1979 DATSUN 210 oil pressure

Condition

Clutch
chatters

Noisy
clutch

Clutch

grabs
Clutch

Probable
cause
and

testing
Corr
ctive
action

Clutch

chattering
is

usually
noticeable
when
car
is

just
rolled
off
with
clutch

parlially

engaged

Weak
or

broken
clutch
disc
torsion

spring

Oil
or

grease
on
clutch

facing

Clutch

facing
out

of

proper
contact
or

clutch
disc
runout

Loose
rivets

Warped
pressure
plate
or
clutch
cover

surface

Unevenness
of

diaphragm

spring
toe

height

Loose

engine
mounting
or
deteriorated

rubber

A
noise
is

heard
after

clutch
is

disengaged

Damaged
release

bearing

A

noise
is

heard
when
clutch
is

disengaged

Insufficient

grease
on
the

sliding
surface

of

bearing
sleeve

Clutch
cover

and

bearing
are
not

in

stalled

correctly
Replace

Replace

Replace

Replace

Repair
or

replace

Adjust
or

replace

Retighten
or

replace

I
Replace

Apply
grease

Adjust

A
noise
is
heard
when
car

is

suddenly
rolled
off
with

clutch

partially
engaged

Damaged
pilot
bushing

I
Replace

When

grabbing
of
clutch
occurs
car
will
not
roll
off

smoothly
from
a

standing
start
or
clutch

will

be

engaged
before
clutch

pedal
is

fully
depressed

Oil
or

grease
on
clutch

facing

Clutch

facing
worn
or

loose
rivets

Wear

or
rust

on
splines
in
drive
shaft

and
clutch
disc

Warped
flywheel
or

pressure
plate

Loose

mountings
for

engine
or

power

train

units

CL13
Replace

Replace

Clean
or

replace

Repair
or

replace

Retighten

Automatic
Transmission

HYDRAULIC
CONTROL
UNIT
AND

VALVES

The

hydraulic
or
a
tomatic
control

system
is

comprised
of
four
4
basic

groups
the

pressure
supply
system

the

pressure
regulating
system
the

flow
control
valves
and
the
friction

elements

PRESSURE
SUPPLY
SYSTEM

The

pressure
supply
system
consists

of

a

gear

type
oil

pwnp
driven

by
the

engine
through
the

torque
converter

The

pump
provides

pressure
for
aU

hydraulic
and
lubrication
needs

PRESSURE
REGULATOR

VALVES

The

pressure
regulating
valves
con

trol
the

output
pressure
of
the
oil

pump

Pre
ure

rellulator
valve

The

pressure
regulator
valve
con

trois
mainline

pressure
based
on

throttle

opening
for
the

operation
of

the
band
clutches
and

brake

Governor

valve

The

governor
valve
transmits

re

gulated
pressure
based
on
car

peed

to
the

shift
valves
to
control

upshifts

and
downshifts

Vacuum
throttle
valve

The
vacuum

throttle
valve
transmits

regulated
pressure
based
on

engine

load
vacuum
This

pressure
controls

the

pressure
regulator
valve

Also
this

pressure
is

applied
to
one
end
of
the

shift
valves
in

opposition
to

governor

pressure
which
acts

on
the
other

end

of
the
shift
valves

controlling

upshift

and
downshift

speeds
FLOW
CONTROL
VALVES

Manual
valve

The
manual
valve
is
moved

manual

Iy
by
the
car

operator
to
select
the

different
drive

ranges

1
2
ShHt
valve

The
1
2

shift
valve

automaticaIly

shifts
the
transmission
from
first

to

second
or
from
second
to
first

depend

ing

upon
governor
and
throttle

pres

sure

along
with

accelerator

position

solenoid
downshift
valve
See

Hy

draulic
Control
Circuits
Drive

2

2
3
ShHt
valve

The
2
3
shift
valve

automaticaIly

shifts
the
transmission
from
second
to

top
gear
or
from

top
to
second
de

pending

upon
governor
and
throttle

pressure
or
accelerator

position
sole

noid
downshift
valve

See
Hydraulic

Control
Circuits
Drive
3

Range

2
3

Tlmlnll
valve

For
2
3
shifts
a
restrictive
orifice

slows
the

application
fluid
to
the
front

clutch
while
the

slower

reacting
band

is
allowed
to
release
This

prevents
a

hard
2
3
or
3
2
shift
Under

heavy

load
however
the

engine
will
tend
to

run

away
during
the
2
3

or
3
2
shift

pause
therefore
a
2
3

timing
valve

using
throttle
and

governor

pressure
is

used
to

bypass
the

restrictive
orifice

during
such

heavy
load
conditions

Solenoid
down
hHt
valve

The
solenoid
downshift
valve
is

activated

electrically
when
the
ac

celerator
is
f1oor
d

causing
a
forced

downshift
from

top
to
second

top
to

first
or

second
to

first

gear
depending

upon
car

speed
governor

pressure

AT
3
Pre
ure
modified
valve

The

pressure
modifier

valve
assists

the
mainline

pressure

regulator
valve
in

lowering
mainline

pressure
during

high

speed

light
load
conditions
such
as

steady

speed
cruise

Governor

pres

sure

working

against
a

spring

opens

the

valve
which
aUows

modified
throt

tle

pressure
to
work

against
the

pres

sure

regulator
valve

spring
lowering

mainline

pressure
Lower

operating

pressure
under

light
load

reduces
oil

temperature
and
increases
transmis

sian
life

Throttle
back
up
valve

The
throttle

back

up
valve
assists

the
vacuum
throttle
valve
to

increase

line

pressure
when
the
manual
valve
is

shifted

either
to

2
or
I

range

Second
lock
valve

The

second
lock
valve
is

used
to

bypa
the
1
2

shift
valve

to
maintain

the
band

apply

pressure
in
2

posi

tion
The
valve
is
also
used
as
an
oil

passage
for
the
1
2

shift
valve

band

apply

pressure
in

D2

D3
and

12
Range

CLUTCHES
AND
BAND

SERVOS

The

servo

pistons
of
the
clutches

low

reverse
brake
and

band
are
moved

hydraulically
to

engage
the

clutches

brake
and

apply
the
band
The
clutch

and

brake
istons

are
released

by

spring
tension

and
band

piston
is

released

by
spring
tension

and

hy

draulic

pressure

OIL
CHANNEL

IDENTIFICATION

The
circuit
numbers
shown
in
each

Hydraulic
Control
Circuit
are

classified

as
follows
according
to
the

function

Pressure
source
of
the
line
7

Operating
line

pressure
for

friction
elements

I
2
3
4
5
6

g
9

10
11
12

Auxiliary
line

pressure
13

Torque
converter

pressure
14

Governor

pressure
15

Throttle

system
pressure

16
17
18

19

Oil
pump
discharge
hole
7

f
Torque
converter

pressure
14

Rear
clutch

pressure
1

Front
clutch

pressure
11

W
h0i1
pu
6
suction
hote

e

8

IIlIlJJIII
Automatic
Transmission

L

f

AT106

Fig
AT
5

Oil
Channela
in
Cou
Front
Face

lo
o

o
0

Oil

pump
discharge
hole
7
Governor

pressure
15

1

h

Torque
converter
I

pressure
14
0
0

Servo
release

Rear
clutch

l
press
re

10
r

L

Governor
reed

pressure
1

pressure
1
Servo

tlghtemng

li
nb

o

0

pressure
9

r

Front

clutch
fI
Low
reverse
brake

pressure
12

pressure
11

U
0

111
1

1
P
u
n

e

AT107

ATlOS

Fig
A
T
4

Oil
Channell
in
Oil
Pump
Fig
A
T
6
Oil
Channell
in
Cou
Fac

MECHANICAL
OPERATION

In

the
3N71B
automatic
transmis

sion
each

part
operates
as
shown
in

the

following
table
at
each
gear
select

position
RanKe
Cm

ratio
Clutch
Low
A

Front
Rear

brake
One

w

y

dutch
Parkin

pa
l
Band
servo

Operation
Release

Park
on
on

Reftrst
2
182
on

on
on

Neutral

Dl
Lo
2
458
on

on

Drift
02
Second
1
458
on

03

Top
1
000
on
on
on

2
Second
1
4
8
on
on

12
Second
1458
on
on

Low
2
4
8
on
on

Note
The
low
brake
is

applied
in

11
raiW
to

prevent
free
whee6ng

when
coasting
and
aIlows
engine

braking

AT
5

D
ran
Low
r

Oil

pump

l

t

Torque

convlrter

pr
ur

rlgula
Tor

yalvl

t

t

1

L

Line

pr
ur

l

Governor

preslur
Automatic
Transmission

Fr
on1

clutch
Rear

cl
ulch

t

l

Torque
conyert

pressure

Throttle

pr
iur
Brake

ba
n
d

o

h
Band

I
b
rvo

I
Low

0
nd

reven
brQke

t

l

Thralll

pre
ur

t

1V

Governor

pre
sur

AT448

Fig
AT
J3
Oil
Pr
ure
Circuit

Diagrom
D

rang
Low

gear

AT13

0
ren
e
2nd

gear

1
Oil

pump

l
t

ra

d

l

t
Tor

q
UI

convlrt
r

Prlssure

rlQulotor

valvl
Automatic
Transmission

Front

clutch

tt1t

P
RN021
Rear

clutch
Brake

band
LOllii
ond

rlverse
brake

Govern
or

preslure
t

Line

pressure

Governor

pre
ur

j

iiiiB
Torque
canverter
prollure

Throttle

pre
ur

AT448

Fir
AT
15
Oil
Pr
re
Circuit
D
m
D

rang
2nd

g
ar

AT15

D3
ran

3rd
g
ar

Oi
I

pump

1

t

Torque
J

C
onYlrt
r

I
i

t
t

Pressure

reQula
or

Ya
lye

L
i
ns

pressure

Goyernor

pressure
Automatic
Transmission

Front

clurch
Rlar

clutch
Brake

bond
Low

and

rever
brake

0

thBond
L
B
so

J
1

1

1

lt

r
T

tr
Throttle

pressure

t

t

I

@

t

Governor

pr
au
r

Torque
canYlr
er

pr
ssure

rIA
Throttle

pressure

AT449

Fill
AT
17
Oil

Pro
ure
Circuit

Diagram

D3
range
3rd

gear

AT
17

D
RANGEKICKDOWN

To
achieve
a
forced
downshift
from

3rd
to
2nd
the

car

speed
must
be

under

approximately
100
km
h

60

mph
from
2nd

to
1st
il

must
be

under

approximately
50

km
h
30

mph
Fully
depressing
the
accelerator

pedal
energizes

jhe
dow
hift
sole

noid
which

opem
the

solenoid
down

shift
valve
Oil

pressure
is
then
exerted

against
the
shift
valves
Between
50

and
100
km
h
30
and
60

mph
this

pressure
will

close
the
2nd
3rd
shift

vd
t

go
mor

pressure
and

the
car
downshifts
When
the
car

speed

is
below

50
km
h
30

mph
the

Ist

2nd
shift
valve
will
be
closed
and

the
transmission
will
be
in
Isl

gear
A

car

speed
and

governor
pressure
in

crease
the
shift
valves

automaticaJJy

reopen
Autom
tic
Transmission

AT
18

4
Bolt
converter
to

drive
plate

Note

Align
chalk
mark

painted
a

cro5S
both

parts
during
disas

sembling
p

S
After
converter
is

installed
rotat

r
nkshait
veral
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
m
mual
and
selector
levers
in

N

8

Connect
inhibitor
switch
wires
Automatic
Transmission

NOte

a
Refer

to

page
AT40
for

Checking

and

Adjusting
Inhibitor
Switch

b

Inspect
end

edjust
switch
as

abo

whe
ever
it
has

to
be
removed
for

servi
e

9

Check
inhibitor

switch
for

op

eration

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
n

and
Ru

positions

Back

up

lamp
should
Iso

light

when
selector
lever
is

placed
in
R

position

10
Check
level
of
oil
in

transm

sion
For
detailed

procedure
see

page

AT39

AT

26
II
Move

selector
leve

through
all

positions
to
be

sure
that
transmission

operates
correctly

With
hand

brake

applied
rotate

engine
at

idling
Without

disturbing

the
above

seUlng
move
selector

lever

through
N

to
D
to
2

to
I

and
to

R
A

slight
shock
should
be

reU

by

handgripping
selector

each

time
transmission

is
shifted

Note
See

page
AT40
for

Checking

Engine
Idling
Revolution

12
Check

to
be
sure
that

line

pres

sure
is

correct
To
do
this
refer
to

page
AT
43
for
Line
Pressure
Test

13

Perform
stan
test
as
described
in

page
AT41