connect and adjust shift rods at transmission levers

and cordon shaft to 2nd and 3rd lever on Chevrolet

Models. (Fig. 4A)
Fig. 4A - Chevrolet 2-3 Shift Lever Cordon Shaft

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