Chevrolet 10 Series 1967, Service Manual

Page: 405 / 605

CLUTCHES AND TRANSMISSIONS 7-19
To test for this condition, remove solenoid
cover, pull dash control knob out, roll car
2
ft.
forward. Push dash control in, turn ignition
switch on. Then ground the "KD" terminal of
relay, and watch movement of center stem of
solenoid. It should not move more than 1/8" when
the solenoid clicks. Then, with the relay terminal
still grounded, shift into low gear, and roll car
forward by hand. Solenoid stem should then move
an additional 3 /8 ", as the pawl engages fully.
These two tests indicate proper blocker action.
Unless both tests are met, the blocker ring is
probably not in the correct position.
3. Engages with a severe jolt or noise
Insufficient blocker ring friction may cause the ring
to lose its grip on the hub of the sun gear control
plate. Check the fit and tension of the ring as de­
scribed under "Cleaning and Inspection".
4. Free-wheels at speeds over 30 MPH
If cam roller retainer spring tension is weak the unit
will free wheel at all times. Check spring action as
described under "Cleaning and Inspection".
ELECTRICAL
Any one of the following general complaints may be due
to electrical trouble in the overdrive circuit.
1. Does not engage.
2. Does not release.
3. Does not kickdown from overdrive.
These troubles may be traced and remedied as de­
scribed in the following paragraphs.
1. Does not engage
a. With the ignition switch on, ground the "KD" ter­
minal of the solenoid relay with a jumper lead. If
the solenoid clicks, the relay and solenoid cir­
cuits are in operating condition. If no click is
heard in the relay, check the fuse and replace if
defective.
b. If the fuse is good, use a second jumper lead to
connect the "SOL" and "BAT" terminals of the
relay. If a click is now heard in the solenoid, the
relay is probably at fault and should be repaired
or replaced.
c. If the solenoid does not click in Step b, check the
wiring to the No. 4 terminal of the solenoid and
replace if necessary. If the wiring is not defec­
tive, the trouble is probably in the solenoid. Re­
move the solenoid cover, examine the solenoid
contacts in series with the pull-in winding and
clean if necessary. Test again for clicks, as in
Step b, after replacing solenoid cover and lead
wires. Replace the solenoid if trouble has not
been corrected.
d. If the relay and solenoid circuits are in good con­
dition as determined in Step a, leave the ignition
switch on and make sure the manual control knob
is in the overdrive position. Ground one and then
the other of the two terminals next to the stem of
the kickdown switch (identified as "SW" and
"R EL"). If the solenoid clicks when one terminal
is grounded but not the other, replace the switch.
If the solenoid does not click when either of the
terminals is grounded, check the wiring between
the relay and the kickdown switch and replace if
defective.
e. If the solenoid clicks as each terminal is
grounded in Step d, ground the governor switch
terminal. If the solenoid clicks, the governor
switch may be defective. If the solenoid does not
click, check the wiring between the kickdown and
governor switches and replace if necessary.
2. Does not release
a. Remove the connection to the "KD” terminal of
the relay. If this releases overdrive, look for a
grounded control circuit between the relay and
governor switch.
b. If the overdrive is not released in Step a, discon­
nect the lead to the "SOL” terminal of relay. If
this releases the overdrive, replace the relay.
3. Does not kickdown from overdrive
a. With the engine running, connect a jumper lead
between the No.
6
terminal of the solenoid and
ground. Operate the kickdown switch by hand.
This should stop the engine. If it does, the sole­
noid is probably defective and it should be
checked for dirty ground-out contacts or other
defects within the ground-out circuit of the sole­
noid (fig. 4B). Clean the contacts or replace the
contact plate as required.
b. If the engine does not stop in Step a, ground one
and then the other of the two terminals (identified
as "IGN" and "SOL") farthest from the stem of
the kickdown switch. The engine should stop when
one of the two terminals (IGN) is grounded. If the
engine does not stop when the terminal is
grounded, the wiring or connections to the switch
between the switch and coil are defective. When
the other terminal (SOL) is grounded, the engine
should stop when the kickdown switch is operated.
If the engine does not stop when the kickdown
switch is operated with the second terminal
grounded, the kickdown switch is defective. If the
trouble is in the kickdown switch, adjust the link­
age to give more travel of the switch rod. If this
does not correct the trouble, replace the kickdown
switch.
If the kickdown switch operates as it should,
check for an open circuit in the wiring between
the kickdown switch and the No.
6
terminal of the
solenoid.
c. If the trouble is not located by the above checks,
the upper contacts of the kickdown switch may not
be opening. To check for this condition, ground
the overdrive control circuit at the governor
switch. This should cause the solenoid to click.
Operate the kickdown switch by hand. This should
cause a second click as the solenoid releases. If
there is no second click, adjust the linkage to give
more travel of the switch rod. If this does not
correct the trouble, replace the kickdown switch.
CHEVROLET TRUCK SERVICE M ANUAL