Chevrolet 30 Series 1967 Service Manual page 402

CLUTCHES AND TRANSMISSIONS 7-16
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.
out of the adapter.
CASE REAR OIL SEAL
Removal
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 screwdriver in lock plate slot in fitting and pry fit­
ting, gear and shaft from housing. Pry "O" ring from
groove in guide.
Install new "0 " 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 fo r this relay
MAINTENANCE AND ADJUSTMENTS
The oil seal may be pried
are as follows:
Air Gap...................................................... Oil inch minimum
Point Opening.............................................................. 025 inch
Closing V o lta g e ..........................................
Armature Sealing
Voltage..........................................
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.
Air Gap
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. IB).
Point Opening
Check the contact point opening and adjust by bending
the upper armature stop (fig. 2B).
Closing V o lta g e
To check the relay closing voltage, connect a potentiom­
eter or variable resistance of sufficient value (not less
than 50 ohms) in series with the "KD" terminal, connect a
voltmeter to the "IGN" and "KD" terminals. With the ig­
nition switch on, slowly decrease the amount of re sist­
ance in order to check the relay closing voltage (the
overdrive solenoid and relay should click when the relay
closes). Adjust the closing voltage by bending the arma­
ture spring post (fig. 3B).
closing voltage and bend up to decrease the closing
voltage.
To check the sealing voltage, increase the voltage after
the relay closes until the armature seals against the
core. Decrease the sealing voltage by reducing the relay
a ir gap.
(CHECK WITH
^ POINTS BARELY
(BEND TO ADJUST AIR GAP)
^ TOUCHING)
Fig . IB - Checking Relay A ir Gap
8.3-10.2 volts
11.2 volts maximum
Bend down to increase the
POINT SUPPORT
1
h — ■ ■ ■ *
..... ... --.....
CHEVROLET TRUCK SERVICE M ANUAL