Chevrolet 10 Series 1968, Service Manual

Page: 487 / 713

CLUTCHES AND TRANSMISSIONS 7-24
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
Rem oval
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 control
cable, remove tapered pin and pull lever out. Replace
the two “ O” 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.
ELECTRICAL UNIT CHECKS
Overdrive Relay
Specifications and checking procedures for this relay
are as follows:
F ig . 13C—C h eckin g Relay A ir G ap
A ir Gap ......................................... O il inch minimum
Point Opening ............................................... 025 inch
Closing V o l t a g e ................................... 8.3-10.2 volts
Armature Sealing Voltage . . . . 11.2 volts maximum
Three checks and adjustments are required on the
overdrive relay; air gap, point opening and closing volt­
age. The air gap contact point opening checks and ad­
justments should be made with the battery disconnected.
A ir G ap
The air gap should not normally require adjustment
unless the relay has been misadjusted. Check the air gap
with the points barely touching and adjust if necessary by
bending the lower point support (fig. 13C).
Point O pening
Check the contact point opening and adjust by bending
the upper armature stop (fig. 14C).
Closing Voltage
To check the relay closing voltage, connect a potenti­
ometer or variable resistance of sufficient value (not less
F ig . 14C— A djusting Relay Point Opening
— (CHECK WITH
*= POINTS BARELY
TOUCHING) *
POINT SUPPORT
(BEND TO ADJUST AIR GAP)
i
UPPER ARMATURE STOP
(BEND TO ADJUST POINT OPENING)
PO IN T O P E N IN G
CHEVROLET TRUCK SERVICE MANUAL