HEATER AND AIR. CONDITIONING 1A-24
Fig. 35-Controls-AII Weather (Chevy II)
The heater components of the system are similar to
the standard Corvette heater with hoses routing engine
coolant to and from the heater core. A vacuum operated
shutoff valve assures that no coolant will pass through
the heater core until the system calls for heat.
Four control knobs surrounding the clock on the in-
strument panel center console provide full control of the
heating and cooling functions of the air conditioning
system.
The general arrangement of the system components
is pictured in Figure 37 while a schematic view of the
system will be found in Figure 36.
Controls Corvette
Four control knobs, grouped around the clock on the
instrument panel central console, provide full control
of the heating and cooling functions of the Corvette Air
Conditioning System. Each of the knobs, through a bowden
cable, operates one of the air diverter doors in the air
distributor assembly. In addition, the AIR COND.-PULL
knob operates the compressor switch; blower speeds are
controlled by turning the AIR PULL knob; and the heater
hot water valve vacuum switch is actuated by the COOL
IN-HQT PULL knob.
Air Conditioning "ON" Knob
The "AIR COND. PULL" knob controls the positioning
of the air diverter door which routes conditioned air
through either the dash diffuser ducts or the floor dis-
tributor outlets. Movement of this knob (hence, movement
of the selector door) also controls' the compressor
switch. When the door is positioned to send air through
the dash outlets the compressor is automatically turned
on to place the cooling system in operation and the fan
is turned on to LOW speed.
Blower Switch and Air Selector
The AIR PULL-FAN knob operates the selector door
in the right hand plenum chamber and may be set to allow
full outside air, full inside air, or a mixture of the two to
DEFROSTER DOOR
OPERATED BY
DEFROSTER KNOB
AIR CONDITIONING DOOR
OPERATED BY
AIR COND. PULL KNOB
BLOWER
OPERATED
BY TURNING
AIR KNOB
AIR DOOR
OPERATED
BY PULLING
AIR KNOB
OUTSIDE
AIR
CONTROLS
HEAT DOOR
OPERATED BY
COOL IN-HOT PULL
KNOB
L.H. OUTLET
CENTER
OUTLET
R.H. OUTLET
AIR COND.
PULL
COOL IN
HOT PULL
AIR PULL
LO-MED-HI
DEFROSTER
PULL
Fig.
36—Corvette Four-Season System Schematic
CHEVROLET CHASSIS SERVICE MANUAL
HEATER AND AIR CONDITIONING 1A-25
Fig.
37—-Corvette Four-Season System Components
pass through the system. For heating operations it is
suggested that Ml outside air (knob Mly OUT) be used.
For cooling operations under extreme heat conditions
push knob fully in (recirculated inside air); under moder-
ate temperature conditions pull the knob out to the detent
position (a misxture of outside air and inside air); and
under mild temperature conditions the knob may be
pulled fully out (outside air).
After the AIR PULL knob is set to permit air to pass
through the system, the knob may be rotated to control
the three-speed blower. When the AIR COND.-PULL
knob is pulled out the low blower is in operation. Select
higher speeds as desired.
Temperature Adjustment
The COOL IN-HOT PULL knob controls the air output
temperature during both heating and cooling operations.
A vacuum switch (operated by the temperature door
actuating cam) controls a vacuum operated water valve
which allows engine coolant to flow through the heater
core only when this knob is pulled out.
During heating operation cold ambient air enters the
conditioner, passes through the inoperative cooling core
and then passes through and around the heating core
(the final mixture of hot and cold air being determined
by the control knob - temperature door setting) and then
enters the car.
Cooling operation is exactly the same except that the
cooling core (evaporator) will be in operation at Ml
capacity, removing as much heat and humidity as pos-
sible from the warm ambient air flowing through it.
The COOL IN-HOT PULL knob may then be pulled out
as needed to temper this maximum cold airflow should
it become necessary.
Defroster Control
This control acts to divert heated air from the floor
distributor duct into the defroster duct for windshield
defogging, defrosting and deicing operations. A detent
is built into the defroster linkage to indicate the setting
at which a small portion of the heater air will be con-
tinaully passed over the windshield, thus keeping it clear.
Operating Instructions
Remember that the air conditioning system may be
used for heating or cooling during any season of the
year to provide just the desired comfort conditions.
Cooling
1.
"Air Cond-Pull". This knob should be pulled fully
out.
2.
"Cool In-Hot Pull". This knob should be pushed
fully in for maTriTr»"Tn cooling. Pulling out the knob
as required will mix warm air with the cool air to
temper the cool air output.
3.
"Air Pull-Fan". Set this knob fully in during ex-
treme heat conditions; at the detent position during
moderate temperature conditions; fully out during
mild temperature conditions or whenever tempering
of the cooled air flow is necessary. Turn the knob
CHEVROLET CHASSIS SERVICE MANUAL
HEATER AND AIR CONDITIONING 1A-26
clockwise for medium and high blower speed, as
desired. Low blower speed is automatic during
cooling operations.
4.
"Def-Pull". This knob should be pushed fully in.
Additional Cooling Hints
1.
The center barrel outlet in the dash may be rotated
to deflect air as desired or used to act as a shut off
door.
2.
The right and left ball outlets may be rotated to
deflect air in the direction desired. Each outlet has
a shut off valve operated by a knob approximately
4 in. inboard. When the knob is horizontal, the valve
is open.
3.
There are two (2) additional outlets in the bottom of
the ducts approximately 6" inboard from the valve
knobs. A rotating cover will open these outlets to
provide cool air for the feet if desired.
4.
When first entering a very warm car, open the
windows for a few minutes until the interior of the
car has cooled off.
Heating
1.
"Air Pull-Fan". Pull this knob fully out. Rotate
the knob clockwise for low, medium or high blower
speed as desired. If just a small amount of heat is
desired, leave the fan on low or medium speed and
regulate the temperature with the "Cool In-Hot Pull"
knob.
2.
"Air Cond-Pull". This knob should normally be
pushed fully in. However, during cool, damp days
it is possible, by pulling this knob fully out, to de-
humidify the air by passing it through the evaporator
core before reheating to the desired outlet
temperature.
3.
"Cool In-Hot Pull". Pull this knob out as far as
necessary to provide the temperature desired.
4.
"Def-Pull". Pull this knob all the way out for
maximum defrosting or de-icing. When the knob is
partly out, a portion of the hot air is used for de-
frosting and the balance is discharged through the
heater outlet.
GENERAL INFORMATION
In any vocation or trade, there are established proce-
dures and practices that have been developed after many
years of experience. In addition, occupational hazards
may be present that require the observation of certain
precautions or use of special tools and equipment. Ob-
serving the procedures, practices and precautions of
servicing refrigeration equipment will greatly reduce the
possibilities of damage to the customers' equipment as
well as virtually eliminate the element of hazard to the
serviceman.
PRECAUTIONS IN HANDLING REFRIGERANT-12
Refrigerant-12 is transparent and colorless in both the
gaseous and liquid state. It has a boiling point of 21.7^
below zero and, therefore, at all normal temperatures
and pressures it will be a vapor. The vapor is heavier
than air and is noninflammable, nonexplosive, non-
poisonous (except when in contact with an open flame)
and noncorrosive (except when in contact with water).
The following precautions in handling R-12 should be
observed at all times.
• All refrigerant drums are shipped with a heavy metal
screw cap. The purpose of the cap is to protect the
valve and safety plug from damage. It is good .prac-
tice to replace the cap after each use of the drum.
• If it is ever necessary to transport or carry a drum
or can of refrigerant in a car, keep it in the luggage
compartment. Refrigerant should not be exposed to
the radiant heat from the sun for the resulting in-
crease in pressure may cause the safety plug to
release or the drum or can to burst..
• Drums or disposable cans should never be subjected
to high temperature when adding refrigerant to the
system. In most instances, heating the drum or can
is required to raise the pressure in the container
higher than the pressure in the system during the
operation. It would be unwise to place the drum on a
gas stove, radiator or use a blow torch while pre-
paring for the charging operation, for a serious ac-
cident can result. Don't depend on the safety
plug - many drums have burst when the safety plug
failed.' Remember, high pressure means that great
forces are being exerted against the walls of the
container. A bucket of warm water, not over 125°F,
or warm wet rags around the container is all the heat
that is required.
• Do not weld or steam clean on or near the system.
Welding or steam cleaning can result in a dangerous
pressure buildup in the system.
• When filling a small drum from a large one, never
fill the drum completely. Space should always be
allowed above the liquid for expansion. If the drum
were completely full and the temperature was in-
creased, hydraulic pressure with its tremendous
force would result.
• Discharging large quantities of R-12 into a room can
usually be done safely as the vapor would produce
no ill effects, however, in the event of an accidental
rapid discharge of the system it is recommended
that inhalation of large quantities of R-12 be avoided.
This caution is especially important if the area con-
tains a flame producing device such as a gas heater.
While R-12 normally is nonpoisonous, heavy con-
centrations.. of it in contact with a live flame will
produce a toxic gas. The same gas will also attack
all bright metal surfaces.
• Protection of the eyes is of vital importance! When
working around a refrigerating system, an accident
may cause liquid refrigerant to hit the face. If the
eyes are protected with goggles or glasses, no
serious damage can result. Just remember, any
R-12 liquid that you can touch or that touches you is
at least 21.7"F. below zero. The eyeballs can't take
much of this temperature. If R-12 liquid should
strike the eyeballs, here is what to do:
1.
Keep calm.
2.
Do not rub the eyes! Splash the affected area with
quantities of cold water to gradually get the tem-
perature above the freezing point. The use of min-
eral, cod liver or an antiseptic oil is important in
CHEVROLET CHASSIS SERVICE MANUAL
HEATER AND AIR CONDITIONING 1A-62
2.
Insert the evaporator assembly into the outlet case
half and mount the evaporator, thermostatic switch,
and cable to the case.
3.
Install the face plate to the case and install control
retaining nuts and knobs.
4.
Assemble the case halves and mount the evaporator
pipe clamp.
5. Install the evaporator assembly as previously
described under EVAPORATOR.
BLOWER ASSEMBLY
Four-Season System
Chevrolet and Camaro
Removal
1.
Disconnect battery ground cable.
2.
Remove the right front fender and skirt assembly.
3.
Disconnect the motor wire at the flange connector.
4.
Disconnect the rubber air cooling tube from the
motor.
5. Remove the motor to case attaching screws and re-
move the blower assembly. If the sealer acts as an
adhesive, pry the assembly carefully away from the
6. Remove the blower from the motor shaft.
Fig.
86—Blower Assembly—Four-Season (Chevrolet,
Chevelle, Camaro)
Installation
1.
Mount the blower to the motor shaft with the open end
of the blower away from the motor.
2.
Mount the assembly to the case with the attaching
screws.
3.
Connect the rubber tube and blower wire to the
motor.
4.
Replace the right front fender and skirt assembly.
5. Connect battery ground cable.
Chevelle
The blower assembly (fig. 86) is mounted to the dash
panel and contains the outside air-recirculated air
diverter door, the heating-cooling diverter door, the air
conditioning relay and resistor, the compressor actuating
switch, and the blower motor.
Replacement
1.
Disconnect the blower motor "hot" wire at the con-
nector and the ground lead on the Chevrolet.
2.
Detach the rubber cooling tube from the blower as-
sembly and remove the five bolts attaching the
blower motor to the blower assembly.
3.
Remove the motor and fan, disassemble fan from
motor and install on a new motor. If, because of
engine accessories, hoses restrict lifting the blower
assembly from the engine compartment, remove
blower from motor and lift units out separately.
Assemble replacement units under the restricting
hoses.
4.
Reinstall motor and fan into blower assembly. Re-
place cooling tube, ground wire and connect hot wire
to connector.
5. Check blower operations.
Corvette
Replacement
1.
Remove the radiator overflow tank and brackets and
pull the tank out of the way as far as the length of the
heater hose will permit.
2.
Disconnect the electrical connector and the rubber
air inlet tube from the blower motor.
3.
Remove the five blower flange to case attaching
screws and carefully remove the blower motor and
drum assembly.
4.
Remove the blower drum assembly and reinstall on
a new blower motor.
5. Replace the blower motor and drum assembly in the
case and reinstall all screws, hoses and electrical
connections.
All-Weather System
Chevy II
Removal
Under the Hood
1.
Purge the refrigerant from the system.
2.
Drain the radiator.
3.
Remove the refrigerant hoses at the evaporator
pipes.
4.
Remove the evaporator pipe clamp and grommet.
5. Remove three nuts from the blower case studs which
pass through the firewall.
6. Remove heater hoses from core tubes.
CHEVROLET CHASSIS SERVICE MANUAL
REAR SUSPENSION AND DRIVE LINE 4-30
Fig.
76—Differential Gear Failure
Hypoid Gears
Hypoid gear tooth scoring (fig. 74) is caused generally
by improper break-in, incorrect lube, insufficient gear
backlash or improper 'ring/pinion gear alignment. The
scoring will progressively lead to complete erosion of
the gear tooth, or gear tooth pitting and eventual fracture
with possible attendant damage to bearings, if the initial
scoring condition is not diagnosed in time and corrected.
Hypoid gear scoring is easily recognized by its char-
acteristic loud whine in either drive, coast or under both
conditions. Another cause of hypoid tooth fracture (fig.
75) is extended overloading of the gear set which will
produce fatigue fracture, or shock loading which will
result in sudden failure.
Differential Gears
Common causes of differential gear failure are shock
loading, extended overloading leading to fatigue failure,
and overheating of gear thrust surfaces resulting from
excessive wheel spin and consequent lubrication break-
down. Overheating will lead to seizing of thrust surfaces
or tooth failure (fig. 76).
Bearings
• Failure of axle tapered roller bearings is due pri-
marily to excessive wear caused by long service or
foreign materials in the oil. The second most common
cause of bearing failure is too tight or too loose pre-
load adjustment leading to spalling and eventual failure.
This failure may also lead to hypoid gear scoring due to
the resultant misalignment of the hypoid gear set.
COMPONENT PARTS REPLACEMENT
(Chevrolet, Cheveile, Chevy II and Camaro)
AXLE ASSEMBLY
Removal
1.
Raise vehicle to a height that will permit axle as-
sembly to hang freely and position supports under
both frame side rails.
2.
Disconnect wheel cylinder inlet lines. Disconnect and
remove brake hose and brake line retaining bracket
by removing retaining bolt from carrier cover.
3.
Loosen parking brake equalizer adjusting nut and
disconnect both rear cables at frame bracket and at
control arms. See Section 5 for detail of parking
brake cable removal.
4.
Remove two trunnion bearing "U" bolts from the
rear yoke and separate rear universal joint. Wire
propeller shaft to frame side rail and tape trunnion
bearing cups.
5. Support arid secure axle assembly with an adjustable
lifting device. On Chevrolet and Cheveile models,
loosen upper and lower control arm attaching bolts
at axle housing. (On Chevrolet models, disconnect
tie rod at axle bracket.)
6. Disconnect shock absorbers at axle brackets. Refer
to Shock Absorber Removal procedures outlined in
this section.
7. On Chevrolet and Cheveile models, lower axle as-
sembly until suspension reaches end of travel, then
disconnect spring retainers and withdraw springs
from vehicle.
8. On Chevy II and Camaro models, remove four nuts
securing lower spring seat to axle housing, then
remove spring front eye bolts or spring attaching
bracket and swing spring to rear so that it does not
interfere with axle.
9. On Chevrolet and Cheveile models, disconnect upper
and lower control arm attaching bolts at axle housing*
10.
Lower axle assembly and remove from under vehicle.
Installation
1.
Place axle assembly under vehicle and raise into
position.
2.
On Chevrolet and Cheveile models, install, but do not
tighten, upper and lower control arm attaching bolts
at axle housing.
3.
On Chevrolet models, position coil springs in upper
seats so that end of spring is indexed in seat.
4.
On Chevrolet models, install lower end of spring on
axle bracket or control arm and secure by installing
retainer and bolt. Install lock washer and retainer
nut.
5. On Cheveile pry lower pigtail of spring over vertical
flange of the axle bracket spring seat.
6. On Chevy II and Camaro models, install spring seat
pads and swing springs up into spring seats on axle
housing, making sure upper seat pads are aligned in
axle housing bracket.
7. Install spring front eye bolt and tighten, then install
spring seat lower mounting bracket and retaining
nuts.
8. Raise axle assembly to allow shock absorber and tie
rod installation. Position shock absorber in axle
bracket. Torque nut as outlined in Shock Absorber
Installation procedures.
9. Install brake hose and brake line retaining bracket
to carrier and connect wheel cylinder inlet lines.
Connect parking brake cable to frame bracket and
at control arm. Adjust parking brake and bleed
brakes as outlined in Section 5.
10.
Reassemble rear universal joint to companion flange.
11.
Support vehicle at axle and remove supports from
beneath the frame side rails.
12.
Remove supports and lower vehicle to floor. Torque
all affected parts to specifications.
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE-ELECTRICAL 6Y-33
O
V-8 ENGINE
STARTING MOTOR
Fig.
2s—V-8 Starting Circuit Diagram
2.
3.
From battery negative post
To
starting motor
housing.
From solenoid battery terminal
To
solenoid motor
terminal.
If voltage drop
in
any
of
above check exceeds 0.2 volts,
excessive resistance
is
indicated in that portion
of
start-
ing circuit
and the
cause
of the
excessive resistance
should
be
located
and
corrected
in
order to obtain maxi-
mum efficiency in the circuit.
CAUTION:
Do not
operate
the
starting motor
continuously
for
more than
30
seconds
to
avoid
overheating.
When
the
solenoid fails
to
pull
in, the
trouble may be
due
to
excessive voltage drop in the solenoid control cir-
cuit.
To
check
for
this condition, close
the
starting
switch
and
measure
the
voltage drop between
the
BAT-
TERY terminal of the solenoid and the
SWITCH (S)
termi-
nal
of
the solenoid.
1.
If
this voltage drop exceeds 3.5 volts, excessive
re-
sistance
in the
solenoid control circuit
is
indicated
and should be corrected.
2.
If the
voltage drop does not exceed 3.5 volts and the
solenoid does not pull in, measure the voltage availa-
ble
at
the SWITCH terminal
of
the solenoid.
3.
If the
solenoid does
not
feel warm,
it
should pull
in
whenever the voltage available
at
the SWITCH termi-
nal
is 7.7
volts
or
more. When
the
solenoid feels
warm,
it
will require
a
somewhat higher voltage
to
pull in.
STARTING MOTOR AND SOLENOID CHECK
The following checks
may be
made
if the
specific
gravity of the battery
is
1.215
or
higher.
1.
If the
solenoid does
not
pull in, measure the voltage
between
the
switch
(S)
terminal
of the
solenoid
and
ground with the starting switch closed.
CAUTION:
If the
solenoid feels warm, allow
to
cool before checking.
If
the
voltage
is
less than 7.7 volts, check for ex-
cessive resistance
in the
solenoid control circuit.
If
the
voltage exceeds 7.7 volts, remove the starting
motor
and
check
(1)
solenoid current draw,
(2)
starting motor pinion clearance,
and (3)
freedom of
shift lever linkage.
2.
If
the solenoid "chatters" but does not hold in, check
the solenoid
for an
open "hold-in" 'winding. When-
ever
it is
necessary
to
replace
a
starting motor
solenoid, always check starting motor pinion
clearance.
3.
If
motor engages
but
does
not
crank
or
cranks
slowly, check
for
excessive resistance
in the ex-
ternal starting circuit, trouble within
the
starting
motor,
or
excessive engine resistance
to
cranking.
SERVICE OPERATIONS
STARTING MOTOR
REMOVAL AND INSTALLATION (Fig.
3s)
The following procedure
is a
general guide
for all
vehicles
and
will vary slightly depending
on
series
and
model.
1.
Disconnect battery ground cable at battery.
2.
Raise vehicle
to a
good working height.
3.
Disconnect all wires
at
solenoid terminals.
NOTE: Reinstall
the
nuts
as
each wire
is
dis-
connected
as
thread size
is
different but may be
mixed and stripped.
4.
Loosen starter front bracket (nut on V-8 and bolt on
L-6) then remove two mount bolts.
5.
Remove
the
front bracket bolt
or nut and
rotate
bracket clear
of
work area then lower starter from
vehicle
by
lowering front end first
—
(hold starter
against bell housing
and
sort
of
roll end-over-end).
6. Reverse
the
removal procedure
to
install. Torque
the mount bolts
to
25-35
ft.
lbs. first, then torque
brace bolt.
7.
Check operation
of
starter on vehicle.
Fig.
3s—Starter Mounting
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
ELECTRICAL-BODY AND CHASSIS 12-57
15.
Connect positive lead to battery terminal, lower hood
and test wiper and washer assembly for proper
operation.
WIPER TRANSMISSION
REMOVAL AND INSTALLATION
1.
Remove wiper block and arm assembly from trans-
mission.
2.
Remove glove box door and compartment assembly.
Refer to Section 1 for removal procedures.
3.
Remove three transmission-td-cowl retaining
screws.
4.
Remove wiper transmission retaining clip and re-
move transmission from crank arm. Then remove
transmission through the glove box opening.
5.
Reverse removal procedure to install wiper trans-
mission.
Fig.
94 - Wiper and Trans Installed
WIPER ASSEMBLY REPAIRS
The overhaul procedures for the wiper are broken down
into three major areas: The motor section, gear box
section and washer pump section. Each section may be
serviced independently of the other.
MOTOR SECTION
Disassembly
1.
Remove the two motor tie bolts.
2.
Remove the armature end-play adjusting screw (fig.
91).
3.
Strike the steel case lightly with a mallet to partiaUy
loosen it from the die casting housing and motor
field.
4.
Insert a tool through the armature adjusting screw
opening and push against the end of the armature
shaft to back off the case. This will retain the ar-
mature commutator in position between the brushes
until ready to separate the armature from the case.
5.
To separate armature from case while still retaining
the brush springs and brushes in place fashion a
spring similar to that shown in Figure 95 and insert
behind the brush leads as shown.
Fig.
95 - Retaining Armature Brushes
6. Pull the armature out of the case and remove the felt
washer, thrust plate, and rubber thrust disc from the
case assembly bearing as required.
7.
The field windings are pressed into the gear housing
and further disassembly is not recommended; how-
ever, the field leads may be unsoldered from the
brush holders to remove the case.
8. Clean and inspect all parts.
Inspect both the field and armature for damage
due to overheating such as unsoldered electrical
connections.
Check that brush leads are firmly attached both
to the brushes and their connections at the brush
holders.
Check brushes for wear. If brushes are worn to
within 3/16" of brush lead, or pigtail, they should be
replaced.
Check contacts of circuit breaker shown at top of
Figure 95. Clean as required or file lightly to re-
move irregularities.
Inspect all leads from the brush and circuit
breaker plate for worn insulation or tjreaks.
If it was determined by inspection that brush re-
placement was required, proceed as follows:
a. Remove retainer installed during disassembly and
remove brush springs.
b.
Place a hot soldering iron against*brush lead con-
nection on brush holders, remove old bushes, and
nection on brush holders, remove old brushes,
and install new brushes.
c. To reinstall brushes in holders, compress spring
within holder and hold fully compressed with a
thin instrument inserted through the slot in the
brush holder. Then push brush into holder with
lead upward to project through slot in holder, hold
CHEVROLET CHASSIS SERVICE MANUAL