1973 DATSUN B110 oil level

I
transmission

output
shaft

They

op

erate
in
the
same

speed
as
that
of
the

output
shaft
In
other
wotds

they

operate
at

a

speed
in

proportion
to
the

vehicle

speed
To
those
valves
the

line

pressure
is

applied
as
the

input

ftom
the
control
valve

through
the

transmission
case
rear

flange
and
oil

distributor
The

governor
pressure
in

proportion
to
the

output
shaft

speed

vehicle

speed
is
led

to
the

shift

valve

of
the
control
valve

through

inverse

rou
te
as
the

output
and
thus

the

speed
change
and
the
line

pressure

are

controlled

Operation
of

secondary

governor
valve

The

secondary
valve
is
a
control

valve
which
receives

line

pressure
I

and

controls
the

governor
pressure

When
the
manual

valve
is

selected

D
2

or
1

range
line

pres

sure
is

applied
to
the

ring
shape
area
of

f
this

valve
from
circuit

I
and

this

valve
is

depressed
toward
the

center

side
Movement
of
this
valve
to
a

certain

position
closes
the
circuit

from

I
to

15

simultaneously
while
mak

ing
a

space
from
the

15
to
the
center

drain

port
and

pressure
in
the

circuit

IS
is

lowered

When

the
vehicle
is

stopped
and
the

centrifugal
force
of
this
valve
is
zero

the
valve
is

balanced
In
this
a

gover

nor

pressure
which
is
balanced
with

the

spring
force
occurs
on
the

15

When
the

vehicle
is

started
and
the

centrifugal
force
increases
this

valve

slightly
moves
to
the
outside
and

when

the

space
from

I
to
15

increases

space
from
the

15
to
the

drain

port
reduces

simultaneously
As

the
result

governor
pressure
of
the

15
increases

and
the

governor

pres

sure
is

balanced
with
the
sum
of

centrifugal
force
and
the

spring
force

The

governor

pressure
thus

changt
s
in

response
to
the

vehicle

speed

change

centrifugal
force

Operation
of

primary

governor

valve

The
valve
is

an
ON
OFF

valve

which
closes
the

governor

pressure

15

regulated
by
the

secondary

gover
CHASSIS

nor
valve
when
the
vehicle

speed

reaches
the

minimum

speed
and

when

the
vehicle

speed
exceeds
a
certain

level

open
the

governor
and
forwards

the

governor
pressure
15
to
the

control

valve

When
the

vehicle
is

stopped
the

governor

pressure
is

zero
However

when
the

vehicle
is

running
slowly

this
valve

is

depressed
to

the
center

side

and
the

groove
to

the

IS
is

closed
since
the

governor
pressure

applied
to
the

ring

shape
area
is

higher

than
the

centrifugal
force
of
this

valve

When
the

governor
speed
exceeds
cer

tain

revolution
the

governor

pressure

in
the
circuit
15
also

increases
How

ever
as
the

centrifugal
force
increases

and
exceeds

the

governor
pressure
this

valve

moves
toward
the
outside
and

the

governor
pressure
is
transmitted

to

the
circuit
15

Two
different

valves
are

employed

in
the

governor
so
that
it
will
inde

pendently
control

the

speed
at

high

speed
and
at

low

speed
That

is
within

the

low

speed

range
the

governor

pressure
is
not

generated
owing
to
the

primary
valve

whereas
at

the

high

speed
range
above
the

break

point
a

governor

pressure
regula
ted

by
the

sec0Hdary
valve
is

introduced

The
break

point
is
the

point
at

which
the

function
of
one

of
the

govp
rnors
is

transferred
to
the
other

whee

the

speed

changes
from

the

w

speed

range
to

the

high
speed

range

To
con
trol
valve

Governor

pressure

tiS

y
ID

t

4

From
control
valve

Line

pressure
I

J

I

Primary
governor

2
Secondar

governor

3
Governor
valve

body
AT090

4

Oil
distributor

5

Output
shaft

Fig
AT
7
Cross

sectional
view

of

governor

AT
6
AT091

Fig
A
T
B

Output
shaft
with
oil

distributor
and

governor

I
Oil

distributor

2

Governor
valve

body
AT092

3

Primary

governor

valve

4

Secondary

governor

valve

Fig
A

T

9

Exploded
uiew

of

gouernor

Low
in

the

range
I
is

led
to

the
low

and
reverse
clutch
from
the

line

pressure
5

through
the
line

pressure
12
and
at
the
same
time

the
same
is
led
to
the
left
end

spring

unit

Consequently
although
the

go

vernor

pressure
increases
the
valve
is

still

depressed
toward
the

right
and

the
SFV
is

fixed
in
the
Low

posi

tion
When

kicked
down

at
the

2nd

speed
the
SDV

operates
and
the

line

pressure
13
depresse
the
FSV
to

ward
the

right

Although
the

governor

pressure
15
is

considerably
high
the

valve
is

depressed
completely
toward

the

right
and
the

FSV
is

returned
to

the
Low

position
This

operation
is

called
Kick
down

shift

2nd
3rd
shift
valve
SSV

The
SSV
is

a
transfer
vaIve
which

shifts

speed
from
2nd
to
3rd

When
the
vehicle
is

stopped
the

SSV
is

depressed
toward
the

right
by
the

spring
and
is
in

the
2nd

position
It

is

provided
however
that
the
FSV

decides
the

shifting
either

to
Low

or

2nd

When
the

vehicle
is

running
the

governor

pressure
15
is

applied
to

the

right
end
surface
and
the
SSV
is

depressed
toward
the

left

Contrarily

the

spring
force
line

pressure
3
and

throttle

pressure
19

depress
the

SSV

toward
the

right

When
the

vehicle

speed
exceeds
a

certain
level
the

governor

pressure

exceeds
the
sum
of
the

spring
force

line

pressure
and
throttle

pressure
the

valve
is

depressed
toward
the
left
and

the
line

pressure
3
is
closed
Conse

quently
the
forces

are
rapidly
un

balanced
the
force
to

depress
the
SSV

toward
the

right
reduces
and
thus
the

SSV
is

depressed
to
the
Ie
ft
end

for
a

moment

With
the
SSV

depressed
to

ward
the

left
end
the
line

pressure
3

is

connected
with
the
line

pressure

10
the

band
servo
is
released
the

front
clutch
is

engaged
and

speed
is

shifted

to
3rd

When

the
accelerator

pedal
is

de

pressed
both
the
line

pressure
3

and

the
throttle

pressure
19

are

high
and
AUTOMATIC
TRANSMISSION

therefore
the

SSV
is

retained
in

2nd
unless
ihe

governor
pressure

IS
exceeds

the
line

pressure
3
and

the

throttle

pressure
19

In

the
3rd

position
force
to

depress
the

SSV
toward
the

right
is

remained

only
on
the
throttle

pressure

16
and

the
throttle

pressure
16
is

slightly
lower
than
that

toward
the

right
which
is

applied
while

shifting

from
2nd
to
3rd

Consequently
the
SSV
is
returned

to
the

2nd

position
at
a

slightly
low

speed
side

Shifting
from
3rd
to

2nd

occurs
at

a
speed

slightly
lower

than
that
for

2nd
to
3rd

shifting

When
kicked
down
at
the
3rd

line

pressure
13
is
led
from
the
SDV

and
the
SSV
is

depressed
toward
the

right
Although
the

governor
pressure

is

considerably
high
the
valve
is

de

pressed
completely
toward
the

right

and
thus
the
SSV
is
returned
to

2nd

position
This

operation
is

called
Kick
down
shift

When
the
shift
lever
is
shifted

to

2
or
I

range
at
the

3rd

speed

the
line

pressure
3
is

drained
at

the

MNV

Consequently
the
front
clutch

operating
and
band
servo

releasing
oils

are
drained
As

the

res
lIt
the
trans

mission
is
shifted

to
the
2nd
or

low

speed
although
the

SSV
is
in

the
3rd

position

When
the

speed
is
shifted
to
the

3rd
a

one

way
orifice
24
on
the

top
of
the

SSV
relieves
oil

transmitting

velocity
from
the
line

pressure
3

to

the
line

pressure
10
and
reduces
a

shock

generated
from
the

shifting

Contrarily
when
shifted
from
3rd

to
2
or

range
and
the

speed
is

shifted
to
the
2nd

spring
of
the
orifice
24
is

depressed
the
throttle

becomes
ineffective
the

line

pressure

10
is

drained

quickly
and
thus

delay
in
the

speed
shifting
is

elimi

nated

Throttle

of
the

line

pressure
6

relieves
the
oil

transmitting
velocity

from
the

line

pressure
6
to
the

line

pressure
10
when

the
lever
is

shifted

to
the

R

range
and
relieves
drain

velocity
from
the
line

pressure
10
to

the
line

pressure
6

when

shifting

from
3rd
to

2nd
at

the
D

range
Thus
the
throttle
of
the
line

pressure
6
reduces

a
shock

generated

from
the

shifting

A

plug
in
the
SSV
left

end

readjust

the
throttle

pressure
16
which
varie

depending
on
the

engine
throttle
con

dition
to
a

throttle

pressure
19

suited
to
the

speed
change
control

Moreover
the

plug
is

a
valve
which

applies
line

pressure
13
in

lieu
of
the

throttle

pressure
to
the

SSV
and
the

FSV
when
kick

down
is

performed

When
the
throttle

pressure
16
is

applied
to
the
left
side
of
this

plug

and
the

plug
is

depressed
toward
the

right
a
slight

space
is
made
from
the

throttle

pressure
16
to

19
A
throt

tIe

pressure
19
which
is
lower

by
the

pressure
loss

equivalent
to
this

space
is

generated
the

pressure
loss
is
added
to

the

spring
force
and
thus

the

plug
is

depressed
back
from
the

right
to
the

left

When
this

pressure
19
increases

excessively
the

plug
is
further
de

pressed
toward
the
left

space
from

the

throttle

pressure
19
to
the
drain

circuit

13
increases
and
the
throttle

pressure
19
lowers
Thus
the

plug
is

balanced
and
the

throttle

pressure

19
is
reduced
in
a

certain
value
b

3
Orifice

t

checking
valve

24

15

2
2

i
I

1
c

V
Y
ii
pr

W
jt1

iff
I
W
q

I
nHH

J

L19
H
10

15

AT
9
A

T098

Fig
AT

13
2nd
3rd

shiflvalue

against
the

throttle

pressure
16

When

performing
the

kick
down

the

SOV

moves
a

high
line

pressure
is

led
to

the
circuit
19

from
the
line

pressute
circuit
13

which
had

been

drained
the

plug
is

depressed
toward

the
left

and
the
circuit

19
becomes

equal
to
the

line

pressure
13
Thus

the

kick
down
is

performed

Preasure
modifier
valve

PMV

In

comparison
with
the

operating

pressure
required
in

starting
the

vehi

ele

power

transmitting
capacity
of
the

clutch

in
other

words

required
op

erating
pressure
may
be

lower
when

the

vehicle
is
once

started
When
the

line

pressure
is
retained
in

a

high
level

up
to
a

high
vehicle

speed
a
shock

generated
from
the

shifting
increases

and
the
oil

pump
loss
also

increases
In

order
to

prevent
the
above

described

defective
occurrences
with

the

opera

lion

of
the

governor
pressure
15
the

throttle

pressure
must
be

changed
over

to

reduce
the

line

pressure
The
PMV

is
used

for
this

purpose

When
the

governor

pressure
15

which
is

applied
to

the

right
side
of

the

PMV
is

low
the
valve
is

depressed

toward

the

right
by
the

throttle

pres

sure

16

applied
to

the
area

differ

ence
of

the
value
and
the

spring
force

and

the
circuit

from
the

circuit
16
to

the

circuit
18
is

closed

However

when

the

vehicle

speed
increases
and

the

governor

pressure
15
exceeds
a

certain

level
the

governor

pressure

toward

the
left

which
is

applied
to
the

right
side

exceeds
the

spring
force
and

the

throttle

pressure
16
toward
the

right
the
valve
is

depressed
toward
the

left
and
the

throttle

pressure
is

led

from
the
circuit

16
to

the

circuit

18
This

throttle

pressure
18
is

applied
to

the

top
of
the

PRY

and

pressure
of
the
line

pressure
source
7

is

reduced

Contrarily
when
the
vehi

cle

speed
lowers
and
the

governor

pressure
15
lowers
the

force
toward

the

right
exceeds
the

governor
pres
CHASSIS

sure
the
valve
is

depressed
back
to

ward
the

right
the

throttle

pressure

18
is
drained
to

the

spring
unit

This

valve
is

switched
when
the

throttle

pressure
and
the

governor

pressure
are

high
or
when

the
throttle

pressure
is

low
and
the

governor

pres

sure
is
low

II

18
16

1JU

k
I

15

AT099

Fig
AT
14
Pressure

modifier
valve

Vacuum
throttle
valve

VTV

The

vacuum

throttle
valve
is
a

regulator
valve

which
uses

the
line

pressure
7
for
the

pressure
source

and

regulates
the

throttle

pressure
16

which

is

proportioned
to
the

force

of

the

vacuum

diaphragm
The

vacuum

diaphragm
varies

depending
on
the

engine
throttle
condition

negative

pressure
in
the

intake
line

When
the
line

pressure
7
is

ap

plied
to

the
bottom

through
the
valve

hole

and
the

valve
is

depressed

up

ward

space
from
the

line

pressure
7

to
the

throttle

pressure
16
is

closed

and
the

space
from
the

throttle

pres

sure

16
to
the

drain
circuit
17
is

about
to

open
In

this

the
throttle

pressure
16
becomes
lower

than
the

line

pressure
7

by
the

pressure

equivalent
to
the

pressure
loss

of
the

space
and
the

force
to

depress

through
the

rod
of
the

vacuum

dia

phragm
is

balanced
with
the

throttle

pressure
16

applied
upward
to

the

bottom

When

the

engine
torque
is

high
the

negative
pressure
in
the

intake

line

rises

similar
to
the

atmospheric
pres

sure
and
the

force
of

the
rod
to

depress
the
valve

increases

As
the

result
the
valve
is

depressed
down

ward
the

space
from
the
throttle

pressure
16
to

the
drain

17
re

AT

lO
duces
and
the

space
from
the

line

pressure
7
to
the

throttle

pressure

16
increases

Consequently
the

throttle

pressure

16
increases

and
the

valve
is

baI

anced

Contrarily
when

the

engine

torque
lowers
and
the

negative
pres

sure
in

the
intake
line
lowers

similar

to
vacuum
force
of

the
rod

to
de

press
the

valve
lowers
and
the

throttle

pressure

16
also

lowers

When
a

pressure
regulated
by
the
throttle

back

up
valve
described
in

the
subse

quent

paragraph
is

led

to
the
circuit

17
a

high

pressure
is

applied

through

the

space
from
the
circuit
17

to
the

throttle

pressure
16

Consequently

the
VTV
is

unbalanced
the

throttle

pressure
16
becomes

equal
to

the

back

up
ptessure
17
and
the
valve
is

locked

upward

bi

II
I

ATlOa

Fig
AT
15
Vacuum

throttle

valve

Throttle

back

up
valve
TBV

Usually
this
valve
is

depressed

downward

by
the

spring
force

and
the

circuit

17
is

drained

upward

As

soon
as
the
lever
is

shfted
either

to
2
or

range
line

pressure
is

led

from
the
circuit
4

the
line

pressure
is

applied
to
the
area
differ

ence
of
the
valve

the
valve
is

depres

sed

upward
the

space
from
the
circuit

4

to
the

circuit

17
is

timely
closed

and
with
the

space
from

the
circuit

17
to
the

upper
drain

being
about
to

open
the

back

up

pressure
17
which

is

lower
than
the

line

pressure
4

by

the

pressure
loss
due
to
the

space
from

the
circuit
4
to
the
circuit

17
is

balanced
with
the

spring
force

Further
when

speed
is

shifted
from

2nd
to

Low
at

the

range
I

line

pressure
is

led
from
the

circuit

12

and
the
line

pressure
is

applied

upward

to
the
bottom

of
the

valve

through
the

valve
hole

Consequently
the

valve
is

depressed
upward
and
locked
As
the

result

the

space
from
the

line

pressure

4
to
the

back

up
pressure
17

is

closed

completely
and

the
back

up

pressure
17
is
drained

upward

AT101

Fig
AT
16

Throttle
back

up
valve

Solenoid
downshift
valve

SDV

This
valve
is

a
transfer
valve
which

leads
the

line

pressure
7

to
13
and

transmits
the

same
to
the
FSV
and

SSV
when
a
kick
down

signal
is
re

ceived
from

the
downshift
solenoid

Usually
the
solenoid

push
rod
and

valve
are
locked

upward
by
the

spring

in

the
lower
end
and
circuit
from
the

line

pressure
4
to
the
line

pressure

13
is

opened

When

kick
down
is

performed
the

push
rod

operates
the
valve
is

depres

sed
downward
and
the
circuit

from

the
line

pressure
7

to
the
line

pres

sure

13
opens
The
line

pressure
13

opposes
the

governor
pressure
15
at

the
SSV
and
FSV
and

thus

performs

the
downshift

operation
AUTOMATIC
TRANSMISSION

AT102

Fig
AT

17
Solenoid

downshift
value

Second
lock
valve
SLV

This
valve
is
a

transfer
valve
which

assists

the
shift
valve
in
order
to

decide

the
fixed
2nd

speed
at
the
2

range

In
the

D

range
the
sum
of

the

spring
force
and

line

pressure
3

applied
upward
exceeds

the
line

pres

sure
2

which
is

applied
to
the

valve

area

difference
as
the

downward

force

As
the

result
the

valve
is

locked

upward
and
the

circuit

from
the
line

pressure
8
to
the

line

pressure
9
is

opened

Consequently
the
FSV
becomes

the
2nd

speed
condition
and
line

pressure
is

led
to
the

band
servo

engaging
circuit
9

only
when
the
line

pressure

1
is
released

to
the
line

pressure
8

In
the

2

range
the

upward
force

is

retained

only
on

the

spring
and

the

downward

line

pressure
2
exceeds

the

upward
force

As

the
result
the

valve
is

locked

downward
the
line

pressure
2
is

released

to
9

regardless
of

the

operat

ing
condition
of
the
FSV
and

the

band

servo
is

engaged

2nd
3rd

timing
valve

TMV

This

valve
is

a
transfer
valve
which

switches
the

by
pass
circuit
of
the

AT
ll
J

2

3

ATl03

Fig
A
T
18

Second
lock

ualue

orifice
22
in

the
front
clutch

pres

sure
circuit
II
in

response
to
the

vehicle

speed
and
the

throttle
con

dition
A
force
created

when
the

go

vernor

pressure
15

applies
to
the

bottom
of
the

TMV
is

used
for
the

upward
force
and
a

force
created

when

the

spring
force

and
the

throttle

pressure

apply
to
the

top
of
the

TMV

is
used
for

the
downward
force

When
the

throttle

pressure
16
is

lower
than

the

governor
pressure
15

the

upward
force

exceeds
the
down

ward
force
the
valve
is
locked

upward

and

passage
from
the
circuit
10

2nd
from
the

Top
to
the
circuit

II
is

closed

Consequently
the

line

pressure
10
is
led
to

the
front

clutch

circuit

1
I

through
the

orifice
22

and

thus
the
oil

pressure
is
trans

mitted

slowly
However
under

the

normal

shifting
the

throttle

pressure

16
has
a

pressure
exceeding
a
certain

level
and

the
downward
force
exceeds

the

upward
force
As
the
result
the

valve
is
locked
downward
the

passage

from
the
circuit

10
to
the
circuit

1
I
is

opened
and
the

orifice
22

is

disregarded

1

i
16

I
O

11

l1
1

r

X

lp

I
15

J

AT104

Fig
AT
19
2nd

3rd

timing
ualue

Fig
A
T
49

Torque
converter

aligning
cut

3
When

connecting
torque
con

verter

to
transmission

measure
dis

tance
A

to
be

certain
that

they
are

correctly
assembled
See

Figure

AT
50

Distance
A

More
than
16
5
IllIll

0
650
in

A

AT117

Fig
A
T
50

Installing
torque
converter
CHASSIS

4
Bolt
converter
to
drive

plate

Tightening
torque

0
8

to
1
0

kg
Ill
5
8
to
7
2
ft
Ib

Note

Align
chalk

marks

painted
a

cross

both

parts
during
disas

sembling
processes

5

After
converter
is
installed

rotate

crankshaft

several
turns
and
check
to

be
sure
that

transmission
rotates

freely

without

binding

6
Pour

recommended
automatic

transmission
fluid

up
to

correct
level

through
oil

charge

pipe

7

Connect
manual

lever
to

shift

rod

Operation
should
be
carried

out

with
manual
and

selector
levers
in

N

8
Connect

inhibitor
switch
wires

Notes

a
Refer
to

covering
topic

under

Checking
and

adjusting

inhibitor
switch
on

page

AT
51

b

Inspect
and

adjust
switch
as

above
whenever
it
has

to
be

removed
for

service

9
Check
inhibitor
switch
for

op

eration

AT
34
Starter
should

be

brought
into

op

eration

only
when
selector
lever
is
in

P
and
N

positions
it

should
not

be

started
when
lever
is
in
D

2

1
and
R

positions

Back

up
lamp
should
also

light

when
selector
lever
is

placed
in
R

position

10
Check
level
of
oil
in

transmis

sion
For
detailed

procedure
see

page

AT
49

II
Move

selector
lever

through
all

positions
to
be
sure
that
transmission

operates
correctly

With
hand
brake

applied
rotate

engine
at

idling
Without

disturbing

the

above

setting
move

selector
lever

through
N

to
D

to
2
to
I

and
to
R
A

slight
shock
should
be

felt

by
hand

gripping
selector
each

time
transmission
is

shifted

Note
See

page
AT

50
for

checking

enigne

idling

12

Check
to
be

sure
that
line

pres

sure
is
correct

To

do
this
refer
to

relative

topic
under

Testing
line

pres

sure
on

page
AT
53

13

Perform

stall
test

as

per
the

instructions
on

page
AT

51

Removal
and

installation

I

Disconnect
control
knob
from

hand
lever

by
removing
a
screw

Remove

console
box

Disconnect
shift
rod

from
cross

shaft

4
Remove

hand
lever

hand
lever

shaft
and
shift
rod

assembly
with

bracket

To

install
reverse
the

order
of

removal
CHASSIS

Adjustment

The

adjustment
of

linkage
is

as

important
as

Inspection
of
Oil

Level

for
the
automatic

transmission

Therefore

great
care
should

be

exercised
because
defective

adjustment

will

result
in

the
breakdown
of

the

transmission

Loosen

adjust
nuts

@
See

Figure
AT

51

2
Set
hand

lever

CD
and

selector

range
lever

@
at
N

position
See

Figure
AT
51

AT

36
3

Set
lower

shift
rod

@
to

trunnion

@
by

turning
in
or

out

adjust
nuts
See

Figure
AT
I

After

adjusting
make
sure

that

hand
lever
can
be

set
in

any
position

correctly
and
that
hand
lever

operates

properly
without

any

binding

If
levers
do
not

operate
satisfactori

ly

readjust
or

replace
parts
as
neces

sary

AUTOMATIC
TRANSMISSIO
N

TROUBLE
DIAGNOSES
AND
ADJUSTMENT

INSPECTION
AND
ADJUSTMENT

BEFORE
TROUBLE
DIAGNOSIS

Testing
instrument
for

inspection

Checking
oil
level

Inspection
and

repair
of
oil

leakage

Checking
engine

idling
rpm

Checking
and

adjusting
kick
down
switch

and
downshift
solenoid

Inspection
and

adjustment
of
manual

linkage

Checking
and

adjusting
inhibitor
switch

STALL
TEST

Stall

test

procedures

Judgement

As
the
troubles
on

the
automatic

transmission
can
be

mostly
repaired
by

doing
simple
adjustment
so
do

not

disassemble

immediately
if
the

auto

m
tic
transmission
is
in
trouble

Firstly
inspect
and

adjust
the
auto

matic
transmission
with

mounting
on

vehicle

by
observing
the

trouble

shooting
chart

If
the

trouble
could
not
be

solved

by
this

procedure
then

remove
and

disassemble
the
automatic
transmis

sion
It

is
advisable
to
check

overhaul

and

repair
each

point
in
the

order

itemized
in

the
trouble

shooting

chart

l
In
the

trouble

shooting
chart

the

diagnosis
items

are

arranged
in
the

order
from

easy
to

difficult
and
there

fore

please
follow
these
items

The

transmission
should
not
be
removed

unless

necessary

2
The

test
and

adjustment
for
trou

ble

diagnosis
should
be
made

on
the

basis
of
standard
values
and
the
data

should
be
recorded
ROAD
TEST

Car

speed
at

gear
shift

Checking
speed

changing
condition

Checking
items

during
speed
change

Shift
schedule

LINE
PRESSURE
TEST

Line

pressure
governor
feed

pressure

Judgement
in

measuring
line

pressure

TROUBLE
SHOOTING
CHART

Inspecting
items

Trouble

shooting
chart
for
3N71
B
Automatic

Transmission

Trouble

shooting
guide
for
3N718
Automatic

Transmission
CONTENTS

AT
49

AT
49

AT
49

AT
50

AT
50

AT
50

AT
51

AT
51

AT
51

AT51

AT
52

INSPECTION
AND

AD
JUSTMENT

BEFORE

TROUBLE

DIAGNOSIS

Testing
instrument
for

inspection

1

Engine
tachometer

2
Vacuum

gauge

3
Oil

pressure
gauge

It

is
convenient
to

install
these

instruments
in
a

way
that
allows

meas

urements
to
be
made

from
the
driver
s

seat

Checking
oil

level

In

checking
the
automatic
transmis

sion
the
oil

level
and

the
condition
of

oil
around

the
oil
level

gauge
should
be

examined

every
5

000
km
3
000

miles
These

steps
are

easy
and

effec

live

in
trouble

shooting
as
some

change
of
oil
conditions
are

linked

with

developed
troubles
in

many
cases

AT
49
AT
52

AT
52

AT
53

AT
53

AT
53

AT
53

AT
53

AT
54

AT
54

AT
54

AT
55

AT
5B

For
instance

Lack

of
oil
causes
defective

opera

tion

by
making
the
clutches
and

brakes

slip
developing
severe

wear

The

cause
of

this

operation
is
that

the

oil

pump
has

begun
to

suck
air

which

caused
oil

foaming
thus

rapidly

deteriora

ting
the
oil

quality
and

pro

ducing
sludge
and

varnish

Meanwhile
excessive
oil
is
also
bad

as
in
the

case
of

a
lack

of
oil
because

of
oil

foaming
by
being
stirred

up
by

the

gears
Moreover
in

high
speed

driving
with
excessive
oil
in
the
trans

mission
the
oil

often
blows
out
from

the
breather

I

Measuring
oil
level

When

checking
the
fluid
level
start

the

engine
and
run
it
until
normal

operating
temperatures
oil

tempera

ture
50
to

800e
122
to
176
F

Approximately
ten
minute

operation

will
elevate
the

temperature
to
this

range
and

enigne
idling
conditions

are
stabilized
Then

apply
the
brakes

and
move
the
transmission

shift
lever

through
all
drive

positions
and

place

the
lever
in

park
P

position
In
this

inspection
the
car
must
be

placed
on
a

level
surface

The
amount
of
the
oil

varies
with

the

temperature
As
a
rule
the
oil

level

must
be

measured
after
its

tempera

ture
becomes

sufficiently
high

I
Fill
the
oil

to
the
line
H

The

difference
of

capacities
between
both

H

and
L

is

approximately
0
4

liter
7
8

U
S

pt
3
4

Imper

pt
and

therefore
take

care
not
to
fill

beyond

the

line
H

2
At
the
time
of
the

above

topping
up
and

changing
of
oil
care

should
be
taken
of
to

prevent
mixing

the
oil
with
dust
and

water

2

Inspecting
oil
condition

The
condition
of
oil

sticking
to
the

level

gauge
indicates
whether
to
over

haul
and

repair
the
transmission

or

look

for
the

defective

part

If
the

oil
has
deteriorated
into

a

varnish
like

quality
it

causes
the
con

trol
valve
to

stick
The
blackened
oil

gives
the

proof
of
the
burned
clutch

brake
band

etc
In

these
cases
the

transmission
must
be

replaced

Notes
a
In

oil
level

checking
use

special

paper
waste
to

handle

the
level

gauge
and
take

care

not
to
let
the

scraps
of

paper

and
cloth

tick
to
the

gauge

b
Insert

the

gauge
fully
and

take

it
out

quickly
before

splashing
oil
adheres
to
the

gauge
and
theu
observe
the

level

c

Use
automatic
transmission

fluid

having
DEXRON

iden

tIficatIon

only
in
the
3N71
B

automatic
transmission

d

Pay
atteutIon

because
the

oil
to

be
used
dIffers
from
that

i

used

in
the
Nissan
Full

Automatic

Transmission

3N7IA

Never
mix
the
oil
with

that
CHASSIS

Inspection
and

repair
of
oil

leakage

When
oil

leakage
takes

place
the

portion
near
the

leakage
is
covered

with
oil

presenting
difficulty
in
de

tecting
the

spot
Therefore
the

places

where
oil

seals
and

gaskets
are

equipped
are

enumerated
below

I
Converter

housing

The
rubber

ring
of

oil

pump
hous

ing

The
oil

eaI
of
oil

pump
housing

The
oil

seal
of

engine
crankshaft

The
bolts
of
converter

housing
to

case

2

Transmission
and
rear
extension

Junction
of
transmission
and
rear

extension

Oil
tube
connectors

Oil

pan

Oil

pressure
inspection
holes
Refer

to

Figure
AT

112

The

mounting
portion
of
vacuum

diaphragm
and

downshift
solenoid

Breather

and
oil

charging

pipe

Speedometer
pinion
sleeve

The
oil
seal

of
rear
extension

To

exactly
locate

the

place
of
oil

leakage
proceeds
as
follows

Place
the

vehicle
in
a

pit
and

by

sampling
the

leaked
oil
examine

whe

ther

it
is
the

torq
le
converter
oil
or

not

The

torque
converter
oil

assumes

color
like
red
wine

when

shipped

from
the

factory
so
it
is

ea

ily
distin

guished
from

engine
oil

or

gear
oil

Cleanly
wipe
off
the

leaking
oil
and

dust
and
detect

the

spot
of
oil

leakage

Use
nonflammable

organic
solvent

such
as
carbon

tetrachloride
for

wip

ing

Raise
the

oil

temperature
by

op

erating
the

engine
and

shift
the

lever

to
0
to

heighten
the

oil

pressure

The

spot
of
oil

leakage
will
then

be

found

more

easily

Note

A

the
oil

leakage
from
the

breather
does
not
take

place

except
when

running
at

high

speed
it
is

impossible
to
locate

the

spot
of

leakage
with
vehicle

stalled

AT
50
Checking
engine
idling

rprn

The

engine
idling
revolution
should

be

properly

adjusted

If
the

engine
revolution
is

too
low

the

engine
does
not

operate
smoothly

and
if

too

high
a

strong
shock
or

creep
develops
when

changing
over

from
N

to
D
or

R

Specified

idling
speed

650

rpm
at
D

position

800

rpm
at
N

position

Checking
and

adjusting
kick

down
switch
and

downshift

solenoid

When
the

kick
down

operation
is

not
made

properly
or

the

speed
chang

ing
point
is
too

high
check
the

kick

down
switch

downshift
solenoid
and

wiring
between
them

When
the

igni

tion

key
is

positioned
at
the

1st

stage

and
the

accelerator

pedal
is

depressed

deeply
the
switch
contact
should
be

closed
and
the

solenoid
should
click

If

it

does
not
click
it

indicates

a
defect

Then
check

each

part
with

the

testing

instruments

See

Figure
AT
I09

0
0

1
M

r

7

I

Y

ATl08

Fig
A
T
l

09

Downshift
solenoid

Note

Watch
for
oil

leakage
from

transmission
case