Chevrolet 70 1969 Series, Shop Manual

Page: 37 / 913

C AB A N D BODY M O U NTING S 1-10
WIPER DRIVE UNIT
PARTIAL
DISASSEMBLY AND
ASSEMBLY
N O T E : This procedure is necessary to obtain
access to wiper motor parking switch contacts for
cleaning, checking or replacement.
D ISA SSEM B LY (Refer to Fig. 12)
N O T E : If unit is equipped with washer pump,
remove the pump. Also pry the pump cam from
shaft.
1. Clamp crank arm in a vise, then remove
attaching nut. Separate arm from shaft.
2. Remove retaining ring and end play washer
from output shaft.
3. Remove cover from over gears.
N O T E : Drill out six attaching rivets. Mark
ground strap location for reassembly purposes.
4. Remove output gear and shaft assembly
from mounting plate bushing,
5. If condition warrants replacement of wiring
terminal board and parking switch contacts, first
mark wires, then unsolder at terminal lugs. Drill
out three rivets which attach terminal board to
motor mounting plate. Remove terminal board.
Figure 13— Washer Pump Attaching Screws
A S S E M B L Y (Refer to Fig. 12)
1. Install new terminal and parking switch as­
sembly to motor mounting plate with three rivets.
N O T E : Rivets are included in package with new
terminal board.
2. Referring to marks made on wires prior to
disassembly, solder wires to terminal lugs.
3. Install spring washer over idler gear shaft
pin (if removed). Apply small quantity of special
lubricant available from United Motors Stations,
and identified as AC640 to idler gear shaft pin,
then install idler gear.
4. Install output shaft and gear assembly in
motor mounting plate bushing. Apply A C 640 lubri­
cant sparingly to gear teeth.
5. Operate motor and stop it in "Park" posi­
tion.
6. Install cover over gears and secure cover
with six small screws and nuts. N O T E : Screws
are included in Repair Kit package.
7. Install end play washer and retaining ring
over end of output shaft. Make sure ring is seated
fully in shaft groove,
8. Referring to figure which shows proper
relationship of crank arm alignment marks with
marks on gear cover, place crank arm on shaft as
shown. N O T E : This view shows marks on conven­
tional cab motor only. Install crank arm nut and
tighten it firmly.
9. If equipped with washer pump, install drive
cam and pump assembly.
WINDSHIELD
WASHER
PUMP
G E N E RA L IN F O R M A T IO N
The
“ E ”
type washer pump used on the “ E ”
type rectangular non-depressed park wiper motors
resembles previous models somewhat in physical
appearance but it has been changed considerably
internally. Refer to Figure 13 for view of pump
mounted on wiper motor assembly. Past model
pumps used a bellows system for the pumping
mechanism whereas the new design incorporates
a piston enclosed in a plastic cylinder housing.
The piston type pump provides higher pressures
and increased volume (fig. 15).
The basic principle of operation is very sim­
ilar to past model pumps of this type. The pumping
mechanism is powered by a four- lobe cam which
is pressed on wiper motor output shaft. This cam
CHEVROLET SERIES 70-80 HEAVY DUTY TRUCK SH OP M ANUAL