GENERAL INFORMATION 0-3
VEHICLE DIMENSIONS-CHEVY II
Model
Length Overall
Width Overall (Body) . . . .
Height Overall
Wheelbase
Tread-Front
Tread-Rear . . .
Sedan
183.0"
71.3"
56.7"
110.0"
56.8"
56.3"
2-Door
Sport Coupe
183.0"
71.3"
54.4"
110.0"
56.8"
56.3"
Station
Wagon
187.4"
71.3"
57.6"
110.0"
56.3"
55.8"
Curb Weight: Approximately 2668 lbs. 4-Door Sedan with L-4 Engine; 2767
lbs.
with L-6 Engine; 2959lbs.
with V-8 Engine.
MODEL IDENTIFICATION-CAMARO
VEHICLE DIMENSIONS-CORVEnE
Model Number
6-Cyl
12337
12367
V-8
12437
12467
Description
2-Door Sport Coupe, 4-Passenger
2-Door Convertible, 4-Passenger
VEHICLE DIMENSIONS-CAMARO
Model
Length Overall .....
Width Overall (Body) . .
Height Overall
Wheelbase
Tread-Front
Tread-Rear
Sport Coupe
Convertible
184.7"
72.6"
50:8"
108.0"
59.0"
58.88"
Weight: Sport Coupe with L6 Engine 2908 lbs.; with
V-8 Engine 3063 lbs.
MODEL IDENTIFICATION-CORVETTE
Model
Number
19437
19467
Description
2-Door Sport Coupe, 2-Passenger
2-Door Convertible, 2-Passenger
UNIT AND SERIAL NUMBER LOCATIONS
For the convenience of servicemen when writing up
certain business papers, such as L. & M.R.'s Product
Information Reports, or reporting product failures in
any way, we are showing below the location of various
unit numbers. These unit numbers and their prefixes
and suffixes are necessary on these papers for various
reasons—such as accounting, follow-up on production,
etc.
Model
Length Overall
Width Overall (Body). . .
Height Overall.
Wheelbase
Tread-Front
Tread-Rear .
Convertible
Sport
Coupe
175.1"
69.6"
49.8"
49.6"
98.0"
56.8"
57.6"
Curb Weight: 3145 lbs. Convertible
3135 lbs. Sport Coupe
with Base V-8
The prefixes on certain units identify the plant in which
the unit was manufactured, and thereby permits proper
follow-up of the plant involved to get corrections made
when necessary.
Engine Unit Number
The engine unit number (figs. 3 and 4) shows manu-
facturing plant, month and day of manufacture, and
transmission type. A typical engine number would be
F1210FA, which would breakdown thus:
F~Manufacturing Plant (F—Flint, T—Tonawanda)
12—Month of manufacture (December)
10—Day of manufacture (tenth)
FA—Transmission and engine type
Vehicle Serial Number
A typical vehicle serial number tag (fig. 1) yields
manufacturers identity, vehicle type, model year, as-
sembly plant and production unit number when broken
down as shown in the following chart.
Manufacturer
Identity1
1
Body
Style2
5645
Model
Year8
7
Assembly
Plant*
F
Unit
Number5
100025
CHEVROLET CHASSIS SERVICE /MANUAL
ENGINE-ELECTRICAL 6Y-28
terminals on eoil. On Corvettes equipped with radio,
remove bolts securing ignition shield over distribu-
tor and coil.
2.
Pull high tension wire from center terminal of coil.
3.
Remove the two coil support mounting bolts or loosen
friction clamp screw and remove coil.
4.
Place new coil in position and install attaching bolts
or tighten clamp screw.
5.
Place high tension lead securely in center terminal
of coil and connect ignition switch and distributor
primary leads to terminals on coil. Replace ignition
shield on Corvettes.
6. Start engine and test coil operation.
IGNITION PULSE AMPLIFIER
DISASSEMBLY
To check the amplifier for defective components, pro-
ceed as follows:
1.
Remove the bottom plate from the amplifier.
2.
To aid in reassembly, note the locations of the lead
connections to the panel board.
3.
Remove the three panel board attaching screws, and
lift the assembly from the housing.
4.
To aid in reassembly, note any identifying markings
on the two transistors and their respective locations
on the panel board and heat sink assembly.
5.
Note the insulators between the transistors.and the
heat sink, and the insulators separating the heat sink
from the panel board.
6. Remove the transistor attaching screws, and sepa-
rate the two transistors and heat sink from the panel
board.
7.
Carefully examine the panel board for evidence of
damage.
MOUNTING
SCREW
RESISTOR R5 jgSfe. / DIODE Dl
TRANSISTOR TR2
(UNDERNEATH)
1H L >©V
[So
To
I
/'%**jt\
\
TRANSISTC>R"""
1 X ^^w^ X \ (UNDERNEATH)
9^ESISTORR^^^H|^^^^^H
^B
RESISTOR
R4
^HPH^^H
WM'
RESISTOR
R3
I^B^^^^I^U
N .6 ®
mm
N%|/MOUNTING
• tr^i^w ^\ vjR SCREW
CAPACITOR
Cl\
pNkj^^A^
\
RESISTOR
Rl
MOUNTING ^55S^^ \ CAPACITOR C3
SCREW I RESISTOR R6 CAPACITOR C2
TRANSISTOR TR3
COMPONENT CHECKS (Figs. \7\ and 18i)
With the two transistors separated from the assembly,
an ohmmeter may be used to check the transistors and
components on the panel board for defects. An ohmmeter
having a 1-1/2 volt cell, which is the type usually found
in service stations, is recommended. The low range
scale on the ohmmeter should be used except where
specified otherwise.
A 25 watt soldering gun is recommended, and a 60% tin
40%
lead solder should be used when re-soldering. Avoid
excessive heat which may damage the panel board. Chip
away any epoxy involved, and apply new epoxy which is
commercially available.
In order to check the panel board assembly, it is
necessary to unsolder at the locations indicated in Fig-
ure 18i the two capacitors C2 and C3. In all of the fol-
lowing checks, connect the ohmmeter as shown and then
reverse the ohmmeter leads to obtain two readings. The
amplifier circuitry is shown in Figure 19i.
1.
Transistors TR1 and TR2: Check each transistor by
referring to Figure 20i. If both readings in Step 1
are zero, the transistor is shorted. If both readings
in Step 2 are zero, the transistor is shorted; and if
both readings are infinite, the transistor is open.
Interpret Step 3 the same as Step 2.
2.
Trigger Transistor TR3:
11
both readings in Step 1
are zero, the transistor is shorted. If both readings
in Step 2 are zero, the transistor is shorted; and if
both readings are infinite, the transistor is open.
Interpret Step 3 the same as Step 2.
3.
Diode Dl: 11 both readings are zero, the diode is
shorted; and if both readings are infinite, the diode
is open.
4.
Capacitor Cl: If both readings are zero, the capaci-
tor is shorted.
5.
Capacitors C2 and C3: Connect the ohmmeter across
CHECKING
RESISTOR Rl
UNSOLDER
I
CHECKING TRIGGER
TRANSISTOR TR3
CHECKING
CAPACITOR C
Fig.
171—Pulse Amplifier Panel Board
Fig.
18i—Pulse
Amplifier
Component
Checks
CHEVROLET CHASSIS SERVICE MANUAL
CLUTCH AND TRANSMISSIONS 7-33
from rolling. The pointer on the indicator quadrant
should line up properly with the range indicators in all
ranges.
OIL LEAKS
Before attempting to correct an oil leak, the actual
source of the leak must be determined. In many cases
the source of the leak can be deceiving due to "wind flow1 f
around the engine and transmission.
The suspected area should be wiped clean of all oil
before inspecting for the source of the leak. Red dye is
used in the transmission oil at the assembly plant and
will indicate if the oil leak is from the transmission.
The use of a "black light"* to identify the oil at the
source of leak is also helpful. Comparing the oil from
the leak to that on the engine or transmission dip stick
(when viewed by black light) will determine the source
of the leak.
Oil leaks around the engine and transmission are gen-
erally carried toward the rear of the car by the air
stream. For example, a transmission "oil filter tube
to case leak" will sometimes appear as a leak at the
rear of the transmission. In determining the source of
an oil leak it is most helpful to keep the engine running.
The mating surfaces of servo cover, converter housing,
transmission case and transmission case extension
should be carefully examined for signs of leakage. The
vacuum modulator must also be checked to insure that
the diaphragm has not ruptured as this would allow trans-
mission oil to be drawn into the intake manifold. Us-
ually, the exhaust will be excessively smoky if the
diaphragm ruptures due to the transmission oil added to
the combustion. The transmission case extension rear
oil seal should also be checked. All test plugs should be
checked to make sure that they are tight and that there
is no sign of leakage at these points. The converter
underpan should also be removed. Any appreciable quan-
tity of oil in this area would indicate leakage at the pump
square seal ring, pump seal assembly, or pump bolt
sealing washers.
BASIC PRESSURE CHECKS
Four basic pressure checks are used for diagnosis and
operational checks for the Aluminum Powerglide trans-
mission. All checks should be made only after thoroughly
warming up the transmission.
• Wide Open Throttle Upshift Pressure.
• Idle Pressure in "Drive" Range.
• Manual "Low" Range Pressure.
• "Drive" Range Overrun (Coast) Pressure.
It is not recommended that stall tests be conducted
which would result in engine vacuum falling below 10" Hg.
Pressure gauge hose connections should be made at
the low servo apply (main line) test point (fig. 14PG).
Run the gauge line into the driving compartment by
pushing aside the mast jacket seal. The line out of the
way of the drivers feet and connect to pressure gauge
J-21867.
• Wide Open Throttle Upshift Pressure Check
Refer to the pressure check chart for upshift pressure
SERVO APPLY
PRESSURE
Fig.
14PG - Pressure Test Plug
points as indicated on the lower servo apply (main line)
gauge.
• Idle Pressure in "Drive" Range
In addition tp the oil pressure gauges, a vacuum gauge
is needed for this check.
With the parking brake applied and the shift selector
lever in "Drive", low servo apply (main line) pressure
should be as shown on the pressure check chart.
If pressures are not within these ranges, the following
items should be checked for oil circuit leakage:
1.
Pressure regulator valve stuck.
2.
Vacuum modulator valve stuck.
3.
Hydraulic modulator valve stuck.
4.
Leak at low servo piston ring (between ring and
bore).
5.
Leak at low servo piston rod (between rod and bore).
6. Leak at valve body to case gasket.
7.
Leak at valve body gaskets.
8. Front pump clearances.
9. Check passages in transmission case for porosity.
• Manual "Low" Range Pressure Check
Connect a tachometer, apply the parking brake, place
the selector lever in "Low" range, and adjust the engine
speed to 1000 rpm with the car stationary.
Low servo apply (main line) pressure should be as
shown on the pressure check chart.
Pressures not within this range can indicate the fol-
lowing possibilities:
1.
Partially plugged oil suction screen.
2.
Broken or damaged ring low servo.
CHEVROLET CHASSIS SERVICE MANUAL
CLUTCH AND TRANSMISSIONS 7-41
CAUTION: Use converter holding ToolJ-5384
when lowering transmission or keep rear of
transmission lower than front so as not to lose
converter.
The installation of the transmission is the reverse of
the removal.
TURBO HYDRA-MATIC DIAGNOSIS PROCEDURE
Accurate diagnosis of transmission problems begins
with a thorough understanding of normal transmission
operation. In particular, knowing which units are in-
volved in the various speeds or shifts so that the specific
units or circuits involved in the problem can be isolated
and investigated further. Analytical diagnosis will pro-
tect the technician from come backs and certainly will
improve owner satisfaction.
An important and often overlooked aspect of diagnosis
is finding out specifically what the customer is com-
plaining of. For this purpose a short ride with the cus-
tomer will often prove beneficial. It may be found that
the condition the customer wants corrected is standard
and should not be altered.
The following sequence, based on field experience, pro-
vides the desired information quickly and in most cases
actually corrects the malfunction without requiring the
removal of the transmission. Details of the items listed
in this sequence are covered further in the text.
SEQUENCE FOR TURBO HYDRA-MATIC
DIAGNOSIS PROCEDURE
1.
Check oil level and condition.
2.
Check and correct detent switch.
3.
Check and correct vacuum line and fittings.
4.
Check and correct manual linkage.
OIL LEVEL AND CONDITION CHECK
Always check the oil level before road testing. Oil
must be visible on dip stick prior to operating the ve-
hicle. Erratic shifting, pump noise, or other malfunc-
tions can in some cases be traced to improper oil level.
Oil level should be checked with the selector lever in
the Park (P) position, engine running, and the vehicle on
level pavement.
Fluid level should be to the FULL mark with the trans-
mission at normal operating temperature (170°-190°
F.).
With warm fluid (room temperature), the level should be
at or slightly below the ADD mark.
If oil level was low, refer to Oil Leaks.
The condition of the oil is often an indication of whether
the transmission should be removed from the vehicle, or
to make further tests. When checking oil level, a burned
smell and discoloration indicate burned clutches or bands
and the transmission will have to be removed.
MANUAL LINKAGE
Manual linkage adjustment and the associated neutral
safety switch are important from a safety standpoint
The neutral safety switch should be adjusted so that the
engine will start in the Park and Neutral positions only.
With the selector lever in the Park position, the park-
ing pawl should freely engage and prevent the vehicle
from rolling. The pointer on the indicator quadrant
should line up properly with the range indicators in all
ranges.
OIL LEAKS
Before attempting to correct an oil leak, the actual
source of the leak must be determined. In many cases,
the source of the leak can be deceiving due to "wind flow"
around the engine and transmission.
The suspected area should be wiped clean of all oil be-
fore inspecting for the source of the leak. Red dye is
used in the transmission oil at the assembly plant and
will indicate if the oil leak is from the transmission.
. The use of a "black light"* to identify the oil at the
source of leak is also helpful. Comparing the oil from
the leak to that on the engine or transmission dip stick
(when viewed by black light) will determine the source
of the leak.
Oil leaks around the engine and transmission are gen-
erally carried toward the rear of the car by the air
stream. For example, a transmission "oil filler tube to
case leak" will sometimes appear as a leak at the rear of
the transmission. In determining the source of an oil
leak it is most helpful to keep the engine running.
POSSIBLE POINTS OF OIL LEAKS
• 1. TRANSMISSION OIL PAN LEAK
a. Attaching bolts not correctly torqued.
b.
Improperly installed or damaged pan gasket.
c. Oil pan gasket mounting face not flat.
2.
REAR EXTENSION LEAK
a. Attaching bolts not correctly torqued.
b.
Rear seal assembly — damaged or improperly
installed.
c. Gasket seal — (extension to case) damaged or
improperly installed.
d. Porous casting.
3.
CASE LEAK
a. Filler pipe "O" ring seal damaged or missing;
misposition of filler pipe bracket to engine —
"loading" one side of
"O"
ring.
b.
Modulator assembly "O" ring seal
—
damaged or
improperly installed.
c. Governor cover, gasket and bolts — damaged,
loose; case face leak.
d. Speedo gear
—
"O" ring damaged.
e. Manual shaft seal — damaged, improperly in-
stalled.
f. line pressure tap plug — stripped, shy sealer
compound.
g. Parking pawl shaft cup plug
—
damaged, improp-
erly installed.
h. Vent pipe (refer to Item 5).
i. Porous case.
4.
FRONT END LEAK
a. Front seal - damaged (check converter neck for
nicks,
etc., also for pump bushing moved for-
ward);
garter spring missing from pump to con-
verter seaL
b.
Pump attaching bolts and seals
—
damaged, miss-
ing, bolts loose.
CHEVROLET a
SERVICE
STEERING 9-34
Fig.
64-Over Center Adjustment
transmission fluid "Type A" bearing the mark
"AQ-ATF" followed by a number and the suffix
letter "A".
ADJUSTMENTS
POWER STEERING GEAR
Chevrolet, Chevelle, and Camaro
The over-center adjustment (fig. 64) is the only power
steering gear adjustment which can be made on the car.
However, in order to make this adjustment, it is also
necessary to check the combined ball and thrust bearing
preload.
If the vehicle is equipped with a tilt column it will be
necessary to disconnect the steering coupling to obtain a
torque reading of the column. This torque should then be
subtracted from any reading taken on the gear.
1.
Disconnect the pitman arm from the relay rod.
2.
Loosen the pitman shaft adjusting screw loeknut and
thread the adjusting screw out to the limit of its
travel through the side cover. '. •
3.
Disconnect steering column harness at chassis wir-
ing connector plug.
4.
Remove horn button.
5.
Turn the steering wheel through its full travel, then
locate the wheel at its center of travel.
6. Gheck the combined ball and thrust bearing preload
with an inch-pound torque wrench on the steering
shaft nut by rotating through the center of travel
(approximately 1/4 turn in each direction). Note the
highest reading.
7.
Tighten the pitman shaft adjusting screw and check
torque at steering shaft nut until over center preload
and total steering gear preload falls within speci-
fications. Refer to torque specifications at rear of
manual for correct torque values.
8. Install horn button. Connect steering column harness
at wiring connector plug.
Chevy II and Corvette
The steering gear used with power steering is adjusted
in the same manner as the manual steering gear.
PUMP BELT TENSION
1.
Loosen nut on pivot bolt and pump brace adjusting
nut.
CAUTION: Do not move pump by prying against
reservoir or by pulling on filler neck.
2.
Move pump, with belt in place until belt is tensioned
to specifications as indicated by Tool J-7316 (Fig-.
65).
3.
Tighten pump brace adjusting nut. Then tighten pivot
bolt nut.
HYDRAULIC SYSTEM CHECKS
The following procedure outlines methods to identify
and isolate power steering hydraulic circuit difficulties.
This test is divided into two parts. Test number one
provides means of determining whether power steering
system hydraulic parts are actually faulty. If test number
one results in readings indicating faulty hydraulic opera-
tion, test number two will identify the faulty part. Be-
fore performing hydraulic circuit test, carefully check
belt tension and condition of driving pulley. Strand
tension of belt should be 125 lbs. on new belts and 75 lbs.
on old belts, as indicated by Tool J-7316 (Fig. 65).
Test Number One—Oil Circuit Open
Engine must be at normal operating temperature. In-
flate front, tires to correct pressure. All tests are made
with engine idling, so adjust engine idle speed to correct
specifications listed in Section 6 and proceed as follows:
a. With engine not running, disconnect flexible pres-
sure line from pump and install Tool J-5176 as
Fig.
65— Checking Belt Tension with Tool J-7316
CHEVROLET CHASSIS SERVICE MANUAL