ELECTRICAL-BODY AND CHASSIS 12-50
SERVICE OPERATIONS
MOTOR SECTION
DISASSEMBLY
NOTE:
Motor section
may be
disassembled
independently
of
the gear box.
Brush Plate and Circuit Breaker Removal
1.
Scribe
a
reference line along the side of the casting
and end cap to insure proper re-assembly.
2.
Remove the two motor thru bolts.
3.
Feed exposed excess length
of
motor leads thru the
casting grommet
and
carefully back
the
case
and
field assembly plus
the
armature away from
the
casting (fig. 76).
NOTE:
It may be
necessary
to
remove
the
armature end play adjusting screw and insert
a
rod thru
the
opening
in
order to apply pressure
against the end of the armature.
4.
Unsolder
the
black lead from circuit breaker
(fig.
77).
5.
Straighten
out the 4
tabs that secure the brush plate
to the field coil retainers (fig. 77).
CAUTION:
Be
careful
not to
break
any of
the
retainer tabs.
6. Install
"U"
shaped brush retainer clip over brush
holder that has brush lead attached to circuit breaker
(fig. 78).
7.
Holding
the
opposite brush from that retained in Step
6, carefully lift
the
brush holder
off the
mounting
tabs
far
enough
to
clear
the
armature commutator
(fig. 78).
8. Allow
the
brush, held
in
Step
7, to
move out
of its
holder. Remove
the
brush spring
and
lift the brush
holder
off
the armature shaft.
Armature Removal
1.
Follow Steps
1
thru
8
under brush plate removal.
2.
Lift armature out
of
case and field assembly.
3.
Remove thrust ball from
end of
armature shaft
as
PUMP
ASSEMBLY
CAM SLOT
DRIVE PLATE
AND
ASSEMBLY
RELAY SWITCH
ASSEMBLY
WASHER PUMP
DRIVE
PIN
Fig.
75
-
Wiper and Washer
Pump
Mechanism
required and save
for
reassembly.
NOTE: Thrust ball
may be
easily removed
with
a
magnet.
MOUNTING
GROMMET
WASHER PUMP COVER
RETAINING RING
STAKE MARKS -
CASE
TO
FIELD
LAMINA
(4
PLACES)
Fig. 74 - Depressed Park 2-Speed Wiper
Fig. 76 - Wiper Motor Separation
CHEVROLET CHASSIS SERVICE MANUAL
ELECTRICAL-BODY
AND
CHASSIS
12-51
7^5
CUT MOTOR LEADS
GENERALAREA
FOR
in|i
BRUSH PLATE
ASSEMBIYI^^H
RETAINER TAB (4)__J^^H
BLACK
LEAD
TO §HH
CIRCUIT BREAKER»^^—
CIRCUIT
F^H^^^^^B
BREAKER)
^^SH^P
IN
THIS
m
•I
i
ii
ii ii H^MWii^A'
I^BRT^i"
BRUSH
•^^k RETAINER CLIP
•
SPUCENOTES:
•
1-SOLID
BLACK
TO
•
SHUNT FIELD COIL
5
2-SERIES
FIELD COIL
I
TO
BLACK WITH PINK
H STRIPE LEAD
w
Fig.
77
-
Circuit Breaker
Case and Field Assembly Removal
1.
Remove brush plate and armature.
2.
The end
case
and
field assembly
is
serviced
as
a
DRIVE PLATE
&*
ASSEMBLY
DRIVE PAWL
IN
PARK POSITION
IN
RELAY SWITCH SLOT
RELAY SWITCH ASSEMBLY
Fig.
79-
Drive Pawl
in
Full Park Position
unit.
To
free
the
field
and
case assembly,
cut the
solid black and black with pink stripe leads
in a
lo-
cation convenient
for
splicing
-
preferably near
the
wiper terminal board. Refer to Figure
76.
Remove steel thrust plate and rubber disc from case
bearing
as
required.
DRIVE
PAWL
ENGAGING
LATCH
ARM
Fig.
78
-
Removing Brush Holder
Fig.
80
-
Relay Assembly
CHEVROLET
CHASSIS SERVICE MANUAL
ELECTRICAL-BODY AND CHASSIS 12-52
GEAR MECHANISM
NOT IN PARK
RELAY SWITCH ATTACHING SCREW
Fig.
81 -
Drive Gear not
in
Park Position
TERMINAL BOARD
1 2 3
RELAY LEADS (RED)
SOLDER TO NO. 1 TERMINAL
RELAY
COIL-RED
TAN-SOLDER TO
SAME RELAY SWITCH TERMINAL WITH RED COIL LEAD
BLACK WITH PINK STRIPE
ASSEMBLY
1.
If new field and case assembly is being installed,
splice the black and black with pink stripe leads of
the new field with the corresponding leads of the
wiper.
2.
Install the rubber thrust disc, steel thrust disc and
felt lubricating washer in the case assembly bearing
in the order indicated.
3.
Lubricate end of armature shaft that fits in case
bearing. Next, install thrust ball in end of shaft.
4.
Assemble armature in the case and field assembly.
5.
Position the partially assembled brush plate over the
armature shaft far enough to allow re-assembly of
the remaining brush in its brush holder;- then position
the brush plate assembly on the mounting tabs in the
position shown in Figure 78.
NOTE: Circuit breaker ground lead will not
reach circuit breaker terminal if brush plate is
positioned wrong.
6. Center the brush plate mounting holes over the
mounting tabs and bend the tabs toward the brush
holders as required to secure the brush plate in
position.
CAUTION: Be sure tabs are centered in brush
plate mounting holes.
7.
Remove brush retainer clips and resolder circuit
breaker ground lead to circuit breaker. Refer to
Figure
8. If new case and field assembly'is used, scribe a line
on it in the same location as the one scribed on the
old case. This will insure proper alignment of the
new case with the scribed line made on the housing
(Step
1
under Brush Plate Removal).
9. Position armature worm shaft inside the housing and,
using the scribed reference marks, line up as near
Fig.
82 - Relay Assembly Wiring
Fig.
83 -
Terminal Board Resistor
CHEVROLET CHASSIS SERVICE MANUAL
ELECTRICAL-BODY AND CHASSIS 12-53
13
10 11
Fig.
84- Drive Gear Mechanism Assembly
1.
Drive Gear Shaft
2.
Drive Pawl
3. Lock Pawl
4.
Coil Spring
5. Drive Gear
6. Relay Assembly
7. Spacer
8. Shield
9. Seal
10.
Washer
11.
Snap Ring
12.
Crank Arm
13.
Nut
10.
1
NOTE:
VIEW SHOWS RELAY SWITCH ASSEMBLY
AND TERMINAL BOARD REMOVED.
GEAR MAY BE REMOVED WITHOUT
DISTURBING RELAY SWITCH
OR TERMINAL BOARD. f* ;<^ / t
\ MAINTAIN GEAR
J ASSEMBLY IN
V POSITION
^^ SHOWN
FT"
DURING
* & REASSEMBLY
WM IN HOUSING
f
INNER SPACER
J WASHER
ft
as possible the case and field assembly with the
housing.
Maintaining the armature in its assembled position
in the case, start the armature worm shaft through
the field and housing bearing until it starts to mesh
with the worm gear. At the same time carefully pull
the excess black and black with pink stripe leads
thru the housing grommet.
DRIVE
PAWL
DRIVE SHAFT AND
PLATE ASSEMBLY
LOCK
PAWL
Fig.
85 - Removing Gear Assembly
Fig.
86 - Lock and Drive Pawl Assembly
CHEVROLET CHASSIS SERVICE MANUAL
ELECTRICAL-BODY AND CHASSIS 12-54
INNER
SPACER
WASHER
LOCK
PAWL
COIL
SPRING
DRIVE,
PAWL
DRIVE
SHAFT
AND
PLATE
ASSEMBLY
DRIVE
AND
LOCK
PAWL
GUIDE
PINS
IN
GEAR
POCKETS
7
DURING
NORMAL
OPERATION
RELAY
LATCH
ARM
IS
HELD
OUT OF
PATH
OF
GEAR
BY
RELAY
MAGNET
11.
12.
Fig. 87 - Drive Gear and Shaft Assembly
CAUTION: It may be necessary at this point to
rotate armature slightly before the armature
worm will engage with worm gear teeth.
Rotate the case as required to align the bolt holes in
the case with those in the housing.
Secure the case to the housing with the two tie bolts.
GEAR BOX SECTION
Fig. 88 - Drive and Lock Pawl Guide Pins in Pockets
(drive pawl away from latch arm, fig. 81), proceed
to Step 3.
Remove relay-switch attaching screw (fig. 80) and
carefully lift the relay-switch assembly out of the
gear box. Unsolder leads from switch terminals as
required. Refer to Figure when resoldering leads.
To remove terminal board assembly simply slide it
out of housing and unsolder leads as required.
The gear box section is subdivided into two areas, (A)
the relay control and latching mechanism and (B) the
drive gear mechanism.
A—Relay Switch and Latch Assembly-
Terminal Board Removal
1.
Remove screws retaining washer pump assembly to
wiper unit.
2.
If wiper pawl is in full park position (drive pawl lo-
cated in magnetic switch assembly slot, fig. 79), it
becomes necessary to remove gear assembly first
(see Gear Assembly Removal).
If wiper gear mechanism is not in park position
VALVE
ASSEMBLY—j
RATCHET ->Mmk
LATC
SPR
HOUT
ING
RELAY COIL
/PAWL SPRING
/ /'
^L / PAWL
|j^»i It
RATCHET
WHEEL
Fig. 89 - Washer Pump Assembly
CHEVROLET CHASSIS SERVICE MANUAL
ELECTRICAL-BODY
AND
CHASSIS
12-55
COVER RELAY COIL
ASSEMBLY
PAWL SPRING
a=-
VALVE ASSEMBLY
RATCHET DOG AND _/_ f1
LATCHOUT SPRING ^—-»*
PAWL
RATCHET WHEEL
J
Fig.
SO
-
Exploded View
of
Pump
Relay Switch—Latch and Terminal Board Assembly
1.
Resolder leads
to
wiper terminal board as required
(fig. 82).
2.
Slide terminal board into wiper housing being careful
to position the terminal board resistor lead as shown
in Figure 83.
3.
Resolder leads
to
relay switch assembly
as
required
(fig. 82).
4.
Position relay-switch assembly
in
housing.
CAUTION:
Be
very careful
to
route leads
in
such
a
manner
as to
avoid having them pinched
between relay and wiper housing.
5. Install relay-switch mounting screw.
6. Assemble gear box cover and washer pump assembly
to wiper being careful that the ground strap
is
prop-
erly connected. Refer
to
Figure 75 for assembly
of
washer pump
to
gear housing.
B-Drive Gear Disassembly (Fig.
84)
1.
Remove washer pump assembly.
2.
Remove crank
arm
retaining nut, crank arm, rubber
seal
cap,
retaining ring, shim washers, shield
and
spacer washer in the order indicated.
3.
Slide gear assembly out
of
housing (fig. 85).
4.
Slide drive plate and shaft out
of
gear and remove the
drive pawl, lock pawl
and
coil spring
as
required.
Drive Gear—Assembly
1.
Position drive pawl
on
drive plate
as
shown
in
Fig.
ure 86.
2.
Assemble lock pawl over drive pawl
as
shown
in
Figure
86.
3.
Slide gear
and
tube over
the
drive shaft (fig. 87).
(Move drive and lock pawls
as
required to allow their
respective pins
to fit in the
gear guide channel,
fig.
88).
4.
Holding
the
gear, manually rotate
the
drive plate
until
the
drive
and
lock pawl guide pins snap into
their respective pockets in the gear (fig. 88).
5. Reinstall coil spring between lock
and
drive pawls
(fig. 88).
IMPORTANT: Be very careful
to
maintain lock
and drive pawl guide pins
in
their respective
pockets during Step
6.
6. Assemble inner spacer washer over gear shaft
and
assemble gear mechanism
in
housing
so
that
it is
positioned with respect to the housing in the approxi-
mate location shown
in
Figure 85.
7. Reassemble
the
outer spacer washer, shield, shim
washers
as
required
to
obtain .005"
max.
end play,
snap ring and rubber seal cap in the order indicated.
Refer to Figure 84.
8. Operate wiper
to
"park"
or
"off" position and install
crank arm.
9. Reassemble washer pump
to
wiper (fig. 75).
WASHER PUMP UNIT
The washer pump and/or valve assembly
may be re-
moved from the wiper assembly
as a
unit; therefore,
it is
not necessary
to
remove
the
wiper assembly irom
the
vehicle
if
only
the
washer pump and/or valve assembly
required service.
When
the
pump
is
removed from
the
wiper assembly,
all working parts
are
readily accessible and may easily
be serviced
as
necessary
(fig. 89).
An exploded view
of
the washer pump
is
shown in Figure 90.
Removal and Installation
1.
Raise vehicle hood.
2.
Disconnect washer hoses
and
electrical connections
from assembly.
3.
Remove
3
screws securing washer pump
and
cover
to wiper assembly. Remove pump from wiper gear
box.
4.
Position pump
and
cover assembly
to
the wiper and
install retaining screws.
5. Connect washer hoses
to
valve assembly and wiring
leads
to
pump and wiper terminals.
6. Check operation
of
unit.
CHEVROLET CHASSIS SERVICE MANUAL
ELECTRICAL-BODY
AND
CHASSIS
12-56
DEPRESSED PARK 2-SPEED WIPER
AND
WASHER
CORVETTE
GENERAL DESCRIPTION
The 2-speed windshield wiper
(fig. 91)
consists
of a
compound wound
12
volt dc motor and
a
gear box section
containing
the
gear mechanism
and
relay control.
The
motor armature
is
fitted with
a
worm gear which drives
the main gear assembly and crank arm.
The relay control, consisting
of a
relay coil, relay
armature
and
switch assembly,
is
located in the gear
box"
section and controls the starting and stopping of the wiper
through
a
latching mechanism (fig. 92).
An electric .washer pump
is
mounted
on the
gear box
section
of the
wiper
and is
driven by the wiper unit gear
assembly (fig. 93).
SERVICE OPERATIONS
WIPER MOTOR
AND
WASHER
PUMP ASSEMBLY
REMOVAL AND INSTALLATION
1.
Raise vehicle hood
and
disconnect, ground lead
at
battery.
2.
Remove engine distributor shielding
and
left bank
spark plug wire vertical shield.
3.
Disconnect left bank spark plug wire bracket-to-
manifold and position assembly to one side.
4.
Disconnect ignition resistor at firewall, then remove
washer pump inlet
and
outlet hose
at
pump valve
assembly.
5.
Remove engine distributor
cap
and position
to one
side;
then disconnect washer pump
and
motor
as-
sembly lead wires.
6. Remove glove
box
door
and
compartment. Refer
to
Section
1
for
removal procedure.
7.
Make sure wiper arms
and
wiper motor are both
in
the parked position; then remove
the
wiper trans-
mission retaining clip and disconnect both transmis-
sion and spacer from crank arm (fig. 93).
8. Remove four wiper motor-to-dash wall mounting
bolts and remove wiper motor from vehicle.
9. With
the aid of
an assistant position the wiper motor
to
the
dash wall
and
install the four motor mounting
bolts,
making sure motor assembly
is in
parked
position.
GEAR
BOX
SECTION
—<
MOUNTING
^*^
GROMMET
MOTOR
_/
SECTION
MOUNTING
/"""GROMMET
ARMATURE
END
PLAY
ADJUSTING SCREW
AND LOCK
NUT
P
^
CRANK
^_ /GROMMETS
RELAY
Fig.
92 -
Relay Control
10.
Position left transmission assembly, spacer
and
right transmission assembly
on
crank arm, then in-
stall
the
retaining clip
in the
groove
in
the crank
arm.
11.
Install glove compartment and door assembly. Refer
to Section
1
for
installation procedure.
12.
Install washer pump and motor assembly lead wires;
then install engine-distributor cap.
13.
Install washer pump inlet
and
outlet hose
to
pump
valve assembly, then install ignition resistor
to
firewall.
14.
Connect left bank spark plug wire bracket-to-mani-
fold, vertical shield and engine distributor shielding.
ROTOR
CAM. ^
CAM SLOT-~-*"'-*
WASHER PUMP^.
DRIVE
PIN
m
M
VALVE
— ASSEMBLY
i
Fig.
91 - Wiper Assembly—Corvette
Fig.
93 - Washer Pump
CHEVROLET CHASSIS SERVICE MANUAL
ELECTRICAL-BODY AND CHASSIS 12-58
RETAINER NUT
.SEAL CAP
THROUGH
BOLT,
CASE
CRANK
ARM
THRUST
BALL
FELT
WASHER
STEEL THRUST PLATE
RUBBER THRUST PLATE
SPACER WASHER
HOUSING
ARMATURE END PLAY
ADJUSTING SCREW
PAWL SPRING'
DRIVE
PAWL'
DRIVE PLATE
WASHER
ASSEMBLY
Fig.
96 - Wiper Assembly Exploded View
brush tightly, and remove instrument retaining
spring. Hold brush installed with improvised
separator as shown in Figure 95.
STOP
RETAINING
SCREW
LATCH AND
FOLLOWER
Reassembly
1.
Assemble rubber thrust disc, steel thrust plate and
felt washer in order indicated (fig. 96).
2.
Be sure steel thrust ball is located in commutator
end of armature shaft, lubricate armature shafts and
thrust ball with a high melting point grease and in-
stall armature shaft in case assembly bearing.
3.
Remove the brush retainer spring.
4.
Maintaining the armature in its assembled position in
the case, start the armature worm shaft through the
field and housing bearing until it starts to mesh with
the worm gear.
GREEN
YELLOW
STOP
TAB
RELAY
ARMATURE
Fig.
97 - Relay Disassembly
Fig. 98 - Relay Wiring
CHEVROLET CHASSIS SERVICE MANUAL